src/bin/lttng-sessiond/ust-field-convert.cpp

   1 /*
   2  * Copyright (C) 2022 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #include "field.hpp"
   9 #include "ust-app.hpp"
  10 #include "ust-field-quirks.hpp"
  11 #include "ust-registry-session.hpp"
  12 #include "ust-registry.hpp"
  13
  14 #include <common/exception.hpp>
  15 #include <common/make-unique.hpp>
  16
  17 #include <unordered_map>
  18 #include <utility>
  19
  20 namespace lst = lttng::sessiond::trace;
  21 namespace lsu = lttng::sessiond::ust;
  22
  23 /*
  24  * fmtlib helper that must be under the same namespace as lttng_ust_ctl_abstract_types
  25  * (global).
  26  */
  27 static int format_as(lttng_ust_ctl_abstract_types type)
  28 {
  29         return fmt::underlying(type);
  30 }
  31
  32 namespace {
  33 /*
  34  * Type enclosing the session information that may be required during the decoding
  35  * of the lttng_ust_ctl_field array provided by applications on registration of
  36  * an event.
  37  */
  38 class session_attributes {
  39 public:
  40         using registry_enum_getter_fn =
  41                 std::function<lsu::registry_enum::const_rcu_protected_reference(const char *name,
  42                                                                                 uint64_t id)>;
  43
  44         session_attributes(registry_enum_getter_fn reg_enum_getter,
  45                            lst::byte_order native_trace_byte_order) :
  46                 get_registry_enum{ std::move(reg_enum_getter) },
  47                 _native_trace_byte_order{ native_trace_byte_order }
  48         {
  49         }
  50
  51         const registry_enum_getter_fn get_registry_enum;
  52         const lst::byte_order _native_trace_byte_order;
  53 };
  54
  55 /* Used to publish fields on which a field being decoded has an implicit dependency. */
  56 using publish_field_fn = std::function<void(lst::field::uptr)>;
  57
  58 /* Look-up field from a field location. */
  59 using lookup_field_fn = std::function<const lst::field&(const lst::field_location&)>;
  60
  61 lst::type::cuptr
  62 create_type_from_ust_ctl_fields(const lttng_ust_ctl_field *current,
  63                                 const lttng_ust_ctl_field *end,
  64                                 const session_attributes& session_attributes,
  65                                 const lttng_ust_ctl_field **next_ust_ctl_field,
  66                                 const publish_field_fn& publish_field,
  67                                 const lookup_field_fn& lookup_field,
  68                                 lst::field_location::root lookup_root,
  69                                 lst::field_location::elements& current_field_location_elements,
  70                                 lsu::ctl_field_quirks quirks);
  71
  72 void create_field_from_ust_ctl_fields(const lttng_ust_ctl_field *current,
  73                                       const lttng_ust_ctl_field *end,
  74                                       const session_attributes& session_attributes,
  75                                       const lttng_ust_ctl_field **next_ust_ctl_field,
  76                                       const publish_field_fn& publish_field,
  77                                       const lookup_field_fn& lookup_field,
  78                                       lst::field_location::root lookup_root,
  79                                       lst::field_location::elements& current_field_location_elements,
  80                                       lsu::ctl_field_quirks quirks);
  81
  82 template <class UstCtlEncodingType>
  83 enum lst::null_terminated_string_type::encoding
  84 ust_ctl_encoding_to_string_field_encoding(UstCtlEncodingType encoding)
  85 {
  86         static const std::unordered_map<UstCtlEncodingType,
  87                                         enum lst::null_terminated_string_type::encoding>
  88                 encoding_conversion_map = {
  89                         { (UstCtlEncodingType) lttng_ust_ctl_encode_ASCII,
  90                           lst::null_terminated_string_type::encoding::ASCII },
  91                         { (UstCtlEncodingType) lttng_ust_ctl_encode_UTF8,
  92                           lst::null_terminated_string_type::encoding::UTF8 },
  93                 };
  94
  95         const auto encoding_it = encoding_conversion_map.find(encoding);
  96         if (encoding_it == encoding_conversion_map.end()) {
  97                 LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
  98                         "Unknown lttng_ust_ctl_string_encodings value `{}` encountered when decoding integer field",
  99                         encoding));
 100         }
 101
 102         return encoding_it->second;
 103 }
 104
 105 template <class UstCtlBaseType>
 106 enum lst::integer_type::base ust_ctl_base_to_integer_field_base(UstCtlBaseType base)
 107 {
 108         static const std::unordered_map<UstCtlBaseType, enum lst::integer_type::base>
 109                 base_conversion_map = { { 2, lst::integer_type::base::BINARY },
 110                                         { 8, lst::integer_type::base::OCTAL },
 111                                         { 10, lst::integer_type::base::DECIMAL },
 112                                         { 16, lst::integer_type::base::HEXADECIMAL } };
 113
 114         const auto base_it = base_conversion_map.find(base);
 115         if (base_it == base_conversion_map.end()) {
 116                 LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 117                         "Unknown integer base value `{}` encountered when decoding integer field",
 118                         base));
 119         }
 120
 121         return base_it->second;
 122 }
 123
 124 lst::type::cuptr
 125 create_integer_type_from_ust_ctl_fields(const lttng_ust_ctl_field *current,
 126                                         const lttng_ust_ctl_field *end,
 127                                         const session_attributes& session_attributes,
 128                                         const lttng_ust_ctl_field **next_ust_ctl_field,
 129                                         lsu::ctl_field_quirks quirks __attribute__((unused)))
 130 {
 131         if (current >= end) {
 132                 LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 133                         "End of {} array reached unexpectedly during decoding", typeid(*current)));
 134         }
 135
 136         const auto base = ust_ctl_base_to_integer_field_base(current->type.u.integer.base);
 137         const auto signedness = current->type.u.integer.signedness ?
 138                 lst::integer_type::signedness::SIGNED :
 139                 lst::integer_type::signedness::UNSIGNED;
 140         const auto byte_order = current->type.u.integer.reverse_byte_order ?
 141                 lst::type::reverse_byte_order(session_attributes._native_trace_byte_order) :
 142                 session_attributes._native_trace_byte_order;
 143
 144         *next_ust_ctl_field = current + 1;
 145
 146         return lttng::make_unique<const lst::integer_type>(current->type.u.integer.alignment,
 147                                                            byte_order,
 148                                                            current->type.u.integer.size,
 149                                                            signedness,
 150                                                            base);
 151 }
 152
 153 lst::type::cuptr
 154 create_floating_point_type_from_ust_ctl_fields(const lttng_ust_ctl_field *current,
 155                                                const lttng_ust_ctl_field *end,
 156                                                const session_attributes& session_attributes,
 157                                                const lttng_ust_ctl_field **next_ust_ctl_field,
 158                                                lsu::ctl_field_quirks quirks __attribute__((unused)))
 159 {
 160         if (current >= end) {
 161                 LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 162                         "End of {} array reached unexpectedly during decoding", typeid(*current)));
 163         }
 164
 165         *next_ust_ctl_field = current + 1;
 166
 167         const auto byte_order = current->type.u._float.reverse_byte_order ?
 168                 lst::type::reverse_byte_order(session_attributes._native_trace_byte_order) :
 169                 session_attributes._native_trace_byte_order;
 170
 171         try {
 172                 return lttng::make_unique<const lst::floating_point_type>(
 173                         current->type.u._float.alignment,
 174                         byte_order,
 175                         current->type.u._float.exp_dig,
 176                         current->type.u._float.mant_dig);
 177         } catch (lttng::invalid_argument_error& ex) {
 178                 LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 179                         "Invalid floating point attribute in {}: {}", typeid(*current), ex.what()));
 180         }
 181 }
 182
 183 lst::type::cuptr
 184 create_enumeration_type_from_ust_ctl_fields(const lttng_ust_ctl_field *current,
 185                                             const lttng_ust_ctl_field *end,
 186                                             const session_attributes& session_attributes,
 187                                             const lttng_ust_ctl_field **next_ust_ctl_field,
 188                                             lsu::ctl_field_quirks quirks __attribute__((unused)))
 189 {
 190         if (current >= end) {
 191                 LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 192                         "End of {} array reached unexpectedly during decoding", typeid(*current)));
 193         }
 194
 195         uint64_t enumeration_id;
 196         const auto& enum_uctl_field = *current;
 197         const char *enumeration_name;
 198         const auto *enum_container_uctl_type =
 199                 &current->type.u.legacy.basic.enumeration.container_type;
 200
 201         if (enum_uctl_field.type.atype == lttng_ust_ctl_atype_enum_nestable) {
 202                 /* Nestable enumeration fields are followed by their container type. */
 203                 ++current;
 204                 if (current >= end) {
 205                         LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 206                                 "Array of {} is too short to contain nestable enumeration's container",
 207                                 typeid(*current)));
 208                 }
 209
 210                 if (current->type.atype != lttng_ust_ctl_atype_integer) {
 211                         LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 212                                 "Invalid type of nestable enum container: type id = {}",
 213                                 current->type.atype));
 214                 }
 215
 216                 enum_container_uctl_type = &current->type.u.integer;
 217                 enumeration_id = enum_uctl_field.type.u.enum_nestable.id;
 218                 enumeration_name = enum_uctl_field.type.u.enum_nestable.name;
 219         } else {
 220                 enumeration_id = enum_uctl_field.type.u.legacy.basic.enumeration.id;
 221                 enumeration_name = enum_uctl_field.type.u.legacy.basic.enumeration.name;
 222         }
 223
 224         *next_ust_ctl_field = current + 1;
 225
 226         const auto base = ust_ctl_base_to_integer_field_base(enum_container_uctl_type->base);
 227         const auto byte_order = enum_container_uctl_type->reverse_byte_order ?
 228                 lst::integer_type::reverse_byte_order(session_attributes._native_trace_byte_order) :
 229                 session_attributes._native_trace_byte_order;
 230         const auto signedness = enum_container_uctl_type->signedness ?
 231                 lst::integer_type::signedness::SIGNED :
 232                 lst::integer_type::signedness::UNSIGNED;
 233
 234         if (signedness == lst::integer_type::signedness::SIGNED) {
 235                 const auto& enum_registry = static_cast<const lsu::registry_signed_enum&>(
 236                         *session_attributes.get_registry_enum(enumeration_name, enumeration_id));
 237
 238                 return lttng::make_unique<const lst::signed_enumeration_type>(
 239                         enum_container_uctl_type->alignment,
 240                         byte_order,
 241                         enum_container_uctl_type->size,
 242                         base,
 243                         enum_registry._mappings);
 244         } else {
 245                 const auto& enum_registry = static_cast<const lsu::registry_unsigned_enum&>(
 246                         *session_attributes.get_registry_enum(enumeration_name, enumeration_id));
 247
 248                 return lttng::make_unique<const lst::unsigned_enumeration_type>(
 249                         enum_container_uctl_type->alignment,
 250                         byte_order,
 251                         enum_container_uctl_type->size,
 252                         base,
 253                         enum_registry._mappings);
 254         }
 255 }
 256
 257 lst::type::cuptr
 258 create_string_type_from_ust_ctl_fields(const lttng_ust_ctl_field *current,
 259                                        const lttng_ust_ctl_field *end,
 260                                        const session_attributes& session_attributes
 261                                        __attribute__((unused)),
 262                                        const lttng_ust_ctl_field **next_ust_ctl_field,
 263                                        lsu::ctl_field_quirks quirks __attribute__((unused)))
 264 {
 265         if (current >= end) {
 266                 LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 267                         "End of {} array reached unexpectedly during decoding", typeid(*current)));
 268         }
 269
 270         const auto& string_uctl_field = *current;
 271         *next_ust_ctl_field = current + 1;
 272
 273         const auto encoding =
 274                 ust_ctl_encoding_to_string_field_encoding(string_uctl_field.type.u.string.encoding);
 275
 276         return lttng::make_unique<const lst::null_terminated_string_type>(1, encoding);
 277 }
 278
 279 lst::type::cuptr
 280 create_integer_type_from_ust_ctl_basic_type(const lttng_ust_ctl_basic_type& type,
 281                                             const session_attributes& session_attributes)
 282 {
 283         /* Checked by caller. */
 284         LTTNG_ASSERT(type.atype == lttng_ust_ctl_atype_integer);
 285
 286         const auto byte_order = type.u.basic.integer.reverse_byte_order ?
 287                 lst::integer_type::reverse_byte_order(session_attributes._native_trace_byte_order) :
 288                 session_attributes._native_trace_byte_order;
 289         const auto signedness = type.u.basic.integer.signedness ?
 290                 lst::integer_type::signedness::SIGNED :
 291                 lst::integer_type::signedness::UNSIGNED;
 292         const auto base = ust_ctl_base_to_integer_field_base(type.u.basic.integer.base);
 293         const auto size = type.u.basic.integer.size;
 294         const auto alignment = type.u.basic.integer.alignment;
 295
 296         return lttng::make_unique<const lst::integer_type>(
 297                 alignment, byte_order, size, signedness, base);
 298 }
 299
 300 lst::type::cuptr
 301 create_array_type_from_ust_ctl_fields(const lttng_ust_ctl_field *current,
 302                                       const lttng_ust_ctl_field *end,
 303                                       const session_attributes& session_attributes,
 304                                       const lttng_ust_ctl_field **next_ust_ctl_field,
 305                                       lsu::ctl_field_quirks quirks __attribute__((unused)))
 306 {
 307         if (current >= end) {
 308                 LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 309                         "End of {} array reached unexpectedly during decoding", typeid(*current)));
 310         }
 311
 312         const auto& array_uctl_field = *current;
 313         uint32_t array_alignment, array_length;
 314         lst::type::cuptr element_type;
 315         nonstd::optional<enum lst::string_type::encoding> element_encoding;
 316
 317         array_length = array_uctl_field.type.u.legacy.array.length;
 318         array_alignment = 0;
 319
 320         const auto& element_uctl_type = array_uctl_field.type.u.legacy.array.elem_type;
 321         if (element_uctl_type.atype != lttng_ust_ctl_atype_integer) {
 322                 LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 323                         "Unexpected legacy array element type: atype = {}, expected atype = lttng_ust_ctl_atype_integer ({})",
 324                         element_uctl_type.atype,
 325                         lttng_ust_ctl_atype_integer));
 326         }
 327
 328         element_type =
 329                 create_integer_type_from_ust_ctl_basic_type(element_uctl_type, session_attributes);
 330         if (element_uctl_type.atype == lttng_ust_ctl_atype_integer &&
 331             element_uctl_type.u.basic.integer.encoding != lttng_ust_ctl_encode_none) {
 332                 /* Element represents a text character. */
 333                 element_encoding = ust_ctl_encoding_to_string_field_encoding(
 334                         element_uctl_type.u.basic.integer.encoding);
 335         }
 336
 337         *next_ust_ctl_field = current + 1;
 338
 339         if (element_encoding) {
 340                 const auto integer_element_size =
 341                         static_cast<const lst::integer_type&>(*element_type).size;
 342
 343                 if (integer_element_size != 8) {
 344                         LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 345                                 "Unexpected legacy array element type: integer has encoding but size is not 8: size = {}",
 346                                 integer_element_size));
 347                 }
 348
 349                 /* Array is a static-length string. */
 350                 return lttng::make_unique<lst::static_length_string_type>(
 351                         array_alignment, *element_encoding, array_length);
 352         }
 353
 354         return lttng::make_unique<lst::static_length_array_type>(
 355                 array_alignment, std::move(element_type), array_length);
 356 }
 357
 358 lst::type::cuptr create_array_nestable_type_from_ust_ctl_fields(
 359         const lttng_ust_ctl_field *current,
 360         const lttng_ust_ctl_field *end,
 361         const session_attributes& session_attributes,
 362         const lttng_ust_ctl_field **next_ust_ctl_field,
 363         const publish_field_fn& publish_field,
 364         const lookup_field_fn& lookup_field,
 365         lst::field_location::root lookup_root,
 366         lst::field_location::elements& current_field_location_elements,
 367         lsu::ctl_field_quirks quirks)
 368 {
 369         if (current >= end) {
 370                 LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 371                         "End of {} array reached unexpectedly during decoding", typeid(*current)));
 372         }
 373
 374         const auto& array_uctl_field = *current;
 375         uint32_t array_alignment, array_length;
 376         lst::type::cuptr element_type;
 377         nonstd::optional<enum lst::string_type::encoding> element_encoding;
 378
 379         array_length = array_uctl_field.type.u.array_nestable.length;
 380         array_alignment = array_uctl_field.type.u.array_nestable.alignment;
 381
 382         /* Nestable array fields are followed by their element type. */
 383         const auto& element_uctl_field = *(current + 1);
 384
 385         /* next_ust_ctl_field is updated as needed. */
 386         element_type = create_type_from_ust_ctl_fields(&element_uctl_field,
 387                                                        end,
 388                                                        session_attributes,
 389                                                        next_ust_ctl_field,
 390                                                        publish_field,
 391                                                        lookup_field,
 392                                                        lookup_root,
 393                                                        current_field_location_elements,
 394                                                        quirks);
 395         if (element_uctl_field.type.atype == lttng_ust_ctl_atype_integer &&
 396             element_uctl_field.type.u.integer.encoding != lttng_ust_ctl_encode_none) {
 397                 /* Element represents a text character. */
 398                 element_encoding = ust_ctl_encoding_to_string_field_encoding(
 399                         element_uctl_field.type.u.integer.encoding);
 400         }
 401
 402         if (element_encoding) {
 403                 const auto integer_element_size =
 404                         static_cast<const lst::integer_type&>(*element_type).size;
 405
 406                 if (integer_element_size != 8) {
 407                         LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 408                                 "Unexpected array element type: integer has encoding but size is not 8: size = {}",
 409                                 integer_element_size));
 410                 }
 411
 412                 /* Array is a static-length string. */
 413                 return lttng::make_unique<lst::static_length_string_type>(
 414                         array_alignment, *element_encoding, array_length);
 415         }
 416
 417         return lttng::make_unique<lst::static_length_array_type>(
 418                 array_alignment, std::move(element_type), array_length);
 419 }
 420
 421 /*
 422  * For legacy sequence types, LTTng-UST expresses both the sequence and sequence
 423  * length as part of the same lttng_ust_ctl_field entry.
 424  */
 425 lst::type::cuptr create_sequence_type_from_ust_ctl_fields(
 426         const lttng_ust_ctl_field *current,
 427         const lttng_ust_ctl_field *end,
 428         const session_attributes& session_attributes,
 429         const lttng_ust_ctl_field **next_ust_ctl_field,
 430         const publish_field_fn& publish_field,
 431         lst::field_location::root lookup_root,
 432         lst::field_location::elements& current_field_location_elements,
 433         lsu::ctl_field_quirks quirks __attribute__((unused)))
 434 {
 435         if (current >= end) {
 436                 LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 437                         "End of {} array reached unexpectedly during decoding", typeid(*current)));
 438         }
 439
 440         const auto& sequence_uctl_field = *current;
 441         const auto& element_uctl_type = sequence_uctl_field.type.u.legacy.sequence.elem_type;
 442         const auto& length_uctl_type = sequence_uctl_field.type.u.legacy.sequence.length_type;
 443         const auto sequence_alignment = 0U;
 444
 445         if (element_uctl_type.atype != lttng_ust_ctl_atype_integer) {
 446                 LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 447                         "Unexpected legacy sequence element type: atype = {}, expected atype = lttng_ust_ctl_atype_integer ({})",
 448                         element_uctl_type.atype,
 449                         lttng_ust_ctl_atype_integer));
 450         }
 451
 452         if (length_uctl_type.atype != lttng_ust_ctl_atype_integer) {
 453                 LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 454                         "Unexpected legacy sequence length field type: atype = {}, expected atype = lttng_ust_ctl_atype_integer ({})",
 455                         length_uctl_type.atype,
 456                         lttng_ust_ctl_atype_integer));
 457         }
 458
 459         nonstd::optional<enum lst::string_type::encoding> element_encoding;
 460         if (element_uctl_type.atype == lttng_ust_ctl_atype_integer &&
 461             element_uctl_type.u.basic.integer.encoding != lttng_ust_ctl_encode_none) {
 462                 /* Element represents a text character. */
 463                 element_encoding = ust_ctl_encoding_to_string_field_encoding(
 464                         element_uctl_type.u.basic.integer.encoding);
 465         }
 466
 467         auto length_field_name = lttng::format("_{}_length", sequence_uctl_field.name);
 468         auto element_type =
 469                 create_integer_type_from_ust_ctl_basic_type(element_uctl_type, session_attributes);
 470         auto length_type =
 471                 create_integer_type_from_ust_ctl_basic_type(length_uctl_type, session_attributes);
 472
 473         lst::field_location::elements length_field_location_elements =
 474                 current_field_location_elements;
 475         length_field_location_elements.emplace_back(length_field_name);
 476
 477         lst::field_location length_field_location{ lookup_root,
 478                                                    std::move(length_field_location_elements) };
 479
 480         /* Publish an implicit length field _before_ the sequence field. */
 481         publish_field(lttng::make_unique<lst::field>(std::move(length_field_name),
 482                                                      std::move(length_type)));
 483
 484         *next_ust_ctl_field = current + 1;
 485
 486         if (element_encoding) {
 487                 const auto integer_element_size =
 488                         static_cast<const lst::integer_type&>(*element_type).size;
 489
 490                 if (integer_element_size != 8) {
 491                         LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 492                                 "Unexpected legacy array element type: integer has encoding but size is not 8: size = {}",
 493                                 integer_element_size));
 494                 }
 495
 496                 /* Sequence is a dynamic-length string. */
 497                 return lttng::make_unique<lst::dynamic_length_string_type>(
 498                         sequence_alignment, *element_encoding, std::move(length_field_location));
 499         }
 500
 501         return lttng::make_unique<lst::dynamic_length_array_type>(
 502                 sequence_alignment, std::move(element_type), std::move(length_field_location));
 503 }
 504
 505 lst::type::cuptr create_sequence_nestable_type_from_ust_ctl_fields(
 506         const lttng_ust_ctl_field *current,
 507         const lttng_ust_ctl_field *end,
 508         const session_attributes& session_attributes,
 509         const lttng_ust_ctl_field **next_ust_ctl_field,
 510         const publish_field_fn& publish_field,
 511         const lookup_field_fn& lookup_field,
 512         lst::field_location::root lookup_root,
 513         lst::field_location::elements& current_field_location_elements,
 514         lsu::ctl_field_quirks quirks)
 515 {
 516         if (current >= end) {
 517                 LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 518                         "End of {} array reached unexpectedly during decoding", typeid(*current)));
 519         }
 520
 521         const auto& sequence_uctl_field = *current;
 522         const auto sequence_alignment = sequence_uctl_field.type.u.sequence_nestable.alignment;
 523         const auto *length_field_name = sequence_uctl_field.type.u.sequence_nestable.length_name;
 524
 525         /* Nestable sequence fields are followed by their element type. */
 526         const auto& element_uctl_field = *(current + 1);
 527
 528         nonstd::optional<enum lst::string_type::encoding> element_encoding;
 529         if (element_uctl_field.type.atype == lttng_ust_ctl_atype_integer &&
 530             element_uctl_field.type.u.integer.encoding != lttng_ust_ctl_encode_none) {
 531                 /* Element represents a text character. */
 532                 element_encoding = ust_ctl_encoding_to_string_field_encoding(
 533                         element_uctl_field.type.u.integer.encoding);
 534         }
 535
 536         /* next_ust_ctl_field is updated as needed. */
 537         auto element_type = create_type_from_ust_ctl_fields(&element_uctl_field,
 538                                                             end,
 539                                                             session_attributes,
 540                                                             next_ust_ctl_field,
 541                                                             publish_field,
 542                                                             lookup_field,
 543                                                             lookup_root,
 544                                                             current_field_location_elements,
 545                                                             quirks);
 546
 547         if (lttng_strnlen(sequence_uctl_field.type.u.sequence_nestable.length_name,
 548                           sizeof(sequence_uctl_field.type.u.sequence_nestable.length_name)) ==
 549             sizeof(sequence_uctl_field.type.u.sequence_nestable.length_name)) {
 550                 LTTNG_THROW_PROTOCOL_ERROR("Sequence length field name is not null terminated");
 551         }
 552
 553         lst::field_location::elements length_field_location_elements =
 554                 current_field_location_elements;
 555         length_field_location_elements.emplace_back(length_field_name);
 556
 557         lst::field_location length_field_location{ lookup_root,
 558                                                    std::move(length_field_location_elements) };
 559
 560         /* Validate existence of length field (throws if not found). */
 561         const auto& length_field = lookup_field(length_field_location);
 562         const auto *integer_selector_field =
 563                 dynamic_cast<const lst::integer_type *>(&length_field.get_type());
 564         if (!integer_selector_field) {
 565                 LTTNG_THROW_PROTOCOL_ERROR(
 566                         "Invalid selector field type referenced from sequence: expected integer or enumeration");
 567         }
 568
 569         if (element_encoding) {
 570                 const auto integer_element_size =
 571                         static_cast<const lst::integer_type&>(*element_type).size;
 572
 573                 if (integer_element_size != 8) {
 574                         LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 575                                 "Unexpected array element type: integer has encoding but size is not 8: size = {}",
 576                                 integer_element_size));
 577                 }
 578
 579                 /* Sqeuence is a dynamic-length string. */
 580                 return lttng::make_unique<lst::dynamic_length_string_type>(
 581                         sequence_alignment, *element_encoding, std::move(length_field_location));
 582         }
 583
 584         return lttng::make_unique<lst::dynamic_length_array_type>(
 585                 sequence_alignment, std::move(element_type), std::move(length_field_location));
 586 }
 587
 588 lst::type::cuptr
 589 create_structure_field_from_ust_ctl_fields(const lttng_ust_ctl_field *current,
 590                                            const lttng_ust_ctl_field *end,
 591                                            const session_attributes& session_attributes
 592                                            __attribute__((unused)),
 593                                            const lttng_ust_ctl_field **next_ust_ctl_field,
 594                                            lsu::ctl_field_quirks quirks __attribute__((unused)))
 595 {
 596         if (current >= end) {
 597                 LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 598                         "End of {} array reached unexpectedly during decoding", typeid(*current)));
 599         }
 600
 601         uint32_t field_count;
 602         uint32_t alignment;
 603         const auto& structure_uctl_field = *current;
 604
 605         if (structure_uctl_field.type.atype == lttng_ust_ctl_atype_struct) {
 606                 field_count = structure_uctl_field.type.u.legacy._struct.nr_fields;
 607                 alignment = 0;
 608         } else {
 609                 field_count = structure_uctl_field.type.u.struct_nestable.nr_fields;
 610                 alignment = structure_uctl_field.type.u.struct_nestable.alignment;
 611         }
 612
 613         if (field_count != 0) {
 614                 LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 615                         "Only empty structures are supported by LTTng-UST: nr_fields = {}",
 616                         field_count));
 617         }
 618
 619         *next_ust_ctl_field = current + 1;
 620         return lttng::make_unique<lst::structure_type>(alignment, lst::structure_type::fields());
 621 }
 622
 623 template <class VariantSelectorMappingIntegerType>
 624 typename lst::variant_type<VariantSelectorMappingIntegerType>::choices
 625 create_typed_variant_choices(const lttng_ust_ctl_field *current,
 626                              const lttng_ust_ctl_field *end,
 627                              const session_attributes& session_attributes,
 628                              const lttng_ust_ctl_field **next_ust_ctl_field,
 629                              lookup_field_fn lookup_field,
 630                              lst::field_location::root lookup_root,
 631                              lst::field_location::elements& current_field_location_elements,
 632                              unsigned int choice_count,
 633                              const lst::field& selector_field,
 634                              lsu::ctl_field_quirks quirks)
 635 {
 636         typename lst::variant_type<VariantSelectorMappingIntegerType>::choices choices;
 637         const auto& typed_enumeration =
 638                 static_cast<const lst::typed_enumeration_type<VariantSelectorMappingIntegerType>&>(
 639                         selector_field.get_type());
 640
 641         for (unsigned int i = 0; i < choice_count; i++) {
 642                 create_field_from_ust_ctl_fields(
 643                         current,
 644                         end,
 645                         session_attributes,
 646                         next_ust_ctl_field,
 647                         [&choices, &typed_enumeration, &selector_field, quirks](
 648                                 lst::field::uptr field) {
 649                                 /*
 650                                  * Find the enumeration mapping that matches the
 651                                  * field's name.
 652                                  */
 653                                 const auto mapping_it = std::find_if(
 654                                         typed_enumeration.mappings_->begin(),
 655                                         typed_enumeration.mappings_->end(),
 656                                         [&field,
 657                                          quirks](const typename std::remove_reference<
 658                                                  decltype(typed_enumeration)>::type::mapping&
 659                                                          mapping) {
 660                                                 if (static_cast<bool>(
 661                                                             quirks &
 662                                                             lsu::ctl_field_quirks::
 663                                                                     UNDERSCORE_PREFIXED_VARIANT_TAG_MAPPINGS)) {
 664                                                         /*
 665                                                          * Check if they match with
 666                                                          * a prepended underscore
 667                                                          * and, if not, perform the
 668                                                          * regular check.
 669                                                          */
 670                                                         if ((std::string("_") + field->name) ==
 671                                                             mapping.name) {
 672                                                                 return true;
 673                                                         }
 674                                                 }
 675
 676                                                 return mapping.name == field->name;
 677                                         });
 678
 679                                 if (mapping_it == typed_enumeration.mappings_->end()) {
 680                                         LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 681                                                 "Invalid variant choice: `{}` does not match any mapping in `{}` enumeration",
 682                                                 field->name,
 683                                                 selector_field.name));
 684                                 }
 685
 686                                 choices.emplace_back(*mapping_it, field->move_type());
 687                         },
 688                         lookup_field,
 689                         lookup_root,
 690                         current_field_location_elements,
 691                         quirks);
 692
 693                 current = *next_ust_ctl_field;
 694         }
 695
 696         return choices;
 697 }
 698
 699 lst::type::cuptr create_variant_field_from_ust_ctl_fields(
 700         const lttng_ust_ctl_field *current,
 701         const lttng_ust_ctl_field *end,
 702         const session_attributes& session_attributes,
 703         const lttng_ust_ctl_field **next_ust_ctl_field,
 704         const lookup_field_fn& lookup_field,
 705         lst::field_location::root lookup_root,
 706         lst::field_location::elements& current_field_location_elements,
 707         lsu::ctl_field_quirks quirks)
 708 {
 709         if (current >= end) {
 710                 LTTNG_THROW_PROTOCOL_ERROR(lttng::format(
 711                         "End of {} array reached unexpectedly during decoding", typeid(*current)));
 712         }
 713
 714         const auto& variant_uctl_field = *current;
 715         current++;
 716
 717         uint32_t alignment;
 718         uint32_t choice_count;
 719         const char *tag_name;
 720
 721         if (variant_uctl_field.type.atype == lttng_ust_ctl_atype_variant) {
 722                 alignment = 0;
 723                 choice_count = variant_uctl_field.type.u.legacy.variant.nr_choices;
 724                 tag_name = variant_uctl_field.type.u.legacy.variant.tag_name;
 725         } else {
 726                 alignment = variant_uctl_field.type.u.variant_nestable.alignment;
 727                 choice_count = variant_uctl_field.type.u.variant_nestable.nr_choices;
 728                 tag_name = variant_uctl_field.type.u.variant_nestable.tag_name;
 729         }
 730
 731         lst::field_location::elements selector_field_location_elements =
 732                 current_field_location_elements;
 733         selector_field_location_elements.emplace_back(tag_name);
 734
 735         lst::field_location selector_field_location{ lookup_root,
 736                                                      std::move(selector_field_location_elements) };
 737
 738         /* Validate existence of selector field (throws if not found). */
 739         const auto& selector_field = lookup_field(selector_field_location);
 740         const auto *enumeration_selector_type =
 741                 dynamic_cast<const lst::enumeration_type *>(&selector_field.get_type());
 742         if (!enumeration_selector_type) {
 743                 LTTNG_THROW_PROTOCOL_ERROR(
 744                         "Invalid selector field type referenced from variant: expected enumeration");
 745         }
 746
 747         const bool selector_is_signed = enumeration_selector_type->signedness_ ==
 748                 lst::integer_type::signedness::SIGNED;
 749
 750         /* Choices follow. next_ust_ctl_field is updated as needed. */
 751         if (selector_is_signed) {
 752                 lst::variant_type<lst::signed_enumeration_type::mapping::range_t::range_integer_t>::
 753                         choices choices = create_typed_variant_choices<int64_t>(
 754                                 current,
 755                                 end,
 756                                 session_attributes,
 757                                 next_ust_ctl_field,
 758                                 lookup_field,
 759                                 lookup_root,
 760                                 current_field_location_elements,
 761                                 choice_count,
 762                                 selector_field,
 763                                 quirks);
 764
 765                 return lttng::make_unique<lst::variant_type<int64_t>>(
 766                         alignment, std::move(selector_field_location), std::move(choices));
 767         } else {
 768                 lst::variant_type<
 769                         lst::unsigned_enumeration_type::mapping::range_t::range_integer_t>::choices
 770                         choices = create_typed_variant_choices<uint64_t>(
 771                                 current,
 772                                 end,
 773                                 session_attributes,
 774                                 next_ust_ctl_field,
 775                                 lookup_field,
 776                                 lookup_root,
 777                                 current_field_location_elements,
 778                                 choice_count,
 779                                 selector_field,
 780                                 quirks);
 781
 782                 return lttng::make_unique<lst::variant_type<uint64_t>>(
 783                         alignment, std::move(selector_field_location), std::move(choices));
 784         }
 785 }
 786
 787 lst::type::cuptr
 788 create_type_from_ust_ctl_fields(const lttng_ust_ctl_field *current,
 789                                 const lttng_ust_ctl_field *end,
 790                                 const session_attributes& session_attributes,
 791                                 const lttng_ust_ctl_field **next_ust_ctl_field,
 792                                 const publish_field_fn& publish_field,
 793                                 const lookup_field_fn& lookup_field,
 794                                 lst::field_location::root lookup_root,
 795                                 lst::field_location::elements& current_field_location_elements,
 796                                 lsu::ctl_field_quirks quirks)
 797 {
 798         switch (current->type.atype) {
 799         case lttng_ust_ctl_atype_integer:
 800                 return create_integer_type_from_ust_ctl_fields(
 801                         current, end, session_attributes, next_ust_ctl_field, quirks);
 802         case lttng_ust_ctl_atype_enum:
 803         case lttng_ust_ctl_atype_enum_nestable:
 804                 return create_enumeration_type_from_ust_ctl_fields(
 805                         current, end, session_attributes, next_ust_ctl_field, quirks);
 806         case lttng_ust_ctl_atype_float:
 807                 return create_floating_point_type_from_ust_ctl_fields(
 808                         current, end, session_attributes, next_ust_ctl_field, quirks);
 809         case lttng_ust_ctl_atype_string:
 810                 return create_string_type_from_ust_ctl_fields(
 811                         current, end, session_attributes, next_ust_ctl_field, quirks);
 812         case lttng_ust_ctl_atype_array:
 813                 return create_array_type_from_ust_ctl_fields(
 814                         current, end, session_attributes, next_ust_ctl_field, quirks);
 815         case lttng_ust_ctl_atype_array_nestable:
 816                 return create_array_nestable_type_from_ust_ctl_fields(
 817                         current,
 818                         end,
 819                         session_attributes,
 820                         next_ust_ctl_field,
 821                         publish_field,
 822                         lookup_field,
 823                         lookup_root,
 824                         current_field_location_elements,
 825                         quirks);
 826         case lttng_ust_ctl_atype_sequence:
 827                 return create_sequence_type_from_ust_ctl_fields(current,
 828                                                                 end,
 829                                                                 session_attributes,
 830                                                                 next_ust_ctl_field,
 831                                                                 publish_field,
 832                                                                 lookup_root,
 833                                                                 current_field_location_elements,
 834                                                                 quirks);
 835         case lttng_ust_ctl_atype_sequence_nestable:
 836                 return create_sequence_nestable_type_from_ust_ctl_fields(
 837                         current,
 838                         end,
 839                         session_attributes,
 840                         next_ust_ctl_field,
 841                         publish_field,
 842                         lookup_field,
 843                         lookup_root,
 844                         current_field_location_elements,
 845                         quirks);
 846         case lttng_ust_ctl_atype_struct:
 847         case lttng_ust_ctl_atype_struct_nestable:
 848                 return create_structure_field_from_ust_ctl_fields(
 849                         current, end, session_attributes, next_ust_ctl_field, quirks);
 850         case lttng_ust_ctl_atype_variant:
 851         case lttng_ust_ctl_atype_variant_nestable:
 852                 return create_variant_field_from_ust_ctl_fields(current,
 853                                                                 end,
 854                                                                 session_attributes,
 855                                                                 next_ust_ctl_field,
 856                                                                 lookup_field,
 857                                                                 lookup_root,
 858                                                                 current_field_location_elements,
 859                                                                 quirks);
 860         default:
 861                 LTTNG_THROW_PROTOCOL_ERROR(
 862                         lttng::format("Unknown {} value `{}` encountered while converting {} to {}",
 863                                       typeid(current->type.atype),
 864                                       current->type.atype,
 865                                       typeid(*current),
 866                                       typeid(lst::type::cuptr::element_type)));
 867         }
 868 }
 869
 870 void create_field_from_ust_ctl_fields(const lttng_ust_ctl_field *current,
 871                                       const lttng_ust_ctl_field *end,
 872                                       const session_attributes& session_attributes,
 873                                       const lttng_ust_ctl_field **next_ust_ctl_field,
 874                                       const publish_field_fn& publish_field,
 875                                       const lookup_field_fn& lookup_field,
 876                                       lst::field_location::root lookup_root,
 877                                       lst::field_location::elements& current_field_location_elements,
 878                                       lsu::ctl_field_quirks quirks)
 879 {
 880         LTTNG_ASSERT(current < end);
 881
 882         if (lttng_strnlen(current->name, sizeof(current->name)) == sizeof(current->name)) {
 883                 LTTNG_THROW_PROTOCOL_ERROR(
 884                         lttng::format("Name of {} is not null-terminated", typeid(*current)));
 885         }
 886
 887         publish_field(lttng::make_unique<lst::field>(
 888                 current->name,
 889                 create_type_from_ust_ctl_fields(current,
 890                                                 end,
 891                                                 session_attributes,
 892                                                 next_ust_ctl_field,
 893                                                 publish_field,
 894                                                 lookup_field,
 895                                                 lookup_root,
 896                                                 current_field_location_elements,
 897                                                 quirks)));
 898 }
 899
 900 std::vector<lst::field::cuptr>::iterator
 901 lookup_field_in_vector(std::vector<lst::field::cuptr>& fields, const lst::field_location& location)
 902 {
 903         if (location.elements_.size() != 1) {
 904                 LTTNG_THROW_ERROR(lttng::format(
 905                         "Unexpected field location received during field look-up: location = {}",
 906                         location));
 907         }
 908
 909         /*
 910          * In the context of fields received from LTTng-UST, field
 911          * look-up is extremely naive as the protocol can only
 912          * express empty structures. It is safe to assume that
 913          * location has a depth of 1 and directly refers to a field
 914          * in the 'fields' vector.
 915          */
 916         const auto field_it =
 917                 std::find_if(fields.begin(), fields.end(), [location](lst::field::cuptr& field) {
 918                         return field->name == location.elements_[0];
 919                 });
 920
 921         if (field_it == fields.end()) {
 922                 LTTNG_THROW_PROTOCOL_ERROR(
 923                         lttng::format("Failed to look-up field: location = {}", location));
 924         }
 925
 926         return field_it;
 927 }
 928
 929 /*
 930  * `lttng_ust_ctl_field`s can be nested, in which case creating a field will consume
 931  * more than one lttng_ust_ctl_field. create_field_from_ust_ctl_fields returns the
 932  * position of the next lttng_ust_ctl_field to consume or `end` when the last field
 933  * is consumed.
 934  *
 935  * Always returns a new field, throws on error.
 936  */
 937 std::vector<lst::field::cuptr>
 938 create_fields_from_ust_ctl_fields(const lsu::registry_session& session,
 939                                   const lttng_ust_ctl_field *current,
 940                                   const lttng_ust_ctl_field *end,
 941                                   lst::field_location::root lookup_root,
 942                                   lsu::ctl_field_quirks quirks)
 943 {
 944         std::vector<lst::field::cuptr> fields;
 945         const auto trace_native_byte_order = session.abi.byte_order;
 946         const session_attributes session_attributes{
 947                 [&session](const char *enum_name, uint64_t enum_id) {
 948                         return session.enumeration(enum_name, enum_id);
 949                 },
 950                 trace_native_byte_order
 951         };
 952         /* Location of field being created. */
 953         lst::field_location::elements current_field_location_elements;
 954
 955         while (current < end) {
 956                 auto *next_field = current;
 957
 958                 /*
 959                  * create_field_from_ust_ctl_fields will consume one field at a time.
 960                  * However, some fields expressed by LTTng-UST's protocol are expended
 961                  * to multiple event fields (legacy sequence fields implicitly define
 962                  * their length field).
 963                  *
 964                  * The lambda allows the factory functions to push as many fields as
 965                  * needed depending on the decoded field's type.
 966                  */
 967                 create_field_from_ust_ctl_fields(
 968                         current,
 969                         end,
 970                         session_attributes,
 971                         &next_field,
 972                         [&fields](lst::field::cuptr field) {
 973                                 /* Publishing a field simply adds it to the converted
 974                                  * fields. */
 975                                 fields.emplace_back(std::move(field));
 976                         },
 977                         [&fields](const lst::field_location& location)
 978                                 -> lookup_field_fn::result_type {
 979                                 /* Resolve location to a previously-constructed field. */
 980                                 return **lookup_field_in_vector(fields, location);
 981                         },
 982                         lookup_root,
 983                         current_field_location_elements,
 984                         quirks);
 985
 986                 current = next_field;
 987         }
 988
 989         return fields;
 990 }
 991 } /* namespace */
 992
 993 std::vector<lst::field::cuptr>
 994 lsu::create_trace_fields_from_ust_ctl_fields(const lsu::registry_session& session,
 995                                              const lttng_ust_ctl_field *fields,
 996                                              std::size_t field_count,
 997                                              lst::field_location::root lookup_root,
 998                                              lsu::ctl_field_quirks quirks)
 999 {
1000         return create_fields_from_ust_ctl_fields(
1001                 session, fields, fields + field_count, lookup_root, quirks);
1002 }