Merge "PDL: Add ParentDef for packets" (2b4474d2) · Commits · e / os / android_packages_modules_Bluetooth

system/gd/packet/parser/Android.bp

+1 −0

Original line number	Diff line number	Diff line
		@@ -19,6 +19,7 @@ cc_binary_host {
		"enum_def.cc",
		"enum_gen.cc",
		"packet_def.cc",
		"parent_def.cc",
		"main.cc",
		"language_y.yy",
		"language_l.ll",

system/gd/packet/parser/packet_def.cc

+9 −202

Original line number	Diff line number	Diff line
		@@ -22,177 +22,11 @@
		#include "fields/all_fields.h"
		#include "util.h"

		PacketDef::PacketDef(std::string name, FieldList fields) : name_(name), fields_(fields), parent_(nullptr){};
		PacketDef::PacketDef(std::string name, FieldList fields, PacketDef* parent)
		: name_(name), fields_(fields), parent_(parent){};
		PacketDef::PacketDef(std::string name, FieldList fields) : ParentDef(name, fields, nullptr){};
		PacketDef::PacketDef(std::string name, FieldList fields, PacketDef* parent) : ParentDef(name, fields, parent){};

		void PacketDef::AddParentConstraint(std::string field_name, std::variant<int64_t, std::string> value) {
		// NOTE: This could end up being very slow if there are a lot of constraints.
		const auto& parent_params = parent_->GetParamList();
		const auto& constrained_field = parent_params.GetField(field_name);
		if (constrained_field == nullptr) {
		ERROR() << "Attempting to constrain field " << field_name << " in parent packet " << parent_->name_
		<< ", but no such field exists.";
		}

		if (constrained_field->GetFieldType() == PacketField::Type::SCALAR) {
		if (!std::holds_alternative<int64_t>(value)) {
		ERROR(constrained_field) << "Attemting to constrain a scalar field using an enum value in packet "
		<< parent_->name_ << ".";
		}
		} else if (constrained_field->GetFieldType() == PacketField::Type::ENUM) {
		if (!std::holds_alternative<std::string>(value)) {
		ERROR(constrained_field) << "Attemting to constrain an enum field using an scalar value in packet "
		<< parent_->name_ << ".";
		}
		const auto& enum_def = static_cast<EnumField*>(constrained_field)->GetEnumDef();
		if (!enum_def.HasEntry(std::get<std::string>(value))) {
		ERROR(constrained_field) << "No matching enumeration \"" << std::get<std::string>(value)
		<< "\" for constraint on enum in parent packet " << parent_->name_ << ".";
		}

		// For enums, we have to qualify the value using the enum type name.
		value = enum_def.GetTypeName() + "::" + std::get<std::string>(value);
		} else {
		ERROR(constrained_field) << "Field in parent packet " << parent_->name_ << " is not viable for constraining.";
		}

		parent_constraints_.insert(std::pair(field_name, value));
		}

		// Assign all size fields to their corresponding variable length fields.
		// Will crash if
		// - there aren't any fields that don't match up to a field.
		// - the size field points to a fixed size field.
		// - if the size field comes after the variable length field.
		void PacketDef::AssignSizeFields() {
		for (const auto& field : fields_) {
		DEBUG() << "field name: " << field->GetName();

		if (field->GetFieldType() != PacketField::Type::SIZE && field->GetFieldType() != PacketField::Type::COUNT) {
		continue;
		}

		const SizeField* size_field = nullptr;
		size_field = static_cast<SizeField*>(field);
		// Check to see if a corresponding field can be found.
		const auto& var_len_field = fields_.GetField(size_field->GetSizedFieldName());
		if (var_len_field == nullptr) {
		ERROR(field) << "Could not find corresponding field for size/count field.";
		}

		// Do the ordering check to ensure the size field comes before the
		// variable length field.
		for (auto it = fields_.begin(); *it != size_field; it++) {
		DEBUG() << "field name: " << (*it)->GetName();
		if (*it == var_len_field) {
		ERROR(var_len_field, size_field) << "Size/count field must come before the variable length field it describes.";
		}
		}

		if (var_len_field->GetFieldType() == PacketField::Type::PAYLOAD) {
		const auto& payload_field = static_cast<PayloadField*>(var_len_field);
		payload_field->SetSizeField(size_field);
		continue;
		}

		if (var_len_field->GetFieldType() == PacketField::Type::ARRAY) {
		const auto& array_field = static_cast<ArrayField*>(var_len_field);
		array_field->SetSizeField(size_field);
		continue;
		}

		// TODO: If there is an array field without a size field, check to see if the
		// parent has a size(payload) field. Or maybe we can just figure it out based
		// on the offsets fo the packet.

		// If we've reached this point then the field wasn't a variable length field.
		// Check to see if the field is a variable length field
		std::cerr << "Can not use size/count in reference to a fixed size field.\n";
		abort();
		}
		}

		void PacketDef::SetEndianness(bool is_little_endian) {
		is_little_endian_ = is_little_endian;
		}

		// Get the size for the packet. You scan specify without_payload in order
		// to exclude payload fields as child packets will be overriding it.
		Size PacketDef::GetSize(bool without_payload) const {
		auto size = Size();

		for (const auto& field : fields_) {
		if (without_payload && field->GetFieldType() == PacketField::Type::PAYLOAD) {
		continue;
		}

		size += field->GetSize();
		}

		if (parent_ != nullptr) {
		size += parent_->GetSize(true);
		}

		return size;
		}

		// Get the offset until the field is reached, if there is no field
		// returns an empty Size. from_end requests the offset to the field
		// starting from the end() iterator. If there is a field with an unknown
		// size along the traversal, then an empty size is returned.
		Size PacketDef::GetOffsetForField(std::string field_name, bool from_end) const {
		// Check first if the field exists.
		if (fields_.GetField(field_name) == nullptr) {
		if (field_name != "payload" && field_name != "body") {
		ERROR() << "Can't find a field offset for nonexistent field named: " << field_name;
		} else {
		return Size();
		}
		}

		// We have to use a generic lambda to conditionally change iteration direction
		// due to iterator and reverse_iterator being different types.
		auto size_lambda = [&](auto from, auto to) -> Size {
		auto size = Size(0);
		for (auto it = from; it != to; it++) {
		// We've reached the field, end the loop.
		if ((*it)->GetName() == field_name) break;
		const auto& field = *it;
		// If there was a field that wasn't the payload with an unknown size,
		// return an empty Size.
		if (field->GetSize().empty()) {
		return Size();
		}
		size += field->GetSize();
		}
		return size;
		};

		// Change iteration direction based on from_end.
		auto size = Size();
		if (from_end)
		size = size_lambda(fields_.rbegin(), fields_.rend());
		else
		size = size_lambda(fields_.begin(), fields_.end());
		if (size.empty()) return Size();

		// For parent packets we need the offset until a payload or body field.
		if (parent_ != nullptr) {
		auto parent_payload_offset = parent_->GetOffsetForField("payload", from_end);
		if (!parent_payload_offset.empty()) {
		size += parent_payload_offset;
		} else {
		parent_payload_offset = parent_->GetOffsetForField("body", from_end);
		if (!parent_payload_offset.empty()) {
		size += parent_payload_offset;
		} else {
		return Size();
		}
		}
		}

		return size;
		PacketField* PacketDef::GetNewField(const std::string&, ParseLocation) const {
		return nullptr; // Packets can't be fields
		}

		void PacketDef::GenParserDefinition(std::ostream& s) const {
		@@ -410,6 +244,10 @@ void PacketDef::GenBuilderSize(std::ostream& s) const {
		s << "}\n";
		}

		TypeDef::Type PacketDef::GetDefinitionType() const {
		return TypeDef::Type::PACKET;
		}

		void PacketDef::GenValidator(std::ostream& s) const {
		// Get the static offset for all of our fields.
		int bits_size = 0;
		@@ -589,32 +427,10 @@ void PacketDef::GenBuilderDefinition(std::ostream& s) const {
		GenBuilderParameterChecker(s);
		s << "\n";

		GenBuilderMembers(s);
		GenMembers(s);
		s << "};\n";
		}

		FieldList PacketDef::GetParamList() const {
		FieldList params;

		std::set<PacketField::Type> param_types = {
		PacketField::Type::SCALAR, PacketField::Type::ENUM, PacketField::Type::ARRAY,
		PacketField::Type::CUSTOM, PacketField::Type::BODY, PacketField::Type::PAYLOAD,
		};

		if (parent_ != nullptr) {
		auto parent_params = parent_->GetParamList().GetFieldsWithTypes(param_types);

		// Do not include constrained fields in the params
		for (const auto& field : parent_params) {
		if (parent_constraints_.find(field->GetName()) == parent_constraints_.end()) {
		params.AppendField(field);
		}
		}
		}
		// Add the parameters for this packet.
		return params.Merge(fields_.GetFieldsWithTypes(param_types));
		}

		FieldList PacketDef::GetParametersToValidate() const {
		FieldList params_to_validate;
		for (const auto& field : GetParamList()) {
		@@ -771,12 +587,3 @@ void PacketDef::GenBuilderConstructor(std::ostream& s) const {

		s << "}\n";
		}

		void PacketDef::GenBuilderMembers(std::ostream& s) const {
		// Add the parameter list.
		for (int i = 0; i < fields_.size(); i++) {
		if (fields_[i]->GenBuilderParameter(s)) {
		s << "_;";
		}
		}
		}

system/gd/packet/parser/packet_def.h

+5 −36

Original line number	Diff line number	Diff line
		@@ -22,32 +22,14 @@
		#include "enum_def.h"
		#include "field_list.h"
		#include "fields/packet_field.h"
		#include "parent_def.h"

		class PacketDef {
		class PacketDef : public ParentDef {
		public:
		PacketDef(std::string name, FieldList fields);
		PacketDef(std::string name, FieldList fields, PacketDef* parent);

		void AddParentConstraint(std::string field_name, std::variant<int64_t, std::string> value);

		// Assign all size fields to their corresponding variable length fields.
		// Will crash if
		// - there aren't any fields that don't match up to a field.
		// - the size field points to a fixed size field.
		// - if the size field comes after the variable length field.
		void AssignSizeFields();

		void SetEndianness(bool is_little_endian);

		// Get the size for the packet. You scan specify without_payload in order
		// to exclude payload fields as child packets will be overriding it.
		Size GetSize(bool without_payload = false) const;

		// Get the offset until the field is reached, if there is no field
		// returns an empty Size. from_end requests the offset to the field
		// starting from the end() iterator. If there is a field with an unknown
		// size along the traversal, then an empty size is returned.
		Size GetOffsetForField(std::string field_name, bool from_end = false) const;
		PacketField* GetNewField(const std::string& name, ParseLocation loc) const;

		void GenParserDefinition(std::ostream& s) const;

		@@ -59,9 +41,9 @@ class PacketDef {

		void GenValidator(std::ostream& s) const;

		void GenBuilderDefinition(std::ostream& s) const;
		TypeDef::Type GetDefinitionType() const;

		FieldList GetParamList() const;
		void GenBuilderDefinition(std::ostream& s) const;

		FieldList GetParametersToValidate() const;

		@@ -70,17 +52,4 @@ class PacketDef {
		void GenBuilderParameterChecker(std::ostream& s) const;

		void GenBuilderConstructor(std::ostream& s) const;

		void GenBuilderMembers(std::ostream& s) const;

		std::string name_;
		FieldList fields_;

		std::variant<std::monostate, std::string, EnumDef*> specialize_on_;
		std::variant<std::monostate, int, std::string> specialization_value_;

		PacketDef* parent_; // Parent packet type

		std::map<std::string, std::variant<int64_t, std::string>> parent_constraints_;
		bool is_little_endian_;
		};

system/gd/packet/parser/parent_def.cc

0 → 100644

+243 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright 2019 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		#include "parent_def.h"

		#include "fields/all_fields.h"
		#include "util.h"

		ParentDef::ParentDef(std::string name, FieldList fields) : TypeDef(name), fields_(fields), parent_(nullptr){};
		ParentDef::ParentDef(std::string name, FieldList fields, ParentDef* parent)
		: TypeDef(name), fields_(fields), parent_(parent){};

		void ParentDef::AddParentConstraint(std::string field_name, std::variant<int64_t, std::string> value) {
		// NOTE: This could end up being very slow if there are a lot of constraints.
		const auto& parent_params = parent_->GetParamList();
		const auto& constrained_field = parent_params.GetField(field_name);
		if (constrained_field == nullptr) {
		ERROR() << "Attempting to constrain field " << field_name << " in parent " << parent_->name_
		<< ", but no such field exists.";
		}

		if (constrained_field->GetFieldType() == PacketField::Type::SCALAR) {
		if (!std::holds_alternative<int64_t>(value)) {
		ERROR(constrained_field) << "Attemting to constrain a scalar field to an enum value in " << parent_->name_;
		}
		} else if (constrained_field->GetFieldType() == PacketField::Type::ENUM) {
		if (!std::holds_alternative<std::string>(value)) {
		ERROR(constrained_field) << "Attemting to constrain an enum field to a scalar value in " << parent_->name_;
		}
		const auto& enum_def = static_cast<EnumField*>(constrained_field)->GetEnumDef();
		if (!enum_def.HasEntry(std::get<std::string>(value))) {
		ERROR(constrained_field) << "No matching enumeration \"" << std::get<std::string>(value)
		<< "for constraint on enum in parent " << parent_->name_ << ".";
		}

		// For enums, we have to qualify the value using the enum type name.
		value = enum_def.GetTypeName() + "::" + std::get<std::string>(value);
		} else {
		ERROR(constrained_field) << "Field in parent " << parent_->name_ << " is not viable for constraining.";
		}

		parent_constraints_.insert(std::pair(field_name, value));
		}

		// Assign all size fields to their corresponding variable length fields.
		// Will crash if
		// - there aren't any fields that don't match up to a field.
		// - the size field points to a fixed size field.
		// - if the size field comes after the variable length field.
		void ParentDef::AssignSizeFields() {
		for (const auto& field : fields_) {
		DEBUG() << "field name: " << field->GetName();

		if (field->GetFieldType() != PacketField::Type::SIZE && field->GetFieldType() != PacketField::Type::COUNT) {
		continue;
		}

		const SizeField* size_field = static_cast<SizeField*>(field);
		// Check to see if a corresponding field can be found.
		const auto& var_len_field = fields_.GetField(size_field->GetSizedFieldName());
		if (var_len_field == nullptr) {
		ERROR(field) << "Could not find corresponding field for size/count field.";
		}

		// Do the ordering check to ensure the size field comes before the
		// variable length field.
		for (auto it = fields_.begin(); *it != size_field; it++) {
		DEBUG() << "field name: " << (*it)->GetName();
		if (*it == var_len_field) {
		ERROR(var_len_field, size_field) << "Size/count field must come before the variable length field it describes.";
		}
		}

		if (var_len_field->GetFieldType() == PacketField::Type::PAYLOAD) {
		const auto& payload_field = static_cast<PayloadField*>(var_len_field);
		payload_field->SetSizeField(size_field);
		continue;
		}

		if (var_len_field->GetFieldType() == PacketField::Type::ARRAY) {
		const auto& array_field = static_cast<ArrayField*>(var_len_field);
		array_field->SetSizeField(size_field);
		continue;
		}

		// If we've reached this point then the field wasn't a variable length field.
		// Check to see if the field is a variable length field
		std::cerr << "Can not use size/count in reference to a fixed size field.\n";
		abort();
		}
		}

		void ParentDef::SetEndianness(bool is_little_endian) {
		is_little_endian_ = is_little_endian;
		}

		// Get the size. You scan specify without_payload in order to exclude payload fields as children will be overriding it.
		Size ParentDef::GetSize(bool without_payload) const {
		auto size = Size();

		for (const auto& field : fields_) {
		if (without_payload &&
		(field->GetFieldType() == PacketField::Type::PAYLOAD \|\| field->GetFieldType() == PacketField::Type::BODY)) {
		continue;
		}

		// The offset to the field must be passed in as an argument for dynamically sized custom fields.
		if (field->GetFieldType() == PacketField::Type::CUSTOM && field->GetSize().has_dynamic()) {
		std::stringstream custom_field_size;

		// Custom fields are special as their size field takes an argument.
		custom_field_size << field->GetSize().dynamic_string() << "(begin()";

		// Check if we can determine offset from begin(), otherwise error because by this point,
		// the size of the custom field is unknown and can't be subtracted from end() to get the
		// offset.
		auto offset = GetOffsetForField(field->GetName(), false);
		if (offset.empty()) {
		ERROR(field) << "Custom Field offset can not be determined from begin().";
		}

		if (offset.bits() % 8 != 0) {
		ERROR(field) << "Custom fields must be byte aligned.";
		}
		if (offset.has_bits()) custom_field_size << " + " << offset.bits() / 8;
		if (offset.has_dynamic()) custom_field_size << " + " << offset.dynamic_string();
		custom_field_size << ")";

		size += custom_field_size.str();
		continue;
		}

		size += field->GetSize();
		}

		if (parent_ != nullptr) {
		size += parent_->GetSize(true);
		}

		return size;
		}

		// Get the offset until the field is reached, if there is no field
		// returns an empty Size. from_end requests the offset to the field
		// starting from the end() iterator. If there is a field with an unknown
		// size along the traversal, then an empty size is returned.
		Size ParentDef::GetOffsetForField(std::string field_name, bool from_end) const {
		// Check first if the field exists.
		if (fields_.GetField(field_name) == nullptr) {
		if (field_name != "payload" && field_name != "body") {
		ERROR() << "Can't find a field offset for nonexistent field named: " << field_name;
		} else {
		return Size();
		}
		}

		// We have to use a generic lambda to conditionally change iteration direction
		// due to iterator and reverse_iterator being different types.
		auto size_lambda = [&](auto from, auto to) -> Size {
		auto size = Size(0);
		for (auto it = from; it != to; it++) {
		// We've reached the field, end the loop.
		if ((*it)->GetName() == field_name) break;
		const auto& field = *it;
		// If there was a field that wasn't the payload with an unknown size,
		// return an empty Size.
		if (field->GetSize().empty()) {
		return Size();
		}
		size += field->GetSize();
		}
		return size;
		};

		// Change iteration direction based on from_end.
		auto size = Size();
		if (from_end)
		size = size_lambda(fields_.rbegin(), fields_.rend());
		else
		size = size_lambda(fields_.begin(), fields_.end());
		if (size.empty()) return Size();

		// We need the offset until a payload or body field.
		if (parent_ != nullptr) {
		auto parent_payload_offset = parent_->GetOffsetForField("payload", from_end);
		if (!parent_payload_offset.empty()) {
		size += parent_payload_offset;
		} else {
		parent_payload_offset = parent_->GetOffsetForField("body", from_end);
		if (!parent_payload_offset.empty()) {
		size += parent_payload_offset;
		} else {
		return Size();
		}
		}
		}

		return size;
		}

		FieldList ParentDef::GetParamList() const {
		FieldList params;

		std::set<PacketField::Type> param_types = {
		PacketField::Type::SCALAR, PacketField::Type::ENUM, PacketField::Type::ARRAY,
		PacketField::Type::CUSTOM, PacketField::Type::BODY, PacketField::Type::PAYLOAD,
		};

		if (parent_ != nullptr) {
		auto parent_params = parent_->GetParamList().GetFieldsWithTypes(param_types);

		// Do not include constrained fields in the params
		for (const auto& field : parent_params) {
		if (parent_constraints_.find(field->GetName()) == parent_constraints_.end()) {
		params.AppendField(field);
		}
		}
		}
		// Add our parameters.
		return params.Merge(fields_.GetFieldsWithTypes(param_types));
		}

		void ParentDef::GenMembers(std::ostream& s) const {
		// Add the parameter list.
		for (int i = 0; i < fields_.size(); i++) {
		if (fields_[i]->GenBuilderParameter(s)) {
		s << "_;";
		}
		}
		}

system/gd/packet/parser/parent_def.h

0 → 100644

+64 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright 2019 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		#pragma once

		#include <map>
		#include <variant>

		#include "enum_def.h"
		#include "field_list.h"
		#include "fields/all_fields.h"
		#include "fields/packet_field.h"
		#include "parse_location.h"
		#include "type_def.h"

		class ParentDef : public TypeDef {
		public:
		ParentDef(std::string name, FieldList fields);
		ParentDef(std::string name, FieldList fields, ParentDef* parent);

		void AddParentConstraint(std::string field_name, std::variant<int64_t, std::string> value);

		// Assign all size fields to their corresponding variable length fields.
		// Will crash if
		// - there aren't any fields that don't match up to a field.
		// - the size field points to a fixed size field.
		// - if the size field comes after the variable length field.
		void AssignSizeFields();

		void SetEndianness(bool is_little_endian);

		// Get the size. You scan specify without_payload to exclude payload and body fields as children override them.
		Size GetSize(bool without_payload = false) const;

		// Get the offset until the field is reached, if there is no field
		// returns an empty Size. from_end requests the offset to the field
		// starting from the end() iterator. If there is a field with an unknown
		// size along the traversal, then an empty size is returned.
		Size GetOffsetForField(std::string field_name, bool from_end = false) const;

		FieldList GetParamList() const;

		void GenMembers(std::ostream& s) const;

		FieldList fields_;

		ParentDef* parent_{nullptr};

		std::map<std::string, std::variant<int64_t, std::string>> parent_constraints_;
		bool is_little_endian_;
		};