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Diffstat (limited to 'tools/inspector_protocol/lib/encoding_cpp.template')
| -rw-r--r-- | tools/inspector_protocol/lib/encoding_cpp.template | 2199 |
1 files changed, 2199 insertions, 0 deletions
diff --git a/tools/inspector_protocol/lib/encoding_cpp.template b/tools/inspector_protocol/lib/encoding_cpp.template new file mode 100644 index 0000000000..54a46ecd20 --- /dev/null +++ b/tools/inspector_protocol/lib/encoding_cpp.template @@ -0,0 +1,2199 @@ +{# This template is generated by gen_cbor_templates.py. #} +// Generated by lib/encoding_cpp.template. + +// Copyright 2019 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + + +#include <algorithm> +#include <cassert> +#include <cmath> +#include <cstring> +#include <limits> +#include <stack> + +{% for namespace in config.protocol.namespace %} +namespace {{namespace}} { +{% endfor %} + +// ===== encoding/encoding.cc ===== + +// ============================================================================= +// Status and Error codes +// ============================================================================= + +std::string Status::ToASCIIString() const { + switch (error) { + case Error::OK: + return "OK"; + case Error::JSON_PARSER_UNPROCESSED_INPUT_REMAINS: + return ToASCIIString("JSON: unprocessed input remains"); + case Error::JSON_PARSER_STACK_LIMIT_EXCEEDED: + return ToASCIIString("JSON: stack limit exceeded"); + case Error::JSON_PARSER_NO_INPUT: + return ToASCIIString("JSON: no input"); + case Error::JSON_PARSER_INVALID_TOKEN: + return ToASCIIString("JSON: invalid token"); + case Error::JSON_PARSER_INVALID_NUMBER: + return ToASCIIString("JSON: invalid number"); + case Error::JSON_PARSER_INVALID_STRING: + return ToASCIIString("JSON: invalid string"); + case Error::JSON_PARSER_UNEXPECTED_ARRAY_END: + return ToASCIIString("JSON: unexpected array end"); + case Error::JSON_PARSER_COMMA_OR_ARRAY_END_EXPECTED: + return ToASCIIString("JSON: comma or array end expected"); + case Error::JSON_PARSER_STRING_LITERAL_EXPECTED: + return ToASCIIString("JSON: string literal expected"); + case Error::JSON_PARSER_COLON_EXPECTED: + return ToASCIIString("JSON: colon expected"); + case Error::JSON_PARSER_UNEXPECTED_MAP_END: + return ToASCIIString("JSON: unexpected map end"); + case Error::JSON_PARSER_COMMA_OR_MAP_END_EXPECTED: + return ToASCIIString("JSON: comma or map end expected"); + case Error::JSON_PARSER_VALUE_EXPECTED: + return ToASCIIString("JSON: value expected"); + + case Error::CBOR_INVALID_INT32: + return ToASCIIString("CBOR: invalid int32"); + case Error::CBOR_INVALID_DOUBLE: + return ToASCIIString("CBOR: invalid double"); + case Error::CBOR_INVALID_ENVELOPE: + return ToASCIIString("CBOR: invalid envelope"); + case Error::CBOR_INVALID_STRING8: + return ToASCIIString("CBOR: invalid string8"); + case Error::CBOR_INVALID_STRING16: + return ToASCIIString("CBOR: invalid string16"); + case Error::CBOR_INVALID_BINARY: + return ToASCIIString("CBOR: invalid binary"); + case Error::CBOR_UNSUPPORTED_VALUE: + return ToASCIIString("CBOR: unsupported value"); + case Error::CBOR_NO_INPUT: + return ToASCIIString("CBOR: no input"); + case Error::CBOR_INVALID_START_BYTE: + return ToASCIIString("CBOR: invalid start byte"); + case Error::CBOR_UNEXPECTED_EOF_EXPECTED_VALUE: + return ToASCIIString("CBOR: unexpected eof expected value"); + case Error::CBOR_UNEXPECTED_EOF_IN_ARRAY: + return ToASCIIString("CBOR: unexpected eof in array"); + case Error::CBOR_UNEXPECTED_EOF_IN_MAP: + return ToASCIIString("CBOR: unexpected eof in map"); + case Error::CBOR_INVALID_MAP_KEY: + return ToASCIIString("CBOR: invalid map key"); + case Error::CBOR_STACK_LIMIT_EXCEEDED: + return ToASCIIString("CBOR: stack limit exceeded"); + case Error::CBOR_TRAILING_JUNK: + return ToASCIIString("CBOR: trailing junk"); + case Error::CBOR_MAP_START_EXPECTED: + return ToASCIIString("CBOR: map start expected"); + case Error::CBOR_MAP_STOP_EXPECTED: + return ToASCIIString("CBOR: map stop expected"); + case Error::CBOR_ENVELOPE_SIZE_LIMIT_EXCEEDED: + return ToASCIIString("CBOR: envelope size limit exceeded"); + } + // Some compilers can't figure out that we can't get here. + return "INVALID ERROR CODE"; +} + +std::string Status::ToASCIIString(const char* msg) const { + return std::string(msg) + " at position " + std::to_string(pos); +} + +namespace cbor { +namespace { +// Indicates the number of bits the "initial byte" needs to be shifted to the +// right after applying |kMajorTypeMask| to produce the major type in the +// lowermost bits. +static constexpr uint8_t kMajorTypeBitShift = 5u; +// Mask selecting the low-order 5 bits of the "initial byte", which is where +// the additional information is encoded. +static constexpr uint8_t kAdditionalInformationMask = 0x1f; +// Mask selecting the high-order 3 bits of the "initial byte", which indicates +// the major type of the encoded value. +static constexpr uint8_t kMajorTypeMask = 0xe0; +// Indicates the integer is in the following byte. +static constexpr uint8_t kAdditionalInformation1Byte = 24u; +// Indicates the integer is in the next 2 bytes. +static constexpr uint8_t kAdditionalInformation2Bytes = 25u; +// Indicates the integer is in the next 4 bytes. +static constexpr uint8_t kAdditionalInformation4Bytes = 26u; +// Indicates the integer is in the next 8 bytes. +static constexpr uint8_t kAdditionalInformation8Bytes = 27u; + +// Encodes the initial byte, consisting of the |type| in the first 3 bits +// followed by 5 bits of |additional_info|. +constexpr uint8_t EncodeInitialByte(MajorType type, uint8_t additional_info) { + return (static_cast<uint8_t>(type) << kMajorTypeBitShift) | + (additional_info & kAdditionalInformationMask); +} + +// TAG 24 indicates that what follows is a byte string which is +// encoded in CBOR format. We use this as a wrapper for +// maps and arrays, allowing us to skip them, because the +// byte string carries its size (byte length). +// https://tools.ietf.org/html/rfc7049#section-2.4.4.1 +static constexpr uint8_t kInitialByteForEnvelope = + EncodeInitialByte(MajorType::TAG, 24); +// The initial byte for a byte string with at most 2^32 bytes +// of payload. This is used for envelope encoding, even if +// the byte string is shorter. +static constexpr uint8_t kInitialByteFor32BitLengthByteString = + EncodeInitialByte(MajorType::BYTE_STRING, 26); + +// See RFC 7049 Section 2.2.1, indefinite length arrays / maps have additional +// info = 31. +static constexpr uint8_t kInitialByteIndefiniteLengthArray = + EncodeInitialByte(MajorType::ARRAY, 31); +static constexpr uint8_t kInitialByteIndefiniteLengthMap = + EncodeInitialByte(MajorType::MAP, 31); +// See RFC 7049 Section 2.3, Table 1; this is used for finishing indefinite +// length maps / arrays. +static constexpr uint8_t kStopByte = + EncodeInitialByte(MajorType::SIMPLE_VALUE, 31); + +// See RFC 7049 Section 2.3, Table 2. +static constexpr uint8_t kEncodedTrue = + EncodeInitialByte(MajorType::SIMPLE_VALUE, 21); +static constexpr uint8_t kEncodedFalse = + EncodeInitialByte(MajorType::SIMPLE_VALUE, 20); +static constexpr uint8_t kEncodedNull = + EncodeInitialByte(MajorType::SIMPLE_VALUE, 22); +static constexpr uint8_t kInitialByteForDouble = + EncodeInitialByte(MajorType::SIMPLE_VALUE, 27); + +// See RFC 7049 Table 3 and Section 2.4.4.2. This is used as a prefix for +// arbitrary binary data encoded as BYTE_STRING. +static constexpr uint8_t kExpectedConversionToBase64Tag = + EncodeInitialByte(MajorType::TAG, 22); + +// Writes the bytes for |v| to |out|, starting with the most significant byte. +// See also: https://commandcenter.blogspot.com/2012/04/byte-order-fallacy.html +template <typename T, class C> +void WriteBytesMostSignificantByteFirst(T v, C* out) { + for (int shift_bytes = sizeof(T) - 1; shift_bytes >= 0; --shift_bytes) + out->push_back(0xff & (v >> (shift_bytes * 8))); +} + +// Extracts sizeof(T) bytes from |in| to extract a value of type T +// (e.g. uint64_t, uint32_t, ...), most significant byte first. +// See also: https://commandcenter.blogspot.com/2012/04/byte-order-fallacy.html +template <typename T> +T ReadBytesMostSignificantByteFirst(span<uint8_t> in) { + assert(in.size() >= sizeof(T)); + T result = 0; + for (size_t shift_bytes = 0; shift_bytes < sizeof(T); ++shift_bytes) + result |= T(in[sizeof(T) - 1 - shift_bytes]) << (shift_bytes * 8); + return result; +} +} // namespace + +namespace internals { +// Reads the start of a token with definitive size from |bytes|. +// |type| is the major type as specified in RFC 7049 Section 2.1. +// |value| is the payload (e.g. for MajorType::UNSIGNED) or is the size +// (e.g. for BYTE_STRING). +// If successful, returns the number of bytes read. Otherwise returns -1. +// TODO(johannes): change return type to size_t and use 0 for error. +int8_t ReadTokenStart(span<uint8_t> bytes, MajorType* type, uint64_t* value) { + if (bytes.empty()) + return -1; + uint8_t initial_byte = bytes[0]; + *type = MajorType((initial_byte & kMajorTypeMask) >> kMajorTypeBitShift); + + uint8_t additional_information = initial_byte & kAdditionalInformationMask; + if (additional_information < 24) { + // Values 0-23 are encoded directly into the additional info of the + // initial byte. + *value = additional_information; + return 1; + } + if (additional_information == kAdditionalInformation1Byte) { + // Values 24-255 are encoded with one initial byte, followed by the value. + if (bytes.size() < 2) + return -1; + *value = ReadBytesMostSignificantByteFirst<uint8_t>(bytes.subspan(1)); + return 2; + } + if (additional_information == kAdditionalInformation2Bytes) { + // Values 256-65535: 1 initial byte + 2 bytes payload. + if (bytes.size() < 1 + sizeof(uint16_t)) + return -1; + *value = ReadBytesMostSignificantByteFirst<uint16_t>(bytes.subspan(1)); + return 3; + } + if (additional_information == kAdditionalInformation4Bytes) { + // 32 bit uint: 1 initial byte + 4 bytes payload. + if (bytes.size() < 1 + sizeof(uint32_t)) + return -1; + *value = ReadBytesMostSignificantByteFirst<uint32_t>(bytes.subspan(1)); + return 5; + } + if (additional_information == kAdditionalInformation8Bytes) { + // 64 bit uint: 1 initial byte + 8 bytes payload. + if (bytes.size() < 1 + sizeof(uint64_t)) + return -1; + *value = ReadBytesMostSignificantByteFirst<uint64_t>(bytes.subspan(1)); + return 9; + } + return -1; +} + +// Writes the start of a token with |type|. The |value| may indicate the size, +// or it may be the payload if the value is an unsigned integer. +template <typename C> +void WriteTokenStartTmpl(MajorType type, uint64_t value, C* encoded) { + if (value < 24) { + // Values 0-23 are encoded directly into the additional info of the + // initial byte. + encoded->push_back(EncodeInitialByte(type, /*additional_info=*/value)); + return; + } + if (value <= std::numeric_limits<uint8_t>::max()) { + // Values 24-255 are encoded with one initial byte, followed by the value. + encoded->push_back(EncodeInitialByte(type, kAdditionalInformation1Byte)); + encoded->push_back(value); + return; + } + if (value <= std::numeric_limits<uint16_t>::max()) { + // Values 256-65535: 1 initial byte + 2 bytes payload. + encoded->push_back(EncodeInitialByte(type, kAdditionalInformation2Bytes)); + WriteBytesMostSignificantByteFirst<uint16_t>(value, encoded); + return; + } + if (value <= std::numeric_limits<uint32_t>::max()) { + // 32 bit uint: 1 initial byte + 4 bytes payload. + encoded->push_back(EncodeInitialByte(type, kAdditionalInformation4Bytes)); + WriteBytesMostSignificantByteFirst<uint32_t>(static_cast<uint32_t>(value), + encoded); + return; + } + // 64 bit uint: 1 initial byte + 8 bytes payload. + encoded->push_back(EncodeInitialByte(type, kAdditionalInformation8Bytes)); + WriteBytesMostSignificantByteFirst<uint64_t>(value, encoded); +} +void WriteTokenStart(MajorType type, + uint64_t value, + std::vector<uint8_t>* encoded) { + WriteTokenStartTmpl(type, value, encoded); +} +void WriteTokenStart(MajorType type, uint64_t value, std::string* encoded) { + WriteTokenStartTmpl(type, value, encoded); +} +} // namespace internals + +// ============================================================================= +// Detecting CBOR content +// ============================================================================= + +uint8_t InitialByteForEnvelope() { + return kInitialByteForEnvelope; +} +uint8_t InitialByteFor32BitLengthByteString() { + return kInitialByteFor32BitLengthByteString; +} +bool IsCBORMessage(span<uint8_t> msg) { + return msg.size() >= 6 && msg[0] == InitialByteForEnvelope() && + msg[1] == InitialByteFor32BitLengthByteString(); +} + +// ============================================================================= +// Encoding invidiual CBOR items +// ============================================================================= + +uint8_t EncodeTrue() { + return kEncodedTrue; +} +uint8_t EncodeFalse() { + return kEncodedFalse; +} +uint8_t EncodeNull() { + return kEncodedNull; +} + +uint8_t EncodeIndefiniteLengthArrayStart() { + return kInitialByteIndefiniteLengthArray; +} + +uint8_t EncodeIndefiniteLengthMapStart() { + return kInitialByteIndefiniteLengthMap; +} + +uint8_t EncodeStop() { + return kStopByte; +} + +template <typename C> +void EncodeInt32Tmpl(int32_t value, C* out) { + if (value >= 0) { + internals::WriteTokenStart(MajorType::UNSIGNED, value, out); + } else { + uint64_t representation = static_cast<uint64_t>(-(value + 1)); + internals::WriteTokenStart(MajorType::NEGATIVE, representation, out); + } +} +void EncodeInt32(int32_t value, std::vector<uint8_t>* out) { + EncodeInt32Tmpl(value, out); +} +void EncodeInt32(int32_t value, std::string* out) { + EncodeInt32Tmpl(value, out); +} + +template <typename C> +void EncodeString16Tmpl(span<uint16_t> in, C* out) { + uint64_t byte_length = static_cast<uint64_t>(in.size_bytes()); + internals::WriteTokenStart(MajorType::BYTE_STRING, byte_length, out); + // When emitting UTF16 characters, we always write the least significant byte + // first; this is because it's the native representation for X86. + // TODO(johannes): Implement a more efficient thing here later, e.g. + // casting *iff* the machine has this byte order. + // The wire format for UTF16 chars will probably remain the same + // (least significant byte first) since this way we can have + // golden files, unittests, etc. that port easily and universally. + // See also: + // https://commandcenter.blogspot.com/2012/04/byte-order-fallacy.html + for (const uint16_t two_bytes : in) { + out->push_back(two_bytes); + out->push_back(two_bytes >> 8); + } +} +void EncodeString16(span<uint16_t> in, std::vector<uint8_t>* out) { + EncodeString16Tmpl(in, out); +} +void EncodeString16(span<uint16_t> in, std::string* out) { + EncodeString16Tmpl(in, out); +} + +template <typename C> +void EncodeString8Tmpl(span<uint8_t> in, C* out) { + internals::WriteTokenStart(MajorType::STRING, + static_cast<uint64_t>(in.size_bytes()), out); + out->insert(out->end(), in.begin(), in.end()); +} +void EncodeString8(span<uint8_t> in, std::vector<uint8_t>* out) { + EncodeString8Tmpl(in, out); +} +void EncodeString8(span<uint8_t> in, std::string* out) { + EncodeString8Tmpl(in, out); +} + +template <typename C> +void EncodeFromLatin1Tmpl(span<uint8_t> latin1, C* out) { + for (size_t ii = 0; ii < latin1.size(); ++ii) { + if (latin1[ii] <= 127) + continue; + // If there's at least one non-ASCII char, convert to UTF8. + std::vector<uint8_t> utf8(latin1.begin(), latin1.begin() + ii); + for (; ii < latin1.size(); ++ii) { + if (latin1[ii] <= 127) { + utf8.push_back(latin1[ii]); + } else { + // 0xC0 means it's a UTF8 sequence with 2 bytes. + utf8.push_back((latin1[ii] >> 6) | 0xc0); + utf8.push_back((latin1[ii] | 0x80) & 0xbf); + } + } + EncodeString8(SpanFrom(utf8), out); + return; + } + EncodeString8(latin1, out); +} +void EncodeFromLatin1(span<uint8_t> latin1, std::vector<uint8_t>* out) { + EncodeFromLatin1Tmpl(latin1, out); +} +void EncodeFromLatin1(span<uint8_t> latin1, std::string* out) { + EncodeFromLatin1Tmpl(latin1, out); +} + +template <typename C> +void EncodeFromUTF16Tmpl(span<uint16_t> utf16, C* out) { + // If there's at least one non-ASCII char, encode as STRING16 (UTF16). + for (uint16_t ch : utf16) { + if (ch <= 127) + continue; + EncodeString16(utf16, out); + return; + } + // It's all US-ASCII, strip out every second byte and encode as UTF8. + internals::WriteTokenStart(MajorType::STRING, + static_cast<uint64_t>(utf16.size()), out); + out->insert(out->end(), utf16.begin(), utf16.end()); +} +void EncodeFromUTF16(span<uint16_t> utf16, std::vector<uint8_t>* out) { + EncodeFromUTF16Tmpl(utf16, out); +} +void EncodeFromUTF16(span<uint16_t> utf16, std::string* out) { + EncodeFromUTF16Tmpl(utf16, out); +} + +template <typename C> +void EncodeBinaryTmpl(span<uint8_t> in, C* out) { + out->push_back(kExpectedConversionToBase64Tag); + uint64_t byte_length = static_cast<uint64_t>(in.size_bytes()); + internals::WriteTokenStart(MajorType::BYTE_STRING, byte_length, out); + out->insert(out->end(), in.begin(), in.end()); +} +void EncodeBinary(span<uint8_t> in, std::vector<uint8_t>* out) { + EncodeBinaryTmpl(in, out); +} +void EncodeBinary(span<uint8_t> in, std::string* out) { + EncodeBinaryTmpl(in, out); +} + +// A double is encoded with a specific initial byte +// (kInitialByteForDouble) plus the 64 bits of payload for its value. +constexpr size_t kEncodedDoubleSize = 1 + sizeof(uint64_t); + +// An envelope is encoded with a specific initial byte +// (kInitialByteForEnvelope), plus the start byte for a BYTE_STRING with a 32 +// bit wide length, plus a 32 bit length for that string. +constexpr size_t kEncodedEnvelopeHeaderSize = 1 + 1 + sizeof(uint32_t); + +template <typename C> +void EncodeDoubleTmpl(double value, C* out) { + // The additional_info=27 indicates 64 bits for the double follow. + // See RFC 7049 Section 2.3, Table 1. + out->push_back(kInitialByteForDouble); + union { + double from_double; + uint64_t to_uint64; + } reinterpret; + reinterpret.from_double = value; + WriteBytesMostSignificantByteFirst<uint64_t>(reinterpret.to_uint64, out); +} +void EncodeDouble(double value, std::vector<uint8_t>* out) { + EncodeDoubleTmpl(value, out); +} +void EncodeDouble(double value, std::string* out) { + EncodeDoubleTmpl(value, out); +} + +// ============================================================================= +// cbor::EnvelopeEncoder - for wrapping submessages +// ============================================================================= + +template <typename C> +void EncodeStartTmpl(C* out, size_t* byte_size_pos) { + assert(*byte_size_pos == 0); + out->push_back(kInitialByteForEnvelope); + out->push_back(kInitialByteFor32BitLengthByteString); + *byte_size_pos = out->size(); + out->resize(out->size() + sizeof(uint32_t)); +} + +void EnvelopeEncoder::EncodeStart(std::vector<uint8_t>* out) { + EncodeStartTmpl<std::vector<uint8_t>>(out, &byte_size_pos_); +} + +void EnvelopeEncoder::EncodeStart(std::string* out) { + EncodeStartTmpl<std::string>(out, &byte_size_pos_); +} + +template <typename C> +bool EncodeStopTmpl(C* out, size_t* byte_size_pos) { + assert(*byte_size_pos != 0); + // The byte size is the size of the payload, that is, all the + // bytes that were written past the byte size position itself. + uint64_t byte_size = out->size() - (*byte_size_pos + sizeof(uint32_t)); + // We store exactly 4 bytes, so at most INT32MAX, with most significant + // byte first. + if (byte_size > std::numeric_limits<uint32_t>::max()) + return false; + for (int shift_bytes = sizeof(uint32_t) - 1; shift_bytes >= 0; + --shift_bytes) { + (*out)[(*byte_size_pos)++] = 0xff & (byte_size >> (shift_bytes * 8)); + } + return true; +} + +bool EnvelopeEncoder::EncodeStop(std::vector<uint8_t>* out) { + return EncodeStopTmpl(out, &byte_size_pos_); +} + +bool EnvelopeEncoder::EncodeStop(std::string* out) { + return EncodeStopTmpl(out, &byte_size_pos_); +} + +// ============================================================================= +// cbor::NewCBOREncoder - for encoding from a streaming parser +// ============================================================================= + +namespace { +template <typename C> +class CBOREncoder : public StreamingParserHandler { + public: + CBOREncoder(C* out, Status* status) : out_(out), status_(status) { + *status_ = Status(); + } + + void HandleMapBegin() override { + if (!status_->ok()) + return; + envelopes_.emplace_back(); + envelopes_.back().EncodeStart(out_); + out_->push_back(kInitialByteIndefiniteLengthMap); + } + + void HandleMapEnd() override { + if (!status_->ok()) + return; + out_->push_back(kStopByte); + assert(!envelopes_.empty()); + if (!envelopes_.back().EncodeStop(out_)) { + HandleError( + Status(Error::CBOR_ENVELOPE_SIZE_LIMIT_EXCEEDED, out_->size())); + return; + } + envelopes_.pop_back(); + } + + void HandleArrayBegin() override { + if (!status_->ok()) + return; + envelopes_.emplace_back(); + envelopes_.back().EncodeStart(out_); + out_->push_back(kInitialByteIndefiniteLengthArray); + } + + void HandleArrayEnd() override { + if (!status_->ok()) + return; + out_->push_back(kStopByte); + assert(!envelopes_.empty()); + if (!envelopes_.back().EncodeStop(out_)) { + HandleError( + Status(Error::CBOR_ENVELOPE_SIZE_LIMIT_EXCEEDED, out_->size())); + return; + } + envelopes_.pop_back(); + } + + void HandleString8(span<uint8_t> chars) override { + if (!status_->ok()) + return; + EncodeString8(chars, out_); + } + + void HandleString16(span<uint16_t> chars) override { + if (!status_->ok()) + return; + EncodeFromUTF16(chars, out_); + } + + void HandleBinary(span<uint8_t> bytes) override { + if (!status_->ok()) + return; + EncodeBinary(bytes, out_); + } + + void HandleDouble(double value) override { + if (!status_->ok()) + return; + EncodeDouble(value, out_); + } + + void HandleInt32(int32_t value) override { + if (!status_->ok()) + return; + EncodeInt32(value, out_); + } + + void HandleBool(bool value) override { + if (!status_->ok()) + return; + // See RFC 7049 Section 2.3, Table 2. + out_->push_back(value ? kEncodedTrue : kEncodedFalse); + } + + void HandleNull() override { + if (!status_->ok()) + return; + // See RFC 7049 Section 2.3, Table 2. + out_->push_back(kEncodedNull); + } + + void HandleError(Status error) override { + if (!status_->ok()) + return; + *status_ = error; + out_->clear(); + } + + private: + C* out_; + std::vector<EnvelopeEncoder> envelopes_; + Status* status_; +}; +} // namespace + +std::unique_ptr<StreamingParserHandler> NewCBOREncoder( + std::vector<uint8_t>* out, + Status* status) { + return std::unique_ptr<StreamingParserHandler>( + new CBOREncoder<std::vector<uint8_t>>(out, status)); +} +std::unique_ptr<StreamingParserHandler> NewCBOREncoder(std::string* out, + Status* status) { + return std::unique_ptr<StreamingParserHandler>( + new CBOREncoder<std::string>(out, status)); +} + +// ============================================================================= +// cbor::CBORTokenizer - for parsing individual CBOR items +// ============================================================================= + +CBORTokenizer::CBORTokenizer(span<uint8_t> bytes) : bytes_(bytes) { + ReadNextToken(/*enter_envelope=*/false); +} +CBORTokenizer::~CBORTokenizer() {} + +CBORTokenTag CBORTokenizer::TokenTag() const { + return token_tag_; +} + +void CBORTokenizer::Next() { + if (token_tag_ == CBORTokenTag::ERROR_VALUE || + token_tag_ == CBORTokenTag::DONE) + return; + ReadNextToken(/*enter_envelope=*/false); +} + +void CBORTokenizer::EnterEnvelope() { + assert(token_tag_ == CBORTokenTag::ENVELOPE); + ReadNextToken(/*enter_envelope=*/true); +} + +Status CBORTokenizer::Status() const { + return status_; +} + +// The following accessor functions ::GetInt32, ::GetDouble, +// ::GetString8, ::GetString16WireRep, ::GetBinary, ::GetEnvelopeContents +// assume that a particular token was recognized in ::ReadNextToken. +// That's where all the error checking is done. By design, +// the accessors (assuming the token was recognized) never produce +// an error. + +int32_t CBORTokenizer::GetInt32() const { + assert(token_tag_ == CBORTokenTag::INT32); + // The range checks happen in ::ReadNextToken(). + return static_cast<int32_t>( + token_start_type_ == MajorType::UNSIGNED + ? token_start_internal_value_ + : -static_cast<int64_t>(token_start_internal_value_) - 1); +} + +double CBORTokenizer::GetDouble() const { + assert(token_tag_ == CBORTokenTag::DOUBLE); + union { + uint64_t from_uint64; + double to_double; + } reinterpret; + reinterpret.from_uint64 = ReadBytesMostSignificantByteFirst<uint64_t>( + bytes_.subspan(status_.pos + 1)); + return reinterpret.to_double; +} + +span<uint8_t> CBORTokenizer::GetString8() const { + assert(token_tag_ == CBORTokenTag::STRING8); + auto length = static_cast<size_t>(token_start_internal_value_); + return bytes_.subspan(status_.pos + (token_byte_length_ - length), length); +} + +span<uint8_t> CBORTokenizer::GetString16WireRep() const { + assert(token_tag_ == CBORTokenTag::STRING16); + auto length = static_cast<size_t>(token_start_internal_value_); + return bytes_.subspan(status_.pos + (token_byte_length_ - length), length); +} + +span<uint8_t> CBORTokenizer::GetBinary() const { + assert(token_tag_ == CBORTokenTag::BINARY); + auto length = static_cast<size_t>(token_start_internal_value_); + return bytes_.subspan(status_.pos + (token_byte_length_ - length), length); +} + +span<uint8_t> CBORTokenizer::GetEnvelopeContents() const { + assert(token_tag_ == CBORTokenTag::ENVELOPE); + auto length = static_cast<size_t>(token_start_internal_value_); + return bytes_.subspan(status_.pos + kEncodedEnvelopeHeaderSize, length); +} + +// All error checking happens in ::ReadNextToken, so that the accessors +// can avoid having to carry an error return value. +// +// With respect to checking the encoded lengths of strings, arrays, etc: +// On the wire, CBOR uses 1,2,4, and 8 byte unsigned integers, so +// we initially read them as uint64_t, usually into token_start_internal_value_. +// +// However, since these containers have a representation on the machine, +// we need to do corresponding size computations on the input byte array, +// output span (e.g. the payload for a string), etc., and size_t is +// machine specific (in practice either 32 bit or 64 bit). +// +// Further, we must avoid overflowing size_t. Therefore, we use this +// kMaxValidLength constant to: +// - Reject values that are larger than the architecture specific +// max size_t (differs between 32 bit and 64 bit arch). +// - Reserve at least one bit so that we can check against overflows +// when adding lengths (array / string length / etc.); we do this by +// ensuring that the inputs to an addition are <= kMaxValidLength, +// and then checking whether the sum went past it. +// +// See also +// https://chromium.googlesource.com/chromium/src/+/master/docs/security/integer-semantics.md +static const uint64_t kMaxValidLength = + std::min<uint64_t>(std::numeric_limits<uint64_t>::max() >> 2, + std::numeric_limits<size_t>::max()); + +void CBORTokenizer::ReadNextToken(bool enter_envelope) { + if (enter_envelope) { + status_.pos += kEncodedEnvelopeHeaderSize; + } else { + status_.pos = + status_.pos == Status::npos() ? 0 : status_.pos + token_byte_length_; + } + status_.error = Error::OK; + if (status_.pos >= bytes_.size()) { + token_tag_ = CBORTokenTag::DONE; + return; + } + const size_t remaining_bytes = bytes_.size() - status_.pos; + switch (bytes_[status_.pos]) { + case kStopByte: + SetToken(CBORTokenTag::STOP, 1); + return; + case kInitialByteIndefiniteLengthMap: + SetToken(CBORTokenTag::MAP_START, 1); + return; + case kInitialByteIndefiniteLengthArray: + SetToken(CBORTokenTag::ARRAY_START, 1); + return; + case kEncodedTrue: + SetToken(CBORTokenTag::TRUE_VALUE, 1); + return; + case kEncodedFalse: + SetToken(CBORTokenTag::FALSE_VALUE, 1); + return; + case kEncodedNull: + SetToken(CBORTokenTag::NULL_VALUE, 1); + return; + case kExpectedConversionToBase64Tag: { // BINARY + const int8_t bytes_read = internals::ReadTokenStart( + bytes_.subspan(status_.pos + 1), &token_start_type_, + &token_start_internal_value_); + if (bytes_read < 0 || token_start_type_ != MajorType::BYTE_STRING || + token_start_internal_value_ > kMaxValidLength) { + SetError(Error::CBOR_INVALID_BINARY); + return; + } + const uint64_t token_byte_length = token_start_internal_value_ + + /* tag before token start: */ 1 + + /* token start: */ bytes_read; + if (token_byte_length > remaining_bytes) { + SetError(Error::CBOR_INVALID_BINARY); + return; + } + SetToken(CBORTokenTag::BINARY, static_cast<size_t>(token_byte_length)); + return; + } + case kInitialByteForDouble: { // DOUBLE + if (kEncodedDoubleSize > remaining_bytes) { + SetError(Error::CBOR_INVALID_DOUBLE); + return; + } + SetToken(CBORTokenTag::DOUBLE, kEncodedDoubleSize); + return; + } + case kInitialByteForEnvelope: { // ENVELOPE + if (kEncodedEnvelopeHeaderSize > remaining_bytes) { + SetError(Error::CBOR_INVALID_ENVELOPE); + return; + } + // The envelope must be a byte string with 32 bit length. + if (bytes_[status_.pos + 1] != kInitialByteFor32BitLengthByteString) { + SetError(Error::CBOR_INVALID_ENVELOPE); + return; + } + // Read the length of the byte string. + token_start_internal_value_ = ReadBytesMostSignificantByteFirst<uint32_t>( + bytes_.subspan(status_.pos + 2)); + if (token_start_internal_value_ > kMaxValidLength) { + SetError(Error::CBOR_INVALID_ENVELOPE); + return; + } + uint64_t token_byte_length = + token_start_internal_value_ + kEncodedEnvelopeHeaderSize; + if (token_byte_length > remaining_bytes) { + SetError(Error::CBOR_INVALID_ENVELOPE); + return; + } + SetToken(CBORTokenTag::ENVELOPE, static_cast<size_t>(token_byte_length)); + return; + } + default: { + const int8_t token_start_length = internals::ReadTokenStart( + bytes_.subspan(status_.pos), &token_start_type_, + &token_start_internal_value_); + const bool success = token_start_length >= 0; + switch (token_start_type_) { + case MajorType::UNSIGNED: // INT32. + // INT32 is a signed int32 (int32 makes sense for the + // inspector_protocol, it's not a CBOR limitation), so we check + // against the signed max, so that the allowable values are + // 0, 1, 2, ... 2^31 - 1. + if (!success || std::numeric_limits<int32_t>::max() < + token_start_internal_value_) { + SetError(Error::CBOR_INVALID_INT32); + return; + } + SetToken(CBORTokenTag::INT32, token_start_length); + return; + case MajorType::NEGATIVE: { // INT32. + // INT32 is a signed int32 (int32 makes sense for the + // inspector_protocol, it's not a CBOR limitation); in CBOR, + // the negative values for INT32 are represented as NEGATIVE, + // that is, -1 INT32 is represented as 1 << 5 | 0 (major type 1, + // additional info value 0). So here, we compute the INT32 value + // and then check it against the INT32 min. + int64_t actual_value = + -static_cast<int64_t>(token_start_internal_value_) - 1; + if (!success || actual_value < std::numeric_limits<int32_t>::min()) { + SetError(Error::CBOR_INVALID_INT32); + return; + } + SetToken(CBORTokenTag::INT32, token_start_length); + return; + } + case MajorType::STRING: { // STRING8. + if (!success || token_start_internal_value_ > kMaxValidLength) { + SetError(Error::CBOR_INVALID_STRING8); + return; + } + uint64_t token_byte_length = + token_start_internal_value_ + token_start_length; + if (token_byte_length > remaining_bytes) { + SetError(Error::CBOR_INVALID_STRING8); + return; + } + SetToken(CBORTokenTag::STRING8, + static_cast<size_t>(token_byte_length)); + return; + } + case MajorType::BYTE_STRING: { // STRING16. + // Length must be divisible by 2 since UTF16 is 2 bytes per + // character, hence the &1 check. + if (!success || token_start_internal_value_ > kMaxValidLength || + token_start_internal_value_ & 1) { + SetError(Error::CBOR_INVALID_STRING16); + return; + } + uint64_t token_byte_length = + token_start_internal_value_ + token_start_length; + if (token_byte_length > remaining_bytes) { + SetError(Error::CBOR_INVALID_STRING16); + return; + } + SetToken(CBORTokenTag::STRING16, + static_cast<size_t>(token_byte_length)); + return; + } + case MajorType::ARRAY: + case MajorType::MAP: + case MajorType::TAG: + case MajorType::SIMPLE_VALUE: + SetError(Error::CBOR_UNSUPPORTED_VALUE); + return; + } + } + } +} + +void CBORTokenizer::SetToken(CBORTokenTag token_tag, size_t token_byte_length) { + token_tag_ = token_tag; + token_byte_length_ = token_byte_length; +} + +void CBORTokenizer::SetError(Error error) { + token_tag_ = CBORTokenTag::ERROR_VALUE; + status_.error = error; +} + +// ============================================================================= +// cbor::ParseCBOR - for receiving streaming parser events for CBOR messages +// ============================================================================= + +namespace { +// When parsing CBOR, we limit recursion depth for objects and arrays +// to this constant. +static constexpr int kStackLimit = 300; + +// Below are three parsing routines for CBOR, which cover enough +// to roundtrip JSON messages. +bool ParseMap(int32_t stack_depth, + CBORTokenizer* tokenizer, + StreamingParserHandler* out); +bool ParseArray(int32_t stack_depth, + CBORTokenizer* tokenizer, + StreamingParserHandler* out); +bool ParseValue(int32_t stack_depth, + CBORTokenizer* tokenizer, + StreamingParserHandler* out); + +void ParseUTF16String(CBORTokenizer* tokenizer, StreamingParserHandler* out) { + std::vector<uint16_t> value; + span<uint8_t> rep = tokenizer->GetString16WireRep(); + for (size_t ii = 0; ii < rep.size(); ii += 2) + value.push_back((rep[ii + 1] << 8) | rep[ii]); + out->HandleString16(span<uint16_t>(value.data(), value.size())); + tokenizer->Next(); +} + +bool ParseUTF8String(CBORTokenizer* tokenizer, StreamingParserHandler* out) { + assert(tokenizer->TokenTag() == CBORTokenTag::STRING8); + out->HandleString8(tokenizer->GetString8()); + tokenizer->Next(); + return true; +} + +bool ParseValue(int32_t stack_depth, + CBORTokenizer* tokenizer, + StreamingParserHandler* out) { + if (stack_depth > kStackLimit) { + out->HandleError( + Status{Error::CBOR_STACK_LIMIT_EXCEEDED, tokenizer->Status().pos}); + return false; + } + // Skip past the envelope to get to what's inside. + if (tokenizer->TokenTag() == CBORTokenTag::ENVELOPE) + tokenizer->EnterEnvelope(); + switch (tokenizer->TokenTag()) { + case CBORTokenTag::ERROR_VALUE: + out->HandleError(tokenizer->Status()); + return false; + case CBORTokenTag::DONE: + out->HandleError(Status{Error::CBOR_UNEXPECTED_EOF_EXPECTED_VALUE, + tokenizer->Status().pos}); + return false; + case CBORTokenTag::TRUE_VALUE: + out->HandleBool(true); + tokenizer->Next(); + return true; + case CBORTokenTag::FALSE_VALUE: + out->HandleBool(false); + tokenizer->Next(); + return true; + case CBORTokenTag::NULL_VALUE: + out->HandleNull(); + tokenizer->Next(); + return true; + case CBORTokenTag::INT32: + out->HandleInt32(tokenizer->GetInt32()); + tokenizer->Next(); + return true; + case CBORTokenTag::DOUBLE: + out->HandleDouble(tokenizer->GetDouble()); + tokenizer->Next(); + return true; + case CBORTokenTag::STRING8: + return ParseUTF8String(tokenizer, out); + case CBORTokenTag::STRING16: + ParseUTF16String(tokenizer, out); + return true; + case CBORTokenTag::BINARY: { + out->HandleBinary(tokenizer->GetBinary()); + tokenizer->Next(); + return true; + } + case CBORTokenTag::MAP_START: + return ParseMap(stack_depth + 1, tokenizer, out); + case CBORTokenTag::ARRAY_START: + return ParseArray(stack_depth + 1, tokenizer, out); + default: + out->HandleError( + Status{Error::CBOR_UNSUPPORTED_VALUE, tokenizer->Status().pos}); + return false; + } +} + +// |bytes| must start with the indefinite length array byte, so basically, +// ParseArray may only be called after an indefinite length array has been +// detected. +bool ParseArray(int32_t stack_depth, + CBORTokenizer* tokenizer, + StreamingParserHandler* out) { + assert(tokenizer->TokenTag() == CBORTokenTag::ARRAY_START); + tokenizer->Next(); + out->HandleArrayBegin(); + while (tokenizer->TokenTag() != CBORTokenTag::STOP) { + if (tokenizer->TokenTag() == CBORTokenTag::DONE) { + out->HandleError( + Status{Error::CBOR_UNEXPECTED_EOF_IN_ARRAY, tokenizer->Status().pos}); + return false; + } + if (tokenizer->TokenTag() == CBORTokenTag::ERROR_VALUE) { + out->HandleError(tokenizer->Status()); + return false; + } + // Parse value. + if (!ParseValue(stack_depth, tokenizer, out)) + return false; + } + out->HandleArrayEnd(); + tokenizer->Next(); + return true; +} + +// |bytes| must start with the indefinite length array byte, so basically, +// ParseArray may only be called after an indefinite length array has been +// detected. +bool ParseMap(int32_t stack_depth, + CBORTokenizer* tokenizer, + StreamingParserHandler* out) { + assert(tokenizer->TokenTag() == CBORTokenTag::MAP_START); + out->HandleMapBegin(); + tokenizer->Next(); + while (tokenizer->TokenTag() != CBORTokenTag::STOP) { + if (tokenizer->TokenTag() == CBORTokenTag::DONE) { + out->HandleError( + Status{Error::CBOR_UNEXPECTED_EOF_IN_MAP, tokenizer->Status().pos}); + return false; + } + if (tokenizer->TokenTag() == CBORTokenTag::ERROR_VALUE) { + out->HandleError(tokenizer->Status()); + return false; + } + // Parse key. + if (tokenizer->TokenTag() == CBORTokenTag::STRING8) { + if (!ParseUTF8String(tokenizer, out)) + return false; + } else if (tokenizer->TokenTag() == CBORTokenTag::STRING16) { + ParseUTF16String(tokenizer, out); + } else { + out->HandleError( + Status{Error::CBOR_INVALID_MAP_KEY, tokenizer->Status().pos}); + return false; + } + // Parse value. + if (!ParseValue(stack_depth, tokenizer, out)) + return false; + } + out->HandleMapEnd(); + tokenizer->Next(); + return true; +} +} // namespace + +void ParseCBOR(span<uint8_t> bytes, StreamingParserHandler* out) { + if (bytes.empty()) { + out->HandleError(Status{Error::CBOR_NO_INPUT, 0}); + return; + } + if (bytes[0] != kInitialByteForEnvelope) { + out->HandleError(Status{Error::CBOR_INVALID_START_BYTE, 0}); + return; + } + CBORTokenizer tokenizer(bytes); + if (tokenizer.TokenTag() == CBORTokenTag::ERROR_VALUE) { + out->HandleError(tokenizer.Status()); + return; + } + // We checked for the envelope start byte above, so the tokenizer + // must agree here, since it's not an error. + assert(tokenizer.TokenTag() == CBORTokenTag::ENVELOPE); + tokenizer.EnterEnvelope(); + if (tokenizer.TokenTag() != CBORTokenTag::MAP_START) { + out->HandleError( + Status{Error::CBOR_MAP_START_EXPECTED, tokenizer.Status().pos}); + return; + } + if (!ParseMap(/*stack_depth=*/1, &tokenizer, out)) + return; + if (tokenizer.TokenTag() == CBORTokenTag::DONE) + return; + if (tokenizer.TokenTag() == CBORTokenTag::ERROR_VALUE) { + out->HandleError(tokenizer.Status()); + return; + } + out->HandleError(Status{Error::CBOR_TRAILING_JUNK, tokenizer.Status().pos}); +} + +// ============================================================================= +// cbor::AppendString8EntryToMap - for limited in-place editing of messages +// ============================================================================= + +template <typename C> +Status AppendString8EntryToCBORMapTmpl(span<uint8_t> string8_key, + span<uint8_t> string8_value, + C* cbor) { + // Careful below: Don't compare (*cbor)[idx] with a uint8_t, since + // it could be a char (signed!). Instead, use bytes. + span<uint8_t> bytes(reinterpret_cast<const uint8_t*>(cbor->data()), + cbor->size()); + CBORTokenizer tokenizer(bytes); + if (tokenizer.TokenTag() == CBORTokenTag::ERROR_VALUE) + return tokenizer.Status(); + if (tokenizer.TokenTag() != CBORTokenTag::ENVELOPE) + return Status(Error::CBOR_INVALID_ENVELOPE, 0); + size_t envelope_size = tokenizer.GetEnvelopeContents().size(); + size_t old_size = cbor->size(); + if (old_size != envelope_size + kEncodedEnvelopeHeaderSize) + return Status(Error::CBOR_INVALID_ENVELOPE, 0); + if (envelope_size == 0 || + (tokenizer.GetEnvelopeContents()[0] != EncodeIndefiniteLengthMapStart())) + return Status(Error::CBOR_MAP_START_EXPECTED, kEncodedEnvelopeHeaderSize); + if (bytes[bytes.size() - 1] != EncodeStop()) + return Status(Error::CBOR_MAP_STOP_EXPECTED, cbor->size() - 1); + cbor->pop_back(); + EncodeString8(string8_key, cbor); + EncodeString8(string8_value, cbor); + cbor->push_back(EncodeStop()); + size_t new_envelope_size = envelope_size + (cbor->size() - old_size); + if (new_envelope_size > std::numeric_limits<uint32_t>::max()) + return Status(Error::CBOR_ENVELOPE_SIZE_LIMIT_EXCEEDED, 0); + size_t size_pos = cbor->size() - new_envelope_size - sizeof(uint32_t); + uint8_t* out = reinterpret_cast<uint8_t*>(&cbor->at(size_pos)); + *(out++) = (new_envelope_size >> 24) & 0xff; + *(out++) = (new_envelope_size >> 16) & 0xff; + *(out++) = (new_envelope_size >> 8) & 0xff; + *(out) = new_envelope_size & 0xff; + return Status(); +} +Status AppendString8EntryToCBORMap(span<uint8_t> string8_key, + span<uint8_t> string8_value, + std::vector<uint8_t>* cbor) { + return AppendString8EntryToCBORMapTmpl(string8_key, string8_value, cbor); +} +Status AppendString8EntryToCBORMap(span<uint8_t> string8_key, + span<uint8_t> string8_value, + std::string* cbor) { + return AppendString8EntryToCBORMapTmpl(string8_key, string8_value, cbor); +} +} // namespace cbor + +namespace json { + +// ============================================================================= +// json::NewJSONEncoder - for encoding streaming parser events as JSON +// ============================================================================= + +namespace { +// Prints |value| to |out| with 4 hex digits, most significant chunk first. +template <typename C> +void PrintHex(uint16_t value, C* out) { + for (int ii = 3; ii >= 0; --ii) { + int four_bits = 0xf & (value >> (4 * ii)); + out->push_back(four_bits + ((four_bits <= 9) ? '0' : ('a' - 10))); + } +} + +// In the writer below, we maintain a stack of State instances. +// It is just enough to emit the appropriate delimiters and brackets +// in JSON. +enum class Container { + // Used for the top-level, initial state. + NONE, + // Inside a JSON object. + MAP, + // Inside a JSON array. + ARRAY +}; +class State { + public: + explicit State(Container container) : container_(container) {} + void StartElement(std::vector<uint8_t>* out) { StartElementTmpl(out); } + void StartElement(std::string* out) { StartElementTmpl(out); } + Container container() const { return container_; } + + private: + template <typename C> + void StartElementTmpl(C* out) { + assert(container_ != Container::NONE || size_ == 0); + if (size_ != 0) { + char delim = (!(size_ & 1) || container_ == Container::ARRAY) ? ',' : ':'; + out->push_back(delim); + } + ++size_; + } + + Container container_ = Container::NONE; + int size_ = 0; +}; + +constexpr char kBase64Table[] = + "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "abcdefghijklmnopqrstuvwxyz0123456789+/"; + +template <typename C> +void Base64Encode(const span<uint8_t>& in, C* out) { + // The following three cases are based on the tables in the example + // section in https://en.wikipedia.org/wiki/Base64. We process three + // input bytes at a time, emitting 4 output bytes at a time. + size_t ii = 0; + + // While possible, process three input bytes. + for (; ii + 3 <= in.size(); ii += 3) { + uint32_t twentyfour_bits = (in[ii] << 16) | (in[ii + 1] << 8) | in[ii + 2]; + out->push_back(kBase64Table[(twentyfour_bits >> 18)]); + out->push_back(kBase64Table[(twentyfour_bits >> 12) & 0x3f]); + out->push_back(kBase64Table[(twentyfour_bits >> 6) & 0x3f]); + out->push_back(kBase64Table[twentyfour_bits & 0x3f]); + } + if (ii + 2 <= in.size()) { // Process two input bytes. + uint32_t twentyfour_bits = (in[ii] << 16) | (in[ii + 1] << 8); + out->push_back(kBase64Table[(twentyfour_bits >> 18)]); + out->push_back(kBase64Table[(twentyfour_bits >> 12) & 0x3f]); + out->push_back(kBase64Table[(twentyfour_bits >> 6) & 0x3f]); + out->push_back('='); // Emit padding. + return; + } + if (ii + 1 <= in.size()) { // Process a single input byte. + uint32_t twentyfour_bits = (in[ii] << 16); + out->push_back(kBase64Table[(twentyfour_bits >> 18)]); + out->push_back(kBase64Table[(twentyfour_bits >> 12) & 0x3f]); + out->push_back('='); // Emit padding. + out->push_back('='); // Emit padding. + } +} + +// Implements a handler for JSON parser events to emit a JSON string. +template <typename C> +class JSONEncoder : public StreamingParserHandler { + public: + JSONEncoder(const Platform* platform, C* out, Status* status) + : platform_(platform), out_(out), status_(status) { + *status_ = Status(); + state_.emplace(Container::NONE); + } + + void HandleMapBegin() override { + if (!status_->ok()) + return; + assert(!state_.empty()); + state_.top().StartElement(out_); + state_.emplace(Container::MAP); + Emit('{'); + } + + void HandleMapEnd() override { + if (!status_->ok()) + return; + assert(state_.size() >= 2 && state_.top().container() == Container::MAP); + state_.pop(); + Emit('}'); + } + + void HandleArrayBegin() override { + if (!status_->ok()) + return; + state_.top().StartElement(out_); + state_.emplace(Container::ARRAY); + Emit('['); + } + + void HandleArrayEnd() override { + if (!status_->ok()) + return; + assert(state_.size() >= 2 && state_.top().container() == Container::ARRAY); + state_.pop(); + Emit(']'); + } + + void HandleString16(span<uint16_t> chars) override { + if (!status_->ok()) + return; + state_.top().StartElement(out_); + Emit('"'); + for (const uint16_t ch : chars) { + if (ch == '"') { + Emit("\\\""); + } else if (ch == '\\') { + Emit("\\\\"); + } else if (ch == '\b') { + Emit("\\b"); + } else if (ch == '\f') { + Emit("\\f"); + } else if (ch == '\n') { + Emit("\\n"); + } else if (ch == '\r') { + Emit("\\r"); + } else if (ch == '\t') { + Emit("\\t"); + } else if (ch >= 32 && ch <= 126) { + Emit(ch); + } else { + Emit("\\u"); + PrintHex(ch, out_); + } + } + Emit('"'); + } + + void HandleString8(span<uint8_t> chars) override { + if (!status_->ok()) + return; + state_.top().StartElement(out_); + Emit('"'); + for (size_t ii = 0; ii < chars.size(); ++ii) { + uint8_t c = chars[ii]; + if (c == '"') { + Emit("\\\""); + } else if (c == '\\') { + Emit("\\\\"); + } else if (c == '\b') { + Emit("\\b"); + } else if (c == '\f') { + Emit("\\f"); + } else if (c == '\n') { + Emit("\\n"); + } else if (c == '\r') { + Emit("\\r"); + } else if (c == '\t') { + Emit("\\t"); + } else if (c >= 32 && c <= 126) { + Emit(c); + } else if (c < 32) { + Emit("\\u"); + PrintHex(static_cast<uint16_t>(c), out_); + } else { + // Inspect the leading byte to figure out how long the utf8 + // byte sequence is; while doing this initialize |codepoint| + // with the first few bits. + // See table in: https://en.wikipedia.org/wiki/UTF-8 + // byte one is 110x xxxx -> 2 byte utf8 sequence + // byte one is 1110 xxxx -> 3 byte utf8 sequence + // byte one is 1111 0xxx -> 4 byte utf8 sequence + uint32_t codepoint; + int num_bytes_left; + if ((c & 0xe0) == 0xc0) { // 2 byte utf8 sequence + num_bytes_left = 1; + codepoint = c & 0x1f; + } else if ((c & 0xf0) == 0xe0) { // 3 byte utf8 sequence + num_bytes_left = 2; + codepoint = c & 0x0f; + } else if ((c & 0xf8) == 0xf0) { // 4 byte utf8 sequence + codepoint = c & 0x07; + num_bytes_left = 3; + } else { + continue; // invalid leading byte + } + + // If we have enough bytes in our input, decode the remaining ones + // belonging to this Unicode character into |codepoint|. + if (ii + num_bytes_left > chars.size()) + continue; + while (num_bytes_left > 0) { + c = chars[++ii]; + --num_bytes_left; + // Check the next byte is a continuation byte, that is 10xx xxxx. + if ((c & 0xc0) != 0x80) + continue; + codepoint = (codepoint << 6) | (c & 0x3f); + } + + // Disallow overlong encodings for ascii characters, as these + // would include " and other characters significant to JSON + // string termination / control. + if (codepoint < 0x7f) + continue; + // Invalid in UTF8, and can't be represented in UTF16 anyway. + if (codepoint > 0x10ffff) + continue; + + // So, now we transcode to UTF16, + // using the math described at https://en.wikipedia.org/wiki/UTF-16, + // for either one or two 16 bit characters. + if (codepoint < 0xffff) { + Emit("\\u"); + PrintHex(static_cast<uint16_t>(codepoint), out_); + continue; + } + codepoint -= 0x10000; + // high surrogate + Emit("\\u"); + PrintHex(static_cast<uint16_t>((codepoint >> 10) + 0xd800), out_); + // low surrogate + Emit("\\u"); + PrintHex(static_cast<uint16_t>((codepoint & 0x3ff) + 0xdc00), out_); + } + } + Emit('"'); + } + + void HandleBinary(span<uint8_t> bytes) override { + if (!status_->ok()) + return; + state_.top().StartElement(out_); + Emit('"'); + Base64Encode(bytes, out_); + Emit('"'); + } + + void HandleDouble(double value) override { + if (!status_->ok()) + return; + state_.top().StartElement(out_); + // JSON cannot represent NaN or Infinity. So, for compatibility, + // we behave like the JSON object in web browsers: emit 'null'. + if (!std::isfinite(value)) { + Emit("null"); + return; + } + std::unique_ptr<char[]> str_value = platform_->DToStr(value); + + // DToStr may fail to emit a 0 before the decimal dot. E.g. this is + // the case in base::NumberToString in Chromium (which is based on + // dmg_fp). So, much like + // https://cs.chromium.org/chromium/src/base/json/json_writer.cc + // we probe for this and emit the leading 0 anyway if necessary. + const char* chars = str_value.get(); + if (chars[0] == '.') { + Emit('0'); + } else if (chars[0] == '-' && chars[1] == '.') { + Emit("-0"); + ++chars; + } + Emit(chars); + } + + void HandleInt32(int32_t value) override { + if (!status_->ok()) + return; + state_.top().StartElement(out_); + Emit(std::to_string(value)); + } + + void HandleBool(bool value) override { + if (!status_->ok()) + return; + state_.top().StartElement(out_); + Emit(value ? "true" : "false"); + } + + void HandleNull() override { + if (!status_->ok()) + return; + state_.top().StartElement(out_); + Emit("null"); + } + + void HandleError(Status error) override { + assert(!error.ok()); + *status_ = error; + out_->clear(); + } + + private: + void Emit(char c) { out_->push_back(c); } + void Emit(const char* str) { + out_->insert(out_->end(), str, str + strlen(str)); + } + void Emit(const std::string& str) { + out_->insert(out_->end(), str.begin(), str.end()); + } + + const Platform* platform_; + C* out_; + Status* status_; + std::stack<State> state_; +}; +} // namespace + +std::unique_ptr<StreamingParserHandler> NewJSONEncoder( + const Platform* platform, + std::vector<uint8_t>* out, + Status* status) { + return std::unique_ptr<StreamingParserHandler>( + new JSONEncoder<std::vector<uint8_t>>(platform, out, status)); +} +std::unique_ptr<StreamingParserHandler> NewJSONEncoder(const Platform* platform, + std::string* out, + Status* status) { + return std::unique_ptr<StreamingParserHandler>( + new JSONEncoder<std::string>(platform, out, status)); +} + +// ============================================================================= +// json::ParseJSON - for receiving streaming parser events for JSON. +// ============================================================================= + +namespace { +const int kStackLimit = 300; + +enum Token { + ObjectBegin, + ObjectEnd, + ArrayBegin, + ArrayEnd, + StringLiteral, + Number, + BoolTrue, + BoolFalse, + NullToken, + ListSeparator, + ObjectPairSeparator, + InvalidToken, + NoInput +}; + +const char* const kNullString = "null"; +const char* const kTrueString = "true"; +const char* const kFalseString = "false"; + +template <typename Char> +class JsonParser { + public: + JsonParser(const Platform* platform, StreamingParserHandler* handler) + : platform_(platform), handler_(handler) {} + + void Parse(const Char* start, size_t length) { + start_pos_ = start; + const Char* end = start + length; + const Char* tokenEnd = nullptr; + ParseValue(start, end, &tokenEnd, 0); + if (error_) + return; + if (tokenEnd != end) { + HandleError(Error::JSON_PARSER_UNPROCESSED_INPUT_REMAINS, tokenEnd); + } + } + + private: + bool CharsToDouble(const uint16_t* chars, size_t length, double* result) { + std::string buffer; + buffer.reserve(length + 1); + for (size_t ii = 0; ii < length; ++ii) { + bool is_ascii = !(chars[ii] & ~0x7F); + if (!is_ascii) + return false; + buffer.push_back(static_cast<char>(chars[ii])); + } + return platform_->StrToD(buffer.c_str(), result); + } + + bool CharsToDouble(const uint8_t* chars, size_t length, double* result) { + std::string buffer(reinterpret_cast<const char*>(chars), length); + return platform_->StrToD(buffer.c_str(), result); + } + + static bool ParseConstToken(const Char* start, + const Char* end, + const Char** token_end, + const char* token) { + // |token| is \0 terminated, it's one of the constants at top of the file. + while (start < end && *token != '\0' && *start++ == *token++) { + } + if (*token != '\0') + return false; + *token_end = start; + return true; + } + + static bool ReadInt(const Char* start, + const Char* end, + const Char** token_end, + bool allow_leading_zeros) { + if (start == end) + return false; + bool has_leading_zero = '0' == *start; + int length = 0; + while (start < end && '0' <= *start && *start <= '9') { + ++start; + ++length; + } + if (!length) + return false; + if (!allow_leading_zeros && length > 1 && has_leading_zero) + return false; + *token_end = start; + return true; + } + + static bool ParseNumberToken(const Char* start, + const Char* end, + const Char** token_end) { + // We just grab the number here. We validate the size in DecodeNumber. + // According to RFC4627, a valid number is: [minus] int [frac] [exp] + if (start == end) + return false; + Char c = *start; + if ('-' == c) + ++start; + + if (!ReadInt(start, end, &start, /*allow_leading_zeros=*/false)) + return false; + if (start == end) { + *token_end = start; + return true; + } + + // Optional fraction part + c = *start; + if ('.' == c) { + ++start; + if (!ReadInt(start, end, &start, /*allow_leading_zeros=*/true)) + return false; + if (start == end) { + *token_end = start; + return true; + } + c = *start; + } + + // Optional exponent part + if ('e' == c || 'E' == c) { + ++start; + if (start == end) + return false; + c = *start; + if ('-' == c || '+' == c) { + ++start; + if (start == end) + return false; + } + if (!ReadInt(start, end, &start, /*allow_leading_zeros=*/true)) + return false; + } + + *token_end = start; + return true; + } + + static bool ReadHexDigits(const Char* start, + const Char* end, + const Char** token_end, + int digits) { + if (end - start < digits) + return false; + for (int i = 0; i < digits; ++i) { + Char c = *start++; + if (!(('0' <= c && c <= '9') || ('a' <= c && c <= 'f') || + ('A' <= c && c <= 'F'))) + return false; + } + *token_end = start; + return true; + } + + static bool ParseStringToken(const Char* start, + const Char* end, + const Char** token_end) { + while (start < end) { + Char c = *start++; + if ('\\' == c) { + if (start == end) + return false; + c = *start++; + // Make sure the escaped char is valid. + switch (c) { + case 'x': + if (!ReadHexDigits(start, end, &start, 2)) + return false; + break; + case 'u': + if (!ReadHexDigits(start, end, &start, 4)) + return false; + break; + case '\\': + case '/': + case 'b': + case 'f': + case 'n': + case 'r': + case 't': + case 'v': + case '"': + break; + default: + return false; + } + } else if ('"' == c) { + *token_end = start; + return true; + } + } + return false; + } + + static bool SkipComment(const Char* start, + const Char* end, + const Char** comment_end) { + if (start == end) + return false; + + if (*start != '/' || start + 1 >= end) + return false; + ++start; + + if (*start == '/') { + // Single line comment, read to newline. + for (++start; start < end; ++start) { + if (*start == '\n' || *start == '\r') { + *comment_end = start + 1; + return true; + } + } + *comment_end = end; + // Comment reaches end-of-input, which is fine. + return true; + } + + if (*start == '*') { + Char previous = '\0'; + // Block comment, read until end marker. + for (++start; start < end; previous = *start++) { + if (previous == '*' && *start == '/') { + *comment_end = start + 1; + return true; + } + } + // Block comment must close before end-of-input. + return false; + } + + return false; + } + + static bool IsSpaceOrNewLine(Char c) { + // \v = vertial tab; \f = form feed page break. + return c == ' ' || c == '\n' || c == '\v' || c == '\f' || c == '\r' || + c == '\t'; + } + + static void SkipWhitespaceAndComments(const Char* start, + const Char* end, + const Char** whitespace_end) { + while (start < end) { + if (IsSpaceOrNewLine(*start)) { + ++start; + } else if (*start == '/') { + const Char* comment_end = nullptr; + if (!SkipComment(start, end, &comment_end)) + break; + start = comment_end; + } else { + break; + } + } + *whitespace_end = start; + } + + static Token ParseToken(const Char* start, + const Char* end, + const Char** tokenStart, + const Char** token_end) { + SkipWhitespaceAndComments(start, end, tokenStart); + start = *tokenStart; + + if (start == end) + return NoInput; + + switch (*start) { + case 'n': + if (ParseConstToken(start, end, token_end, kNullString)) + return NullToken; + break; + case 't': + if (ParseConstToken(start, end, token_end, kTrueString)) + return BoolTrue; + break; + case 'f': + if (ParseConstToken(start, end, token_end, kFalseString)) + return BoolFalse; + break; + case '[': + *token_end = start + 1; + return ArrayBegin; + case ']': + *token_end = start + 1; + return ArrayEnd; + case ',': + *token_end = start + 1; + return ListSeparator; + case '{': + *token_end = start + 1; + return ObjectBegin; + case '}': + *token_end = start + 1; + return ObjectEnd; + case ':': + *token_end = start + 1; + return ObjectPairSeparator; + case '0': + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + case '-': + if (ParseNumberToken(start, end, token_end)) + return Number; + break; + case '"': + if (ParseStringToken(start + 1, end, token_end)) + return StringLiteral; + break; + } + return InvalidToken; + } + + static int HexToInt(Char c) { + if ('0' <= c && c <= '9') + return c - '0'; + if ('A' <= c && c <= 'F') + return c - 'A' + 10; + if ('a' <= c && c <= 'f') + return c - 'a' + 10; + assert(false); // Unreachable. + return 0; + } + + static bool DecodeString(const Char* start, + const Char* end, + std::vector<uint16_t>* output) { + if (start == end) + return true; + if (start > end) + return false; + output->reserve(end - start); + while (start < end) { + uint16_t c = *start++; + // If the |Char| we're dealing with is really a byte, then + // we have utf8 here, and we need to check for multibyte characters + // and transcode them to utf16 (either one or two utf16 chars). + if (sizeof(Char) == sizeof(uint8_t) && c >= 0x7f) { + // Inspect the leading byte to figure out how long the utf8 + // byte sequence is; while doing this initialize |codepoint| + // with the first few bits. + // See table in: https://en.wikipedia.org/wiki/UTF-8 + // byte one is 110x xxxx -> 2 byte utf8 sequence + // byte one is 1110 xxxx -> 3 byte utf8 sequence + // byte one is 1111 0xxx -> 4 byte utf8 sequence + uint32_t codepoint; + int num_bytes_left; + if ((c & 0xe0) == 0xc0) { // 2 byte utf8 sequence + num_bytes_left = 1; + codepoint = c & 0x1f; + } else if ((c & 0xf0) == 0xe0) { // 3 byte utf8 sequence + num_bytes_left = 2; + codepoint = c & 0x0f; + } else if ((c & 0xf8) == 0xf0) { // 4 byte utf8 sequence + codepoint = c & 0x07; + num_bytes_left = 3; + } else { + return false; // invalid leading byte + } + + // If we have enough bytes in our inpput, decode the remaining ones + // belonging to this Unicode character into |codepoint|. + if (start + num_bytes_left > end) + return false; + while (num_bytes_left > 0) { + c = *start++; + --num_bytes_left; + // Check the next byte is a continuation byte, that is 10xx xxxx. + if ((c & 0xc0) != 0x80) + return false; + codepoint = (codepoint << 6) | (c & 0x3f); + } + + // Disallow overlong encodings for ascii characters, as these + // would include " and other characters significant to JSON + // string termination / control. + if (codepoint < 0x7f) + return false; + // Invalid in UTF8, and can't be represented in UTF16 anyway. + if (codepoint > 0x10ffff) + return false; + + // So, now we transcode to UTF16, + // using the math described at https://en.wikipedia.org/wiki/UTF-16, + // for either one or two 16 bit characters. + if (codepoint < 0xffff) { + output->push_back(codepoint); + continue; + } + codepoint -= 0x10000; + output->push_back((codepoint >> 10) + 0xd800); // high surrogate + output->push_back((codepoint & 0x3ff) + 0xdc00); // low surrogate + continue; + } + if ('\\' != c) { + output->push_back(c); + continue; + } + if (start == end) + return false; + c = *start++; + + if (c == 'x') { + // \x is not supported. + return false; + } + + switch (c) { + case '"': + case '/': + case '\\': + break; + case 'b': + c = '\b'; + break; + case 'f': + c = '\f'; + break; + case 'n': + c = '\n'; + break; + case 'r': + c = '\r'; + break; + case 't': + c = '\t'; + break; + case 'v': + c = '\v'; + break; + case 'u': + c = (HexToInt(*start) << 12) + (HexToInt(*(start + 1)) << 8) + + (HexToInt(*(start + 2)) << 4) + HexToInt(*(start + 3)); + start += 4; + break; + default: + return false; + } + output->push_back(c); + } + return true; + } + + void ParseValue(const Char* start, + const Char* end, + const Char** value_token_end, + int depth) { + if (depth > kStackLimit) { + HandleError(Error::JSON_PARSER_STACK_LIMIT_EXCEEDED, start); + return; + } + const Char* token_start = nullptr; + const Char* token_end = nullptr; + Token token = ParseToken(start, end, &token_start, &token_end); + switch (token) { + case NoInput: + HandleError(Error::JSON_PARSER_NO_INPUT, token_start); + return; + case InvalidToken: + HandleError(Error::JSON_PARSER_INVALID_TOKEN, token_start); + return; + case NullToken: + handler_->HandleNull(); + break; + case BoolTrue: + handler_->HandleBool(true); + break; + case BoolFalse: + handler_->HandleBool(false); + break; + case Number: { + double value; + if (!CharsToDouble(token_start, token_end - token_start, &value)) { + HandleError(Error::JSON_PARSER_INVALID_NUMBER, token_start); + return; + } + if (value >= std::numeric_limits<int32_t>::min() && + value <= std::numeric_limits<int32_t>::max() && + static_cast<int32_t>(value) == value) + handler_->HandleInt32(static_cast<int32_t>(value)); + else + handler_->HandleDouble(value); + break; + } + case StringLiteral: { + std::vector<uint16_t> value; + bool ok = DecodeString(token_start + 1, token_end - 1, &value); + if (!ok) { + HandleError(Error::JSON_PARSER_INVALID_STRING, token_start); + return; + } + handler_->HandleString16(span<uint16_t>(value.data(), value.size())); + break; + } + case ArrayBegin: { + handler_->HandleArrayBegin(); + start = token_end; + token = ParseToken(start, end, &token_start, &token_end); + while (token != ArrayEnd) { + ParseValue(start, end, &token_end, depth + 1); + if (error_) + return; + + // After a list value, we expect a comma or the end of the list. + start = token_end; + token = ParseToken(start, end, &token_start, &token_end); + if (token == ListSeparator) { + start = token_end; + token = ParseToken(start, end, &token_start, &token_end); + if (token == ArrayEnd) { + HandleError(Error::JSON_PARSER_UNEXPECTED_ARRAY_END, token_start); + return; + } + } else if (token != ArrayEnd) { + // Unexpected value after list value. Bail out. + HandleError(Error::JSON_PARSER_COMMA_OR_ARRAY_END_EXPECTED, + token_start); + return; + } + } + handler_->HandleArrayEnd(); + break; + } + case ObjectBegin: { + handler_->HandleMapBegin(); + start = token_end; + token = ParseToken(start, end, &token_start, &token_end); + while (token != ObjectEnd) { + if (token != StringLiteral) { + HandleError(Error::JSON_PARSER_STRING_LITERAL_EXPECTED, + token_start); + return; + } + std::vector<uint16_t> key; + if (!DecodeString(token_start + 1, token_end - 1, &key)) { + HandleError(Error::JSON_PARSER_INVALID_STRING, token_start); + return; + } + handler_->HandleString16(span<uint16_t>(key.data(), key.size())); + start = token_end; + + token = ParseToken(start, end, &token_start, &token_end); + if (token != ObjectPairSeparator) { + HandleError(Error::JSON_PARSER_COLON_EXPECTED, token_start); + return; + } + start = token_end; + + ParseValue(start, end, &token_end, depth + 1); + if (error_) + return; + start = token_end; + + // After a key/value pair, we expect a comma or the end of the + // object. + token = ParseToken(start, end, &token_start, &token_end); + if (token == ListSeparator) { + start = token_end; + token = ParseToken(start, end, &token_start, &token_end); + if (token == ObjectEnd) { + HandleError(Error::JSON_PARSER_UNEXPECTED_MAP_END, token_start); + return; + } + } else if (token != ObjectEnd) { + // Unexpected value after last object value. Bail out. + HandleError(Error::JSON_PARSER_COMMA_OR_MAP_END_EXPECTED, + token_start); + return; + } + } + handler_->HandleMapEnd(); + break; + } + + default: + // We got a token that's not a value. + HandleError(Error::JSON_PARSER_VALUE_EXPECTED, token_start); + return; + } + + SkipWhitespaceAndComments(token_end, end, value_token_end); + } + + void HandleError(Error error, const Char* pos) { + assert(error != Error::OK); + if (!error_) { + handler_->HandleError( + Status{error, static_cast<size_t>(pos - start_pos_)}); + error_ = true; + } + } + + const Char* start_pos_ = nullptr; + bool error_ = false; + const Platform* platform_; + StreamingParserHandler* handler_; +}; +} // namespace + +void ParseJSON(const Platform& platform, + span<uint8_t> chars, + StreamingParserHandler* handler) { + JsonParser<uint8_t> parser(&platform, handler); + parser.Parse(chars.data(), chars.size()); +} + +void ParseJSON(const Platform& platform, + span<uint16_t> chars, + StreamingParserHandler* handler) { + JsonParser<uint16_t> parser(&platform, handler); + parser.Parse(chars.data(), chars.size()); +} + +// ============================================================================= +// json::ConvertCBORToJSON, json::ConvertJSONToCBOR - for transcoding +// ============================================================================= +template <typename C> +Status ConvertCBORToJSONTmpl(const Platform& platform, + span<uint8_t> cbor, + C* json) { + Status status; + std::unique_ptr<StreamingParserHandler> json_writer = + NewJSONEncoder(&platform, json, &status); + cbor::ParseCBOR(cbor, json_writer.get()); + return status; +} + +Status ConvertCBORToJSON(const Platform& platform, + span<uint8_t> cbor, + std::vector<uint8_t>* json) { + return ConvertCBORToJSONTmpl(platform, cbor, json); +} +Status ConvertCBORToJSON(const Platform& platform, + span<uint8_t> cbor, + std::string* json) { + return ConvertCBORToJSONTmpl(platform, cbor, json); +} + +template <typename T, typename C> +Status ConvertJSONToCBORTmpl(const Platform& platform, span<T> json, C* cbor) { + Status status; + std::unique_ptr<StreamingParserHandler> encoder = + cbor::NewCBOREncoder(cbor, &status); + ParseJSON(platform, json, encoder.get()); + return status; +} +Status ConvertJSONToCBOR(const Platform& platform, + span<uint8_t> json, + std::string* cbor) { + return ConvertJSONToCBORTmpl(platform, json, cbor); +} +Status ConvertJSONToCBOR(const Platform& platform, + span<uint16_t> json, + std::string* cbor) { + return ConvertJSONToCBORTmpl(platform, json, cbor); +} +Status ConvertJSONToCBOR(const Platform& platform, + span<uint8_t> json, + std::vector<uint8_t>* cbor) { + return ConvertJSONToCBORTmpl(platform, json, cbor); +} +Status ConvertJSONToCBOR(const Platform& platform, + span<uint16_t> json, + std::vector<uint8_t>* cbor) { + return ConvertJSONToCBORTmpl(platform, json, cbor); +} +} // namespace json + +{% for namespace in config.protocol.namespace %} +} // namespace {{namespace}} +{% endfor %} |