diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/serialize.h | 100 | ||||
| -rw-r--r-- | src/undo.h | 69 |
2 files changed, 81 insertions, 88 deletions
diff --git a/src/serialize.h b/src/serialize.h index 7fa669ebdb..75d6b52154 100644 --- a/src/serialize.h +++ b/src/serialize.h @@ -25,6 +25,9 @@ static const unsigned int MAX_SIZE = 0x02000000; +/** Maximum amount of memory (in bytes) to allocate at once when deserializing vectors. */ +static const unsigned int MAX_VECTOR_ALLOCATE = 5000000; + /** * Dummy data type to identify deserializing constructors. * @@ -593,6 +596,53 @@ public: template<typename I> BigEndian<I> WrapBigEndian(I& n) { return BigEndian<I>(n); } +/** Formatter to serialize/deserialize vector elements using another formatter + * + * Example: + * struct X { + * std::vector<uint64_t> v; + * SERIALIZE_METHODS(X, obj) { READWRITE(Using<VectorFormatter<VarInt>>(obj.v)); } + * }; + * will define a struct that contains a vector of uint64_t, which is serialized + * as a vector of VarInt-encoded integers. + * + * V is not required to be an std::vector type. It works for any class that + * exposes a value_type, size, reserve, push_back, and const iterators. + */ +template<class Formatter> +struct VectorFormatter +{ + template<typename Stream, typename V> + void Ser(Stream& s, const V& v) + { + WriteCompactSize(s, v.size()); + for (const typename V::value_type& elem : v) { + s << Using<Formatter>(elem); + } + } + + template<typename Stream, typename V> + void Unser(Stream& s, V& v) + { + v.clear(); + size_t size = ReadCompactSize(s); + size_t allocated = 0; + while (allocated < size) { + // For DoS prevention, do not blindly allocate as much as the stream claims to contain. + // Instead, allocate in 5MiB batches, so that an attacker actually needs to provide + // X MiB of data to make us allocate X+5 Mib. + static_assert(sizeof(typename V::value_type) <= MAX_VECTOR_ALLOCATE, "Vector element size too large"); + allocated = std::min(size, allocated + MAX_VECTOR_ALLOCATE / sizeof(typename V::value_type)); + v.reserve(allocated); + while (v.size() < allocated) { + typename V::value_type val; + s >> Using<Formatter>(val); + v.push_back(std::move(val)); + } + } + }; +}; + /** * Forward declarations */ @@ -673,6 +723,20 @@ inline void Unserialize(Stream& is, T&& a) a.Unserialize(is); } +/** Default formatter. Serializes objects as themselves. + * + * The vector/prevector serialization code passes this to VectorFormatter + * to enable reusing that logic. It shouldn't be needed elsewhere. + */ +struct DefaultFormatter +{ + template<typename Stream, typename T> + static void Ser(Stream& s, const T& t) { Serialize(s, t); } + + template<typename Stream, typename T> + static void Unser(Stream& s, T& t) { Unserialize(s, t); } +}; + @@ -713,9 +777,7 @@ void Serialize_impl(Stream& os, const prevector<N, T>& v, const unsigned char&) template<typename Stream, unsigned int N, typename T, typename V> void Serialize_impl(Stream& os, const prevector<N, T>& v, const V&) { - WriteCompactSize(os, v.size()); - for (typename prevector<N, T>::const_iterator vi = v.begin(); vi != v.end(); ++vi) - ::Serialize(os, (*vi)); + Serialize(os, Using<VectorFormatter<DefaultFormatter>>(v)); } template<typename Stream, unsigned int N, typename T> @@ -744,19 +806,7 @@ void Unserialize_impl(Stream& is, prevector<N, T>& v, const unsigned char&) template<typename Stream, unsigned int N, typename T, typename V> void Unserialize_impl(Stream& is, prevector<N, T>& v, const V&) { - v.clear(); - unsigned int nSize = ReadCompactSize(is); - unsigned int i = 0; - unsigned int nMid = 0; - while (nMid < nSize) - { - nMid += 5000000 / sizeof(T); - if (nMid > nSize) - nMid = nSize; - v.resize_uninitialized(nMid); - for (; i < nMid; ++i) - Unserialize(is, v[i]); - } + Unserialize(is, Using<VectorFormatter<DefaultFormatter>>(v)); } template<typename Stream, unsigned int N, typename T> @@ -793,9 +843,7 @@ void Serialize_impl(Stream& os, const std::vector<T, A>& v, const bool&) template<typename Stream, typename T, typename A, typename V> void Serialize_impl(Stream& os, const std::vector<T, A>& v, const V&) { - WriteCompactSize(os, v.size()); - for (typename std::vector<T, A>::const_iterator vi = v.begin(); vi != v.end(); ++vi) - ::Serialize(os, (*vi)); + Serialize(os, Using<VectorFormatter<DefaultFormatter>>(v)); } template<typename Stream, typename T, typename A> @@ -824,19 +872,7 @@ void Unserialize_impl(Stream& is, std::vector<T, A>& v, const unsigned char&) template<typename Stream, typename T, typename A, typename V> void Unserialize_impl(Stream& is, std::vector<T, A>& v, const V&) { - v.clear(); - unsigned int nSize = ReadCompactSize(is); - unsigned int i = 0; - unsigned int nMid = 0; - while (nMid < nSize) - { - nMid += 5000000 / sizeof(T); - if (nMid > nSize) - nMid = nSize; - v.resize(nMid); - for (; i < nMid; i++) - Unserialize(is, v[i]); - } + Unserialize(is, Using<VectorFormatter<DefaultFormatter>>(v)); } template<typename Stream, typename T, typename A> diff --git a/src/undo.h b/src/undo.h index 2009c721ab..47f132c7d8 100644 --- a/src/undo.h +++ b/src/undo.h @@ -13,58 +13,42 @@ #include <serialize.h> #include <version.h> -/** Undo information for a CTxIn +/** Formatter for undo information for a CTxIn * * Contains the prevout's CTxOut being spent, and its metadata as well * (coinbase or not, height). The serialization contains a dummy value of * zero. This is compatible with older versions which expect to see * the transaction version there. */ -class TxInUndoSerializer +struct TxInUndoFormatter { - const Coin* txout; - -public: template<typename Stream> - void Serialize(Stream &s) const { - ::Serialize(s, VARINT(txout->nHeight * 2 + (txout->fCoinBase ? 1u : 0u))); - if (txout->nHeight > 0) { + void Ser(Stream &s, const Coin& txout) { + ::Serialize(s, VARINT(txout.nHeight * 2 + (txout.fCoinBase ? 1u : 0u))); + if (txout.nHeight > 0) { // Required to maintain compatibility with older undo format. ::Serialize(s, (unsigned char)0); } - ::Serialize(s, Using<TxOutCompression>(REF(txout->out))); + ::Serialize(s, Using<TxOutCompression>(txout.out)); } - explicit TxInUndoSerializer(const Coin* coin) : txout(coin) {} -}; - -class TxInUndoDeserializer -{ - Coin* txout; - -public: template<typename Stream> - void Unserialize(Stream &s) { + void Unser(Stream &s, Coin& txout) { unsigned int nCode = 0; ::Unserialize(s, VARINT(nCode)); - txout->nHeight = nCode / 2; - txout->fCoinBase = nCode & 1; - if (txout->nHeight > 0) { + txout.nHeight = nCode / 2; + txout.fCoinBase = nCode & 1; + if (txout.nHeight > 0) { // Old versions stored the version number for the last spend of // a transaction's outputs. Non-final spends were indicated with // height = 0. unsigned int nVersionDummy; ::Unserialize(s, VARINT(nVersionDummy)); } - ::Unserialize(s, Using<TxOutCompression>(REF(txout->out))); + ::Unserialize(s, Using<TxOutCompression>(txout.out)); } - - explicit TxInUndoDeserializer(Coin* coin) : txout(coin) {} }; -static const size_t MIN_TRANSACTION_INPUT_WEIGHT = WITNESS_SCALE_FACTOR * ::GetSerializeSize(CTxIn(), PROTOCOL_VERSION); -static const size_t MAX_INPUTS_PER_BLOCK = MAX_BLOCK_WEIGHT / MIN_TRANSACTION_INPUT_WEIGHT; - /** Undo information for a CTransaction */ class CTxUndo { @@ -72,29 +56,7 @@ public: // undo information for all txins std::vector<Coin> vprevout; - template <typename Stream> - void Serialize(Stream& s) const { - // TODO: avoid reimplementing vector serializer - uint64_t count = vprevout.size(); - ::Serialize(s, COMPACTSIZE(REF(count))); - for (const auto& prevout : vprevout) { - ::Serialize(s, TxInUndoSerializer(&prevout)); - } - } - - template <typename Stream> - void Unserialize(Stream& s) { - // TODO: avoid reimplementing vector deserializer - uint64_t count = 0; - ::Unserialize(s, COMPACTSIZE(count)); - if (count > MAX_INPUTS_PER_BLOCK) { - throw std::ios_base::failure("Too many input undo records"); - } - vprevout.resize(count); - for (auto& prevout : vprevout) { - ::Unserialize(s, TxInUndoDeserializer(&prevout)); - } - } + SERIALIZE_METHODS(CTxUndo, obj) { READWRITE(Using<VectorFormatter<TxInUndoFormatter>>(obj.vprevout)); } }; /** Undo information for a CBlock */ @@ -103,12 +65,7 @@ class CBlockUndo public: std::vector<CTxUndo> vtxundo; // for all but the coinbase - ADD_SERIALIZE_METHODS; - - template <typename Stream, typename Operation> - inline void SerializationOp(Stream& s, Operation ser_action) { - READWRITE(vtxundo); - } + SERIALIZE_METHODS(CBlockUndo, obj) { READWRITE(obj.vtxundo); } }; #endif // BITCOIN_UNDO_H |