quic: implement various utilities classes to be used by the quic impl

node.gyp

@@ -335,6 +335,14 @@
       'src/node_crypto.cc',
       'src/node_crypto.h',
     ],
+    'node_quic_sources': [
+      'src/quic/cid.cc',
+      'src/quic/data.cc',
+      'src/quic/preferredaddress.cc',
+      'src/quic/cid.h',
+      'src/quic/data.h',
+      'src/quic/preferredaddress.h',
+    ],
     'node_mksnapshot_exec': '<(PRODUCT_DIR)/<(EXECUTABLE_PREFIX)node_mksnapshot<(EXECUTABLE_SUFFIX)',
     'conditions': [
       ['GENERATOR == "ninja"', {
@@ -836,6 +844,7 @@
         [ 'node_use_openssl=="true"', {
           'sources': [
             '<@(node_crypto_sources)',
+            '<@(node_quic_sources)',
           ],
         }],
         [ 'OS in "linux freebsd mac solaris" and '
@@ -1023,6 +1032,7 @@
           'sources': [
             'test/cctest/test_crypto_clienthello.cc',
             'test/cctest/test_node_crypto.cc',
+            'test/cctest/test_quic_cid.cc',
           ]
         }],
         ['v8_enable_inspector==1', {

src/quic/cid.cc

@@ -0,0 +1,148 @@
+#if HAVE_OPENSSL && NODE_OPENSSL_HAS_QUIC
+#include "cid.h"
+#include <crypto/crypto_util.h>
+#include <memory_tracker-inl.h>
+#include <node_mutex.h>
+#include <string_bytes.h>
+
+namespace node {
+namespace quic {
+
+// ============================================================================
+// CID
+
+CID::CID() : ptr_(&cid_) {
+  cid_.datalen = 0;
+}
+
+CID::CID(const ngtcp2_cid& cid) : CID(cid.data, cid.datalen) {}
+
+CID::CID(const uint8_t* data, size_t len) : CID() {
+  DCHECK_GE(len, kMinLength);
+  DCHECK_LE(len, kMaxLength);
+  ngtcp2_cid_init(&cid_, data, len);
+}
+
+CID::CID(const ngtcp2_cid* cid) : ptr_(cid) {
+  CHECK_NOT_NULL(cid);
+  DCHECK_GE(cid->datalen, kMinLength);
+  DCHECK_LE(cid->datalen, kMaxLength);
+}
+
+CID::CID(const CID& other) : ptr_(&cid_) {
+  CHECK_NOT_NULL(other.ptr_);
+  ngtcp2_cid_init(&cid_, other.ptr_->data, other.ptr_->datalen);
+}
+
+bool CID::operator==(const CID& other) const noexcept {
+  if (this == &other || (length() == 0 && other.length() == 0)) return true;
+  if (length() != other.length()) return false;
+  return memcmp(ptr_->data, other.ptr_->data, ptr_->datalen) == 0;
+}
+
+bool CID::operator!=(const CID& other) const noexcept {
+  return !(*this == other);
+}
+
+CID::operator const uint8_t*() const {
+  return ptr_->data;
+}
+CID::operator const ngtcp2_cid&() const {
+  return *ptr_;
+}
+CID::operator const ngtcp2_cid*() const {
+  return ptr_;
+}
+CID::operator bool() const {
+  return ptr_->datalen >= kMinLength;
+}
+
+size_t CID::length() const {
+  return ptr_->datalen;
+}
+
+std::string CID::ToString() const {
+  char dest[kMaxLength * 2];
+  size_t written =
+      StringBytes::hex_encode(reinterpret_cast<const char*>(ptr_->data),
+                              ptr_->datalen,
+                              dest,
+                              arraysize(dest));
+  return std::string(dest, written);
+}
+
+CID CID::kInvalid{};
+
+// ============================================================================
+// CID::Hash
+
+size_t CID::Hash::operator()(const CID& cid) const {
+  size_t hash = 0;
+  for (size_t n = 0; n < cid.length(); n++) {
+    hash ^= std::hash<uint8_t>{}(cid.ptr_->data[n] + 0x9e3779b9 + (hash << 6) +
+                                 (hash >> 2));
+  }
+  return hash;
+}
+
+// ============================================================================
+// CID::Factory
+
+namespace {
+class RandomCIDFactory : public CID::Factory {
+ public:
+  RandomCIDFactory() = default;
+  RandomCIDFactory(const RandomCIDFactory&) = delete;
+  RandomCIDFactory(RandomCIDFactory&&) = delete;
+  RandomCIDFactory& operator=(const RandomCIDFactory&) = delete;
+  RandomCIDFactory& operator=(RandomCIDFactory&&) = delete;
+
+  CID Generate(size_t length_hint) const override {
+    DCHECK_GE(length_hint, CID::kMinLength);
+    DCHECK_LE(length_hint, CID::kMaxLength);
+    Mutex::ScopedLock lock(mutex_);
+    maybe_refresh_pool(length_hint);
+    auto start = pool_ + pos_;
+    pos_ += length_hint;
+    return CID(start, length_hint);
+  }
+
+  void GenerateInto(ngtcp2_cid* cid,
+                    size_t length_hint = CID::kMaxLength) const override {
+    DCHECK_GE(length_hint, CID::kMinLength);
+    DCHECK_LE(length_hint, CID::kMaxLength);
+    Mutex::ScopedLock lock(mutex_);
+    maybe_refresh_pool(length_hint);
+    auto start = pool_ + pos_;
+    pos_ += length_hint;
+    ngtcp2_cid_init(cid, start, length_hint);
+  }
+
+ private:
+  void maybe_refresh_pool(size_t length_hint) const {
+    // We generate a pool of random data kPoolSize in length
+    // and pull our random CID from that. If we don't have
+    // enough random random remaining in the pool to generate
+    // a CID of the requested size, we regenerate the pool
+    // and reset it to zero.
+    if (pos_ + length_hint > kPoolSize) {
+      CHECK(crypto::CSPRNG(pool_, kPoolSize).is_ok());
+      pos_ = 0;
+    }
+  }
+
+  static constexpr int kPoolSize = 4096;
+  mutable int pos_ = kPoolSize;
+  mutable uint8_t pool_[kPoolSize];
+  mutable Mutex mutex_;
+};
+}  // namespace
+
+const CID::Factory& CID::Factory::random() {
+  static RandomCIDFactory instance;
+  return instance;
+}
+
+}  // namespace quic
+}  // namespace node
+#endif  // HAVE_OPENSSL && NODE_OPENSSL_HAS_QUIC

src/quic/cid.h

@@ -0,0 +1,126 @@
+#pragma once
+
+#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
+#if HAVE_OPENSSL && NODE_OPENSSL_HAS_QUIC
+#include <memory_tracker.h>
+#include <ngtcp2/ngtcp2.h>
+#include <string>
+
+namespace node {
+namespace quic {
+
+// CIDS are used to identify endpoints participating in a QUIC session.
+// Once created, CID instances are immutable.
+//
+// CIDs contain between 1 to 20 bytes. Most typically they are selected
+// randomly but there is a spec for creating "routable" CIDs that encode
+// a specific structure that is meaningful only to the side that creates
+// the CID. For most purposes, CIDs should be treated as opaque tokens.
+//
+// Each peer in a QUIC session generates one or more CIDs that the *other*
+// peer will use to identify the session. When a QUIC client initiates a
+// brand new session, it will initially generates a CID of its own (its
+// source CID) and a random placeholder CID for the server (the original
+// destination CID). When the server receives the initial packet, it will
+// generate its own source CID and use the clients source CID as the
+// server's destination CID.
+//
+//       Client                 Server
+// -------------------------------------------
+//     Source CID   <====> Destination CID
+//  Destination CID <====>   Source CID
+//
+// While the connection is being established, it is possible for either
+// peer to generate additional CIDs that are also associated with the
+// connection.
+class CID final : public MemoryRetainer {
+ public:
+  static constexpr size_t kMinLength = NGTCP2_MIN_CIDLEN;
+  static constexpr size_t kMaxLength = NGTCP2_MAX_CIDLEN;
+
+  // Copy the given ngtcp2_cid.
+  explicit CID(const ngtcp2_cid& cid);
+
+  // Copy the given buffer as a CID. The len must be within
+  // kMinLength and kMaxLength.
+  explicit CID(const uint8_t* data, size_t len);
+
+  // Wrap the given ngtcp2_cid. The CID does not take ownership
+  // of the underlying ngtcp2_cid.
+  explicit CID(const ngtcp2_cid* cid);
+
+  CID(const CID& other);
+  CID(CID&& other) = delete;
+
+  struct Hash final {
+    size_t operator()(const CID& cid) const;
+  };
+
+  bool operator==(const CID& other) const noexcept;
+  bool operator!=(const CID& other) const noexcept;
+
+  operator const uint8_t*() const;
+  operator const ngtcp2_cid&() const;
+  operator const ngtcp2_cid*() const;
+
+  // True if the CID length is at least kMinLength;
+  operator bool() const;
+  size_t length() const;
+
+  std::string ToString() const;
+
+  SET_NO_MEMORY_INFO()
+  SET_MEMORY_INFO_NAME(CID)
+  SET_SELF_SIZE(CID)
+
+  template <typename T>
+  using Map = std::unordered_map<CID, T, CID::Hash>;
+
+  // A CID::Factory, as the name suggests, is used to create new CIDs.
+  // Per https://datatracker.ietf.org/doc/draft-ietf-quic-load-balancers/, QUIC
+  // implementations MAY use the Connection ID associated with a QUIC session
+  // as a routing mechanism, with each CID instance securely encoding the
+  // routing information. By default, our implementation creates CIDs randomly
+  // but will allow user code to provide their own CID::Factory implementation.
+  class Factory;
+
+  static CID kInvalid;
+
+ private:
+  // The default constructor creates an empty, zero-length CID.
+  // Zero-length CIDs are not usable. We use them as a placeholder
+  // for a missing or empty CID value.
+  CID();
+
+  ngtcp2_cid cid_;
+  const ngtcp2_cid* ptr_;
+
+  friend struct Hash;
+};
+
+class CID::Factory {
+ public:
+  virtual ~Factory() = default;
+
+  // Generate a new CID. The length_hint must be between CID::kMinLength
+  // and CID::kMaxLength. The implementation can choose to ignore the length.
+  virtual CID Generate(size_t length_hint = CID::kMaxLength) const = 0;
+
+  // Generate a new CID into the given ngtcp2_cid. This variation of
+  // Generate should be used far less commonly. It is provided largely
+  // for a couple of internal cases.
+  virtual void GenerateInto(ngtcp2_cid* cid,
+                            size_t length_hint = CID::kMaxLength) const = 0;
+
+  // The default random CID generator instance.
+  static const Factory& random();
+
+  // TODO(@jasnell): This will soon also include additional implementations
+  // of CID::Factory that implement the QUIC Load Balancers spec.
+};
+
+}  // namespace quic
+}  // namespace node
+
+#endif  // HAVE_OPENSSL && NODE_OPENSSL_HAS_QUIC
+#endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS