quic: capture received connection_close details

Fixes: #86

Author: jasnell

src/node_quic_session.cc

@@ -1868,6 +1868,7 @@ bool QuicSession::Receive(
     // If processing the packet puts us into draining period, there's
     // absolutely nothing left for us to do except silently close
     // and destroy this QuicSession.
+    GetConnectionCloseInfo();
     SilentClose();
     return true;
   } else {
@@ -1893,6 +1894,14 @@ bool QuicSession::ReceiveClientInitial(const ngtcp2_cid* dcid) {
          initial_connection_close_ == NGTCP2_NO_ERROR;
 }
 
+// Captures the error code and family information from a received
+// connection close frame.
+void QuicSession::GetConnectionCloseInfo() {
+  ngtcp2_connection_close_error_code close_code;
+  ngtcp2_conn_get_connection_close_error_code(Connection(), &close_code);
+  SetLastError(QuicError(close_code));
+}
+
 bool QuicSession::ReceivePacket(
     ngtcp2_path* path,
     const uint8_t* data,

src/node_quic_session.h

@@ -925,6 +925,7 @@ class QuicSession : public AsyncWrap,
   void ExtendMaxStreamsRemoteUni(uint64_t max_streams);
   void ExtendMaxStreamsRemoteBidi(uint64_t max_streams);
   int GetNewConnectionID(ngtcp2_cid* cid, uint8_t* token, size_t cidlen);
+  void GetConnectionCloseInfo();
   void HandshakeCompleted();
   void PathValidation(
     const ngtcp2_path* path,

src/node_quic_util-inl.h

@@ -185,6 +185,21 @@ QuicError::QuicError(
   }
 }
 
+QuicError::QuicError(ngtcp2_connection_close_error_code ccec) :
+    code(ccec.error_code), family(QUIC_ERROR_SESSION) {
+  switch (ccec.type) {
+    case NGTCP2_CONNECTION_CLOSE_ERROR_CODE_TYPE_APPLICATION:
+      family = QUIC_ERROR_APPLICATION;
+      break;
+    case NGTCP2_CONNECTION_CLOSE_ERROR_CODE_TYPE_TRANSPORT:
+      if (code & NGTCP2_CRYPTO_ERROR)
+        family = QUIC_ERROR_CRYPTO;
+      break;
+    default:
+      UNREACHABLE();
+  }
+}
+
 QuicError::QuicError(
   Environment* env,
   v8::Local<v8::Value> codeArg,

src/node_quic_util.h

@@ -85,6 +85,7 @@ struct QuicError {
   inline QuicError(
       int32_t family_ = QUIC_ERROR_SESSION,
       uint64_t code_ = NGTCP2_NO_ERROR);
+  inline QuicError(ngtcp2_connection_close_error_code code);
   inline QuicError(
       Environment* env,
       v8::Local<v8::Value> codeArg,