slight refactor

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

internal/outpost/radius/eap/tls/buff_conn.go

@@ -0,0 +1,92 @@
+package tls
+
+import (
+	"bytes"
+	"context"
+	"net"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+)
+
+type BuffConn struct {
+	reader *bytes.Buffer
+	writer *bytes.Buffer
+
+	ctx context.Context
+
+	expectedWriterByteCount int
+	writtenByteCount        int
+}
+
+func NewBuffConn(initialData []byte, ctx context.Context) *BuffConn {
+	c := &BuffConn{
+		reader: bytes.NewBuffer(initialData),
+		writer: bytes.NewBuffer([]byte{}),
+		ctx:    ctx,
+	}
+	return c
+}
+
+func (conn BuffConn) OutboundData() []byte {
+	for {
+		// TODO cancel with conn.ctx
+		b := conn.writer.Bytes()
+		if len(b) < 1 {
+			log.Debug("TLS(buffcon): Attempted retrieve from empty buffer, stalling...")
+			time.Sleep(1 * time.Second)
+			continue
+		}
+		return b
+	}
+}
+
+func (conn *BuffConn) UpdateData(data []byte) {
+	conn.reader.Write(data)
+	conn.writtenByteCount += len(data)
+	log.Debugf("TLS(buffcon): Appending new data %d (total %d, expecting %d)", len(data), conn.writtenByteCount, conn.expectedWriterByteCount)
+}
+
+func (conn BuffConn) NeedsMoreData() bool {
+	if conn.expectedWriterByteCount > 0 {
+		return conn.reader.Len() < int(conn.expectedWriterByteCount)
+	}
+	return false
+}
+
+func (conn *BuffConn) Read(p []byte) (int, error) {
+	for {
+		// TODO cancel with conn.ctx
+		n, err := conn.reader.Read(p)
+		if n == 0 {
+			log.Debugf("TLS(buffcon): Attempted read %d from empty buffer, stalling...", len(p))
+			time.Sleep(100 * time.Millisecond)
+			continue
+		}
+		if conn.expectedWriterByteCount > 0 && conn.writtenByteCount < int(conn.expectedWriterByteCount) {
+			log.Debugf("TLS(buffcon): Attempted read %d while waiting for bytes %d, stalling...", len(p), conn.expectedWriterByteCount-conn.reader.Len())
+			time.Sleep(100 * time.Millisecond)
+			continue
+		}
+		if conn.expectedWriterByteCount > 0 && conn.writtenByteCount == int(conn.expectedWriterByteCount) {
+			conn.expectedWriterByteCount = 0
+		}
+		if conn.reader.Len() == 0 {
+			conn.writtenByteCount = 0
+		}
+		log.Debugf("TLS(buffcon): Read: %d from %d", len(p), n)
+		return n, err
+	}
+}
+
+func (conn BuffConn) Write(p []byte) (int, error) {
+	log.Debugf("TLS(buffcon): Write: %d", len(p))
+	return conn.writer.Write(p)
+}
+
+func (conn BuffConn) Close() error                       { return nil }
+func (conn BuffConn) LocalAddr() net.Addr                { return nil }
+func (conn BuffConn) RemoteAddr() net.Addr               { return nil }
+func (conn BuffConn) SetDeadline(t time.Time) error      { return nil }
+func (conn BuffConn) SetReadDeadline(t time.Time) error  { return nil }
+func (conn BuffConn) SetWriteDeadline(t time.Time) error { return nil }