Add 'lib/protocol/' from commit 'f91191218b192ace841c878f161832d19c09145a'

git-subtree-dir: lib/protocol
git-subtree-mainline: 5ecb8bdd8a
git-subtree-split: f91191218b

lib/protocol/fuzz.go

@@ -0,0 +1,70 @@
+// Copyright (C) 2015 The Protocol Authors.
+
+// +build gofuzz
+
+package protocol
+
+import (
+	"bytes"
+	"encoding/binary"
+	"encoding/hex"
+	"fmt"
+	"reflect"
+	"sync"
+)
+
+func Fuzz(data []byte) int {
+	// Regenerate the length, or we'll most commonly exit quickly due to an
+	// unexpected eof which is unintestering.
+	if len(data) > 8 {
+		binary.BigEndian.PutUint32(data[4:], uint32(len(data))-8)
+	}
+
+	// Setup a rawConnection we'll use to parse the message.
+	c := rawConnection{
+		cr:     &countingReader{Reader: bytes.NewReader(data)},
+		closed: make(chan struct{}),
+		pool: sync.Pool{
+			New: func() interface{} {
+				return make([]byte, BlockSize)
+			},
+		},
+	}
+
+	// Attempt to parse the message.
+	hdr, msg, err := c.readMessage()
+	if err != nil {
+		return 0
+	}
+
+	// If parsing worked, attempt to encode it again.
+	newBs, err := msg.AppendXDR(nil)
+	if err != nil {
+		panic("not encodable")
+	}
+
+	// Create an appriate header for the re-encoding.
+	newMsg := make([]byte, 8)
+	binary.BigEndian.PutUint32(newMsg, encodeHeader(hdr))
+	binary.BigEndian.PutUint32(newMsg[4:], uint32(len(newBs)))
+	newMsg = append(newMsg, newBs...)
+
+	// Use the rawConnection to parse the re-encoding.
+	c.cr = &countingReader{Reader: bytes.NewReader(newMsg)}
+	hdr2, msg2, err := c.readMessage()
+	if err != nil {
+		fmt.Println("Initial:\n" + hex.Dump(data))
+		fmt.Println("New:\n" + hex.Dump(newMsg))
+		panic("not parseable after re-encode: " + err.Error())
+	}
+
+	// Make sure the data is the same as it was before.
+	if hdr != hdr2 {
+		panic("headers differ")
+	}
+	if !reflect.DeepEqual(msg, msg2) {
+		panic("contents differ")
+	}
+
+	return 1
+}