From 69f4c5a7e9c731d76b3bedce112feb8ca8e6ffe0 Mon Sep 17 00:00:00 2001
From: Matt Joiner <anacrolix@gmail.com>
Date: Fri, 16 Sep 2016 12:13:06 +1000
Subject: [PATCH] Minor comments and test improvement

---
 config.go       |  5 +++--
 mse/mse.go      | 11 +++++++----
 mse/mse_test.go |  8 +++++++-
 3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/config.go b/config.go
index 9ea76416..8b180fdc 100644
--- a/config.go
+++ b/config.go
@@ -33,8 +33,9 @@ type Config struct {
 	DisableUTP bool
 	// For the bittorrent protocol.
 	DisableTCP bool `long:"disable-tcp"`
-	// Called to instantiate storage for each added torrent. Provided backends
-	// are in $REPO/data. If not set, the "file" implementation is used.
+	// Called to instantiate storage for each added torrent. Builtin backends
+	// are in the storage package. If not set, the "file" implementation is
+	// used.
 	DefaultStorage    storage.ClientImpl
 	DisableEncryption bool `long:"disable-encryption"`
 
diff --git a/mse/mse.go b/mse/mse.go
index 46b59a48..d366aa75 100644
--- a/mse/mse.go
+++ b/mse/mse.go
@@ -183,13 +183,14 @@ func newPadLen() int64 {
 	return ret
 }
 
+// Manages state for both initiating and receiving handshakes.
 type handshake struct {
 	conn   io.ReadWriter
 	s      [96]byte
-	initer bool
-	skeys  [][]byte
-	skey   []byte
-	ia     []byte // Initial payload. Only used by the initiator.
+	initer bool     // Whether we're initiating or receiving.
+	skeys  [][]byte // Skeys we'll accept if receiving.
+	skey   []byte   // Skey we're initiating with.
+	ia     []byte   // Initial payload. Only used by the initiator.
 
 	writeMu    sync.Mutex
 	writes     [][]byte
@@ -311,6 +312,8 @@ func suffixMatchLen(a, b []byte) int {
 	return 0
 }
 
+// Reads from r until b has been seen. Keeps the minimum amount of data in
+// memory.
 func readUntil(r io.Reader, b []byte) error {
 	b1 := make([]byte, len(b))
 	i := 0
diff --git a/mse/mse_test.go b/mse/mse_test.go
index d74dec97..6c279954 100644
--- a/mse/mse_test.go
+++ b/mse/mse_test.go
@@ -10,6 +10,7 @@ import (
 	"testing"
 
 	"github.com/bradfitz/iter"
+	"github.com/stretchr/testify/require"
 )
 
 func TestReadUntil(t *testing.T) {
@@ -117,5 +118,10 @@ func (tr *trackReader) Read(b []byte) (n int, err error) {
 
 func TestReceiveRandomData(t *testing.T) {
 	tr := trackReader{rand.Reader, 0}
-	ReceiveHandshake(readWriter{&tr, ioutil.Discard}, nil)
+	_, err := ReceiveHandshake(readWriter{&tr, ioutil.Discard}, nil)
+	// No skey matches
+	require.Error(t, err)
+	// Establishing S, and then reading the maximum padding for giving up on
+	// synchronizing.
+	require.EqualValues(t, 96+532, tr.n)
 }
-- 
2.44.0