Add negative tests for MsgGetHeaders.

This commit adds tests for the error paths when encoded and decoding
MsgHeaders.   Also, while here modify the casing of the local vars to be
consistent.

msggetheaders_test.go

@@ -8,6 +8,7 @@ import (
 	"bytes"
 	"github.com/conformal/btcwire"
 	"github.com/davecgh/go-spew/spew"
+	"io"
 	"reflect"
 	"testing"
 )
@@ -70,7 +71,9 @@ func TestGetHeaders(t *testing.T) {
 // TestGetHeadersWire tests the MsgGetHeaders wire encode and decode for various
 // numbers of block locator hashes and protocol versions.
 func TestGetHeadersWire(t *testing.T) {
-	// Set protocol inside getheaders message.
+	// Set protocol inside getheaders message.  Use protocol version 60002
+	// specifically here instead of the latest because the test data is
+	// using bytes encoded with that protocol version.
 	pver := uint32(60002)
 
 	// Block 99499 hash.
@@ -95,9 +98,9 @@ func TestGetHeadersWire(t *testing.T) {
 	}
 
 	// MsgGetHeaders message with no block locators or stop hash.
-	NoLocators := btcwire.NewMsgGetHeaders()
+	noLocators := btcwire.NewMsgGetHeaders()
-	NoLocators.ProtocolVersion = pver
+	noLocators.ProtocolVersion = pver
-	NoLocatorsEncoded := []byte{
+	noLocatorsEncoded := []byte{
 		0x62, 0xea, 0x00, 0x00, // Protocol version 60002
 		0x00, // Varint for number of block locator hashes
 		0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
@@ -107,12 +110,12 @@ func TestGetHeadersWire(t *testing.T) {
 	}
 
 	// MsgGetHeaders message with multiple block locators and a stop hash.
-	MultiLocators := btcwire.NewMsgGetHeaders()
+	multiLocators := btcwire.NewMsgGetHeaders()
-	MultiLocators.ProtocolVersion = pver
+	multiLocators.ProtocolVersion = pver
-	MultiLocators.HashStop = *hashStop
+	multiLocators.HashStop = *hashStop
-	MultiLocators.AddBlockLocatorHash(hashLocator2)
+	multiLocators.AddBlockLocatorHash(hashLocator2)
-	MultiLocators.AddBlockLocatorHash(hashLocator)
+	multiLocators.AddBlockLocatorHash(hashLocator)
-	MultiLocatorsEncoded := []byte{
+	multiLocatorsEncoded := []byte{
 		0x62, 0xea, 0x00, 0x00, // Protocol version 60002
 		0x02, // Varint for number of block locator hashes
 		0xe0, 0xde, 0x06, 0x44, 0x68, 0x13, 0x2c, 0x63,
@@ -137,81 +140,81 @@ func TestGetHeadersWire(t *testing.T) {
 	}{
 		// Latest protocol version with no block locators.
 		{
-			NoLocators,
+			noLocators,
-			NoLocators,
+			noLocators,
-			NoLocatorsEncoded,
+			noLocatorsEncoded,
 			btcwire.ProtocolVersion,
 		},
 
 		// Latest protocol version with multiple block locators.
 		{
-			MultiLocators,
+			multiLocators,
-			MultiLocators,
+			multiLocators,
-			MultiLocatorsEncoded,
+			multiLocatorsEncoded,
 			btcwire.ProtocolVersion,
 		},
 
 		// Protocol version BIP0035Version with no block locators.
 		{
-			NoLocators,
+			noLocators,
-			NoLocators,
+			noLocators,
-			NoLocatorsEncoded,
+			noLocatorsEncoded,
 			btcwire.BIP0035Version,
 		},
 
 		// Protocol version BIP0035Version with multiple block locators.
 		{
-			MultiLocators,
+			multiLocators,
-			MultiLocators,
+			multiLocators,
-			MultiLocatorsEncoded,
+			multiLocatorsEncoded,
 			btcwire.BIP0035Version,
 		},
 
 		// Protocol version BIP0031Version with no block locators.
 		{
-			NoLocators,
+			noLocators,
-			NoLocators,
+			noLocators,
-			NoLocatorsEncoded,
+			noLocatorsEncoded,
 			btcwire.BIP0031Version,
 		},
 
 		// Protocol version BIP0031Versionwith multiple block locators.
 		{
-			MultiLocators,
+			multiLocators,
-			MultiLocators,
+			multiLocators,
-			MultiLocatorsEncoded,
+			multiLocatorsEncoded,
 			btcwire.BIP0031Version,
 		},
 
 		// Protocol version NetAddressTimeVersion with no block locators.
 		{
-			NoLocators,
+			noLocators,
-			NoLocators,
+			noLocators,
-			NoLocatorsEncoded,
+			noLocatorsEncoded,
 			btcwire.NetAddressTimeVersion,
 		},
 
 		// Protocol version NetAddressTimeVersion multiple block locators.
 		{
-			MultiLocators,
+			multiLocators,
-			MultiLocators,
+			multiLocators,
-			MultiLocatorsEncoded,
+			multiLocatorsEncoded,
 			btcwire.NetAddressTimeVersion,
 		},
 
 		// Protocol version MultipleAddressVersion with no block locators.
 		{
-			NoLocators,
+			noLocators,
-			NoLocators,
+			noLocators,
-			NoLocatorsEncoded,
+			noLocatorsEncoded,
 			btcwire.MultipleAddressVersion,
 		},
 
 		// Protocol version MultipleAddressVersion multiple block locators.
 		{
-			MultiLocators,
+			multiLocators,
-			MultiLocators,
+			multiLocators,
-			MultiLocatorsEncoded,
+			multiLocatorsEncoded,
 			btcwire.MultipleAddressVersion,
 		},
 	}
@@ -246,3 +249,133 @@ func TestGetHeadersWire(t *testing.T) {
 		}
 	}
 }
+
+// TestGetHeadersWireErrors performs negative tests against wire encode and
+// decode of MsgGetHeaders to confirm error paths work correctly.
+func TestGetHeadersWireErrors(t *testing.T) {
+	// Set protocol inside getheaders message.  Use protocol version 60002
+	// specifically here instead of the latest because the test data is
+	// using bytes encoded with that protocol version.
+	pver := uint32(60002)
+	btcwireErr := &btcwire.MessageError{}
+
+	// Block 99499 hash.
+	hashStr := "2710f40c87ec93d010a6fd95f42c59a2cbacc60b18cf6b7957535"
+	hashLocator, err := btcwire.NewShaHashFromStr(hashStr)
+	if err != nil {
+		t.Errorf("NewShaHashFromStr: %v", err)
+	}
+
+	// Block 99500 hash.
+	hashStr = "2e7ad7b9eef9479e4aabc65cb831269cc20d2632c13684406dee0"
+	hashLocator2, err := btcwire.NewShaHashFromStr(hashStr)
+	if err != nil {
+		t.Errorf("NewShaHashFromStr: %v", err)
+	}
+
+	// Block 100000 hash.
+	hashStr = "3ba27aa200b1cecaad478d2b00432346c3f1f3986da1afd33e506"
+	hashStop, err := btcwire.NewShaHashFromStr(hashStr)
+	if err != nil {
+		t.Errorf("NewShaHashFromStr: %v", err)
+	}
+
+	// MsgGetHeaders message with multiple block locators and a stop hash.
+	baseGetHeaders := btcwire.NewMsgGetHeaders()
+	baseGetHeaders.ProtocolVersion = pver
+	baseGetHeaders.HashStop = *hashStop
+	baseGetHeaders.AddBlockLocatorHash(hashLocator2)
+	baseGetHeaders.AddBlockLocatorHash(hashLocator)
+	baseGetHeadersEncoded := []byte{
+		0x62, 0xea, 0x00, 0x00, // Protocol version 60002
+		0x02, // Varint for number of block locator hashes
+		0xe0, 0xde, 0x06, 0x44, 0x68, 0x13, 0x2c, 0x63,
+		0xd2, 0x20, 0xcc, 0x69, 0x12, 0x83, 0xcb, 0x65,
+		0xbc, 0xaa, 0xe4, 0x79, 0x94, 0xef, 0x9e, 0x7b,
+		0xad, 0xe7, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, // Block 99500 hash
+		0x35, 0x75, 0x95, 0xb7, 0xf6, 0x8c, 0xb1, 0x60,
+		0xcc, 0xba, 0x2c, 0x9a, 0xc5, 0x42, 0x5f, 0xd9,
+		0x6f, 0x0a, 0x01, 0x3d, 0xc9, 0x7e, 0xc8, 0x40,
+		0x0f, 0x71, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, // Block 99499 hash
+		0x06, 0xe5, 0x33, 0xfd, 0x1a, 0xda, 0x86, 0x39,
+		0x1f, 0x3f, 0x6c, 0x34, 0x32, 0x04, 0xb0, 0xd2,
+		0x78, 0xd4, 0xaa, 0xec, 0x1c, 0x0b, 0x20, 0xaa,
+		0x27, 0xba, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, // Hash stop
+	}
+
+	// Message that forces an error by having more than the max allowed
+	// block locator hashes.
+	maxGetHeaders := btcwire.NewMsgGetHeaders()
+	for i := 0; i < btcwire.MaxBlockLocatorsPerMsg; i++ {
+		maxGetHeaders.AddBlockLocatorHash(&btcwire.GenesisHash)
+	}
+	maxGetHeaders.BlockLocatorHashes = append(maxGetHeaders.BlockLocatorHashes,
+		&btcwire.GenesisHash)
+	//maxGetHeaders.InvList = append(maxGetData.InvList, iv)
+	maxGetHeadersEncoded := []byte{
+		0x62, 0xea, 0x00, 0x00, // Protocol version 60002
+		0xfd, 0xf5, 0x01, // Varint for number of block loc hashes (501)
+	}
+
+	tests := []struct {
+		in       *btcwire.MsgGetHeaders // Value to encode
+		buf      []byte                 // Wire encoding
+		pver     uint32                 // Protocol version for wire encoding
+		max      int                    // Max size of fixed buffer to induce errors
+		writeErr error                  // Expected write error
+		readErr  error                  // Expected read error
+	}{
+		// Force error in protocol version.
+		{baseGetHeaders, baseGetHeadersEncoded, pver, 0, io.ErrShortWrite, io.EOF},
+		// Force error in block locator hash count.
+		{baseGetHeaders, baseGetHeadersEncoded, pver, 4, io.ErrShortWrite, io.EOF},
+		// Force error in block locator hashes.
+		{baseGetHeaders, baseGetHeadersEncoded, pver, 5, io.ErrShortWrite, io.EOF},
+		// Force error in stop hash.
+		{baseGetHeaders, baseGetHeadersEncoded, pver, 69, io.ErrShortWrite, io.EOF},
+		// Force error with greater than max block locator hashes.
+		{maxGetHeaders, maxGetHeadersEncoded, pver, 7, btcwireErr, btcwireErr},
+	}
+
+	t.Logf("Running %d tests", len(tests))
+	for i, test := range tests {
+		// Encode to wire format.
+		w := newFixedWriter(test.max)
+		err := test.in.BtcEncode(w, test.pver)
+		if reflect.TypeOf(err) != reflect.TypeOf(test.writeErr) {
+			t.Errorf("BtcEncode #%d wrong error got: %v, want: %v",
+				i, err, test.writeErr)
+			continue
+		}
+
+		// For errors which are not of type btcwire.MessageError, check
+		// them for equality.
+		if _, ok := err.(*btcwire.MessageError); !ok {
+			if err != test.writeErr {
+				t.Errorf("BtcEncode #%d wrong error got: %v, "+
+					"want: %v", i, err, test.writeErr)
+				continue
+			}
+		}
+
+		// Decode from wire format.
+		var msg btcwire.MsgGetHeaders
+		r := newFixedReader(test.max, test.buf)
+		err = msg.BtcDecode(r, test.pver)
+		if reflect.TypeOf(err) != reflect.TypeOf(test.readErr) {
+			t.Errorf("BtcDecode #%d wrong error got: %v, want: %v",
+				i, err, test.readErr)
+			continue
+		}
+
+		// For errors which are not of type btcwire.MessageError, check
+		// them for equality.
+		if _, ok := err.(*btcwire.MessageError); !ok {
+			if err != test.readErr {
+				t.Errorf("BtcEncode #%d wrong error got: %v, "+
+					"want: %v", i, err, test.readErr)
+				continue
+			}
+		}
+	}
+}