cmd/devp2p/internal/ethtest: improve eth test suite (ethereum#21615)

This fixes issues with the protocol handshake and status exchange
and adds support for responding to GetBlockHeaders requests.

cmd/devp2p/internal/ethtest/chain.go

@@ -1,3 +1,19 @@
+// Copyright 2020 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
 package ethtest
 
 import (
@@ -68,6 +84,43 @@ func (c *Chain) Head() *types.Block {
 	return c.blocks[c.Len()-1]
 }
 
+func (c *Chain) GetHeaders(req GetBlockHeaders) (BlockHeaders, error) {
+	if req.Amount < 1 {
+		return nil, fmt.Errorf("no block headers requested")
+	}
+
+	headers := make(BlockHeaders, req.Amount)
+	var blockNumber uint64
+
+	// range over blocks to check if our chain has the requested header
+	for _, block := range c.blocks {
+		if block.Hash() == req.Origin.Hash || block.Number().Uint64() == req.Origin.Number {
+			headers[0] = block.Header()
+			blockNumber = block.Number().Uint64()
+		}
+	}
+	if headers[0] == nil {
+		return nil, fmt.Errorf("no headers found for given origin number %v, hash %v", req.Origin.Number, req.Origin.Hash)
+	}
+
+	if req.Reverse {
+		for i := 1; i < int(req.Amount); i++ {
+			blockNumber -= (1 - req.Skip)
+			headers[i] = c.blocks[blockNumber].Header()
+
+		}
+
+		return headers, nil
+	}
+
+	for i := 1; i < int(req.Amount); i++ {
+		blockNumber += (1 + req.Skip)
+		headers[i] = c.blocks[blockNumber].Header()
+	}
+
+	return headers, nil
+}
+
 // loadChain takes the given chain.rlp file, and decodes and returns
 // the blocks from the file.
 func loadChain(chainfile string, genesis string) (*Chain, error) {

cmd/devp2p/internal/ethtest/chain_test.go

@@ -0,0 +1,150 @@
+// Copyright 2020 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package ethtest
+
+import (
+	"path/filepath"
+	"strconv"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/stretchr/testify/assert"
+)
+
+// TestEthProtocolNegotiation tests whether the test suite
+// can negotiate the highest eth protocol in a status message exchange
+func TestEthProtocolNegotiation(t *testing.T) {
+	var tests = []struct {
+		conn     *Conn
+		caps     []p2p.Cap
+		expected uint32
+	}{
+		{
+			conn: &Conn{},
+			caps: []p2p.Cap{
+				{Name: "eth", Version: 63},
+				{Name: "eth", Version: 64},
+				{Name: "eth", Version: 65},
+			},
+			expected: uint32(65),
+		},
+		{
+			conn: &Conn{},
+			caps: []p2p.Cap{
+				{Name: "eth", Version: 0},
+				{Name: "eth", Version: 89},
+				{Name: "eth", Version: 65},
+			},
+			expected: uint32(65),
+		},
+		{
+			conn: &Conn{},
+			caps: []p2p.Cap{
+				{Name: "eth", Version: 63},
+				{Name: "eth", Version: 64},
+				{Name: "wrongProto", Version: 65},
+			},
+			expected: uint32(64),
+		},
+	}
+
+	for i, tt := range tests {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
+			tt.conn.negotiateEthProtocol(tt.caps)
+			assert.Equal(t, tt.expected, uint32(tt.conn.ethProtocolVersion))
+		})
+	}
+}
+
+// TestChain_GetHeaders tests whether the test suite can correctly
+// respond to a GetBlockHeaders request from a node.
+func TestChain_GetHeaders(t *testing.T) {
+	chainFile, err := filepath.Abs("./testdata/chain.rlp.gz")
+	if err != nil {
+		t.Fatal(err)
+	}
+	genesisFile, err := filepath.Abs("./testdata/genesis.json")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	chain, err := loadChain(chainFile, genesisFile)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	var tests = []struct {
+		req      GetBlockHeaders
+		expected BlockHeaders
+	}{
+		{
+			req: GetBlockHeaders{
+				Origin: hashOrNumber{
+					Number: uint64(2),
+				},
+				Amount:  uint64(5),
+				Skip:    1,
+				Reverse: false,
+			},
+			expected: BlockHeaders{
+				chain.blocks[2].Header(),
+				chain.blocks[4].Header(),
+				chain.blocks[6].Header(),
+				chain.blocks[8].Header(),
+				chain.blocks[10].Header(),
+			},
+		},
+		{
+			req: GetBlockHeaders{
+				Origin: hashOrNumber{
+					Number: uint64(chain.Len() - 1),
+				},
+				Amount:  uint64(3),
+				Skip:    0,
+				Reverse: true,
+			},
+			expected: BlockHeaders{
+				chain.blocks[chain.Len()-1].Header(),
+				chain.blocks[chain.Len()-2].Header(),
+				chain.blocks[chain.Len()-3].Header(),
+			},
+		},
+		{
+			req: GetBlockHeaders{
+				Origin: hashOrNumber{
+					Hash: chain.Head().Hash(),
+				},
+				Amount:  uint64(1),
+				Skip:    0,
+				Reverse: false,
+			},
+			expected: BlockHeaders{
+				chain.Head().Header(),
+			},
+		},
+	}
+
+	for i, tt := range tests {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
+			headers, err := chain.GetHeaders(tt.req)
+			if err != nil {
+				t.Fatal(err)
+			}
+			assert.Equal(t, headers, tt.expected)
+		})
+	}
+}