cmd/devp2p: add eth protocol test suite (ethereum#21598)

This change adds a test framework for the "eth" protocol and some basic
tests. The tests can be run using the './devp2p rlpx eth-test' command.

cmd/devp2p/internal/ethtest/chain.go

@@ -0,0 +1,113 @@
+package ethtest
+
+import (
+ "compress/gzip"
+ "encoding/json"
+ "fmt"
+ "io"
+ "io/ioutil"
+ "math/big"
+ "os"
+ "strings"
+
+ "github.com/ethereum/go-ethereum/core"
+ "github.com/ethereum/go-ethereum/core/forkid"
+ "github.com/ethereum/go-ethereum/core/types"
+ "github.com/ethereum/go-ethereum/params"
+ "github.com/ethereum/go-ethereum/rlp"
+)
+
+type Chain struct {
+ blocks []*types.Block
+ chainConfig *params.ChainConfig
+}
+
+func (c *Chain) WriteTo(writer io.Writer) error {
+ for _, block := range c.blocks {
+ if err := rlp.Encode(writer, block); err != nil {
+ return err
+ }
+ }
+
+ return nil
+}
+
+// Len returns the length of the chain.
+func (c *Chain) Len() int {
+ return len(c.blocks)
+}
+
+// TD calculates the total difficulty of the chain.
+func (c *Chain) TD(height int) *big.Int { // TODO later on channge scheme so that the height is included in range
+ sum := big.NewInt(0)
+ for _, block := range c.blocks[:height] {
+ sum.Add(sum, block.Difficulty())
+ }
+ return sum
+}
+
+// ForkID gets the fork id of the chain.
+func (c *Chain) ForkID() forkid.ID {
+ return forkid.NewID(c.chainConfig, c.blocks[0].Hash(), uint64(c.Len()))
+}
+
+// Shorten returns a copy chain of a desired height from the imported
+func (c *Chain) Shorten(height int) *Chain {
+ blocks := make([]*types.Block, height)
+ copy(blocks, c.blocks[:height])
+
+ config := *c.chainConfig
+ return &Chain{
+ blocks: blocks,
+ chainConfig: &config,
+ }
+}
+
+// Head returns the chain head.
+func (c *Chain) Head() *types.Block {
+ return c.blocks[c.Len()-1]
+}
+
+// loadChain takes the given chain.rlp file, and decodes and returns
+// the blocks from the file.
+func loadChain(chainfile string, genesis string) (*Chain, error) {
+ // Open the file handle and potentially unwrap the gzip stream
+ fh, err := os.Open(chainfile)
+ if err != nil {
+ return nil, err
+ }
+ defer fh.Close()
+
+ var reader io.Reader = fh
+ if strings.HasSuffix(chainfile, ".gz") {
+ if reader, err = gzip.NewReader(reader); err != nil {
+ return nil, err
+ }
+ }
+ stream := rlp.NewStream(reader, 0)
+ var blocks []*types.Block
+ for i := 0; ; i++ {
+ var b types.Block
+ if err := stream.Decode(&b); err == io.EOF {
+ break
+ } else if err != nil {
+ return nil, fmt.Errorf("at block %d: %v", i, err)
+ }
+ blocks = append(blocks, &b)
+ }
+
+ // Open the file handle and potentially unwrap the gzip stream
+ chainConfig, err := ioutil.ReadFile(genesis)
+ if err != nil {
+ return nil, err
+ }
+ var gen core.Genesis
+ if err := json.Unmarshal(chainConfig, &gen); err != nil {
+ return nil, err
+ }
+
+ return &Chain{
+ blocks: blocks,
+ chainConfig: gen.Config,
+ }, nil
+}