package eth import ( "fmt" "math/big" "github.com/ethereum/go-ethereum/common" "github.com/ethereum/go-ethereum/core/types" "github.com/ethereum/go-ethereum/p2p" "gopkg.in/fatih/set.v0" ) type statusMsgData struct { ProtocolVersion uint32 NetworkId uint32 TD *big.Int CurrentBlock common.Hash GenesisBlock common.Hash } type getBlockHashesMsgData struct { Hash common.Hash Amount uint64 } type peer struct { *p2p.Peer rw p2p.MsgReadWriter protv, netid int currentHash common.Hash id string td *big.Int genesis, ourHash common.Hash ourTd *big.Int txHashes *set.Set blockHashes *set.Set } func newPeer(protv, netid int, genesis, currentHash common.Hash, td *big.Int, p *p2p.Peer, rw p2p.MsgReadWriter) *peer { id := p.ID() return &peer{ Peer: p, rw: rw, genesis: genesis, ourHash: currentHash, ourTd: td, protv: protv, netid: netid, id: fmt.Sprintf("%x", id[:8]), txHashes: set.New(), blockHashes: set.New(), } } // sendTransactions sends transactions to the peer and includes the hashes // in it's tx hash set for future reference. The tx hash will allow the // manager to check whether the peer has already received this particular // transaction func (p *peer) sendTransactions(txs types.Transactions) error { for _, tx := range txs { p.txHashes.Add(tx.Hash()) } return p2p.Send(p.rw, TxMsg, txs) } func (p *peer) sendBlockHashes(hashes []common.Hash) error { return p2p.Send(p.rw, BlockHashesMsg, hashes) } func (p *peer) sendBlocks(blocks []*types.Block) error { return p2p.Send(p.rw, BlocksMsg, blocks) } func (p *peer) requestHashes(from common.Hash) error { p.Debugf("fetching hashes (%d) %x...\n", maxHashes, from[0:4]) return p2p.Send(p.rw, GetBlockHashesMsg, getBlockHashesMsgData{from, maxHashes}) } func (p *peer) requestBlocks(hashes []common.Hash) error { p.Debugf("fetching %v blocks", len(hashes)) return p2p.Send(p.rw, GetBlocksMsg, hashes) } func (p *peer) handleStatus() error { errc := make(chan error, 1) go func() { errc <- p2p.Send(p.rw, StatusMsg, &statusMsgData{ ProtocolVersion: uint32(p.protv), NetworkId: uint32(p.netid), TD: p.ourTd, CurrentBlock: p.ourHash, GenesisBlock: p.genesis, }) }() // read and handle remote status msg, err := p.rw.ReadMsg() if err != nil { return err } if msg.Code != StatusMsg { return errResp(ErrNoStatusMsg, "first msg has code %x (!= %x)", msg.Code, StatusMsg) } if msg.Size > ProtocolMaxMsgSize { return errResp(ErrMsgTooLarge, "%v > %v", msg.Size, ProtocolMaxMsgSize) } var status statusMsgData if err := msg.Decode(&status); err != nil { return errResp(ErrDecode, "msg %v: %v", msg, err) } if status.GenesisBlock != p.genesis { return errResp(ErrGenesisBlockMismatch, "%x (!= %x)", status.GenesisBlock, p.genesis) } if int(status.NetworkId) != p.netid { return errResp(ErrNetworkIdMismatch, "%d (!= %d)", status.NetworkId, p.netid) } if int(status.ProtocolVersion) != p.protv { return errResp(ErrProtocolVersionMismatch, "%d (!= %d)", status.ProtocolVersion, p.protv) } // Set the total difficulty of the peer p.td = status.TD // set the best hash of the peer p.currentHash = status.CurrentBlock return <-errc }