path: root/les/commons.go

// Copyright 2018 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 les

import (
    "fmt"
    "math/big"

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/core"
    "github.com/ethereum/go-ethereum/eth"
    "github.com/ethereum/go-ethereum/ethdb"
    "github.com/ethereum/go-ethereum/light"
    "github.com/ethereum/go-ethereum/p2p"
    "github.com/ethereum/go-ethereum/p2p/discover"
    "github.com/ethereum/go-ethereum/params"
)

// lesCommons contains fields needed by both server and client.
type lesCommons struct {
    config                       *eth.Config
    iConfig                      *light.IndexerConfig
    chainDb                      ethdb.Database
    protocolManager              *ProtocolManager
    chtIndexer, bloomTrieIndexer *core.ChainIndexer
}

// NodeInfo represents a short summary of the Ethereum sub-protocol metadata
// known about the host peer.
type NodeInfo struct {
    Network    uint64                  `json:"network"`    // Ethereum network ID (1=Frontier, 2=Morden, Ropsten=3, Rinkeby=4)
    Difficulty *big.Int                `json:"difficulty"` // Total difficulty of the host's blockchain
    Genesis    common.Hash             `json:"genesis"`    // SHA3 hash of the host's genesis block
    Config     *params.ChainConfig     `json:"config"`     // Chain configuration for the fork rules
    Head       common.Hash             `json:"head"`       // SHA3 hash of the host's best owned block
    CHT        light.TrustedCheckpoint `json:"cht"`        // Trused CHT checkpoint for fast catchup
}

// makeProtocols creates protocol descriptors for the given LES versions.
func (c *lesCommons) makeProtocols(versions []uint) []p2p.Protocol {
    protos := make([]p2p.Protocol, len(versions))
    for i, version := range versions {
        version := version
        protos[i] = p2p.Protocol{
            Name:     "les",
            Version:  version,
            Length:   ProtocolLengths[version],
            NodeInfo: c.nodeInfo,
            Run: func(p *p2p.Peer, rw p2p.MsgReadWriter) error {
                return c.protocolManager.runPeer(version, p, rw)
            },
            PeerInfo: func(id discover.NodeID) interface{} {
                if p := c.protocolManager.peers.Peer(fmt.Sprintf("%x", id[:8])); p != nil {
                    return p.Info()
                }
                return nil
            },
        }
    }
    return protos
}

// nodeInfo retrieves some protocol metadata about the running host node.
func (c *lesCommons) nodeInfo() interface{} {
    var cht light.TrustedCheckpoint
    sections, _, _ := c.chtIndexer.Sections()
    sections2, _, _ := c.bloomTrieIndexer.Sections()

    if !c.protocolManager.lightSync {
        // convert to client section size if running in server mode
        sections /= c.iConfig.PairChtSize / c.iConfig.ChtSize
    }

    if sections2 < sections {
        sections = sections2
    }
    if sections > 0 {
        sectionIndex := sections - 1
        sectionHead := c.bloomTrieIndexer.SectionHead(sectionIndex)
        var chtRoot common.Hash
        if c.protocolManager.lightSync {
            chtRoot = light.GetChtRoot(c.chainDb, sectionIndex, sectionHead)
        } else {
            idxV2 := (sectionIndex+1)*c.iConfig.PairChtSize/c.iConfig.ChtSize - 1
            chtRoot = light.GetChtRoot(c.chainDb, idxV2, sectionHead)
        }
        cht = light.TrustedCheckpoint{
            SectionIdx:  sectionIndex,
            SectionHead: sectionHead,
            CHTRoot:     chtRoot,
            BloomRoot:   light.GetBloomTrieRoot(c.chainDb, sectionIndex, sectionHead),
        }
    }

    chain := c.protocolManager.blockchain
    head := chain.CurrentHeader()
    hash := head.Hash()
    return &NodeInfo{
        Network:    c.config.NetworkId,
        Difficulty: chain.GetTd(hash, head.Number.Uint64()),
        Genesis:    chain.Genesis().Hash(),
        Config:     chain.Config(),
        Head:       chain.CurrentHeader().Hash(),
        CHT:        cht,
    }
}