les: fix crasher in NodeInfo when running as server (#17419)

* les: fix crasher in NodeInfo when running as server

The ProtocolManager computes CHT and Bloom trie roots by asking the
indexers for their current head. It tried to get the indexers from
LesOdr, but no LesOdr instance is created in server mode.

Attempt to fix this by moving the indexers, protocol creation and
NodeInfo to a new lesCommons struct which is embedded into both server
and client.

All this setup code should really be cleaned up, but this is just a
hotfix so we have to do that some other time.

* les: fix commons protocol maker

1 files changed, 106 insertions, 0 deletions

diff --git a/les/commons.go b/les/commons.go
new file mode 100644
index 000000000..251b7a583
--- /dev/null
+++ b/les/commons.go
@@ -0,0 +1,106 @@
+// 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
+	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, _, sectionHead := c.chtIndexer.Sections()
+	sections2, _, sectionHead2 := c.bloomTrieIndexer.Sections()
+	if sections2 < sections {
+		sections = sections2
+		sectionHead = sectionHead2
+	}
+	if sections > 0 {
+		sectionIndex := sections - 1
+		cht = light.TrustedCheckpoint{
+			SectionIdx:  sectionIndex,
+			SectionHead: sectionHead,
+			CHTRoot:     light.GetChtRoot(c.chainDb, sectionIndex, sectionHead),
+			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,
+	}
+}