From 9e1d9bff3b18cfa09ba96cd027fa653daae10816 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?P=C3=A9ter=20Szil=C3=A1gyi?= Date: Thu, 5 Nov 2015 23:57:57 +0200 Subject: node: customizable protocol and service stacks --- node/config.go | 171 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 171 insertions(+) create mode 100644 node/config.go (limited to 'node/config.go') diff --git a/node/config.go b/node/config.go new file mode 100644 index 000000000..93f0ba79d --- /dev/null +++ b/node/config.go @@ -0,0 +1,171 @@ +// Copyright 2015 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 . + +package node + +import ( + "crypto/ecdsa" + "encoding/json" + "io/ioutil" + "net" + "os" + "path/filepath" + + "github.com/ethereum/go-ethereum/crypto" + "github.com/ethereum/go-ethereum/logger" + "github.com/ethereum/go-ethereum/logger/glog" + "github.com/ethereum/go-ethereum/p2p/discover" + "github.com/ethereum/go-ethereum/p2p/nat" +) + +var ( + datadirPrivateKey = "nodekey" // Path within the datadir to the node's private key + datadirStaticNodes = "static-nodes.json" // Path within the datadir to the static node list + datadirTrustedNodes = "trusted-nodes.json" // Path within the datadir to the trusted node list + datadirNodeDatabase = "nodes" // Path within the datadir to store the node infos +) + +// Config represents a small collection of configuration values to fine tune the +// P2P network layer of a protocol stack. These values can be further extended by +// all registered services. +type Config struct { + // DataDir is the file system folder the node should use for any data storage + // requirements. The configured data directory will not be directly shared with + // registered services, instead those can use utility methods to create/access + // databases or flat files. This enables ephemeral nodes which can fully reside + // in memory. + DataDir string + + // This field should be a valid secp256k1 private key that will be used for both + // remote peer identification as well as network traffic encryption. If no key + // is configured, the preset one is loaded from the data dir, generating it if + // needed. + PrivateKey *ecdsa.PrivateKey + + // Name sets the node name of this server. Use common.MakeName to create a name + // that follows existing conventions. + Name string + + // NoDiscovery specifies whether the peer discovery mechanism should be started + // or not. Disabling is usually useful for protocol debugging (manual topology). + NoDiscovery bool + + // Bootstrap nodes used to establish connectivity with the rest of the network. + BootstrapNodes []*discover.Node + + // Network interface address on which the node should listen for inbound peers. + ListenAddr string + + // If set to a non-nil value, the given NAT port mapper is used to make the + // listening port available to the Internet. + NAT nat.Interface + + // If Dialer is set to a non-nil value, the given Dialer is used to dial outbound + // peer connections. + Dialer *net.Dialer + + // If NoDial is true, the node will not dial any peers. + NoDial bool + + // MaxPeers is the maximum number of peers that can be connected. If this is + // set to zero, then only the configured static and trusted peers can connect. + MaxPeers int + + // MaxPendingPeers is the maximum number of peers that can be pending in the + // handshake phase, counted separately for inbound and outbound connections. + // Zero defaults to preset values. + MaxPendingPeers int +} + +// NodeKey retrieves the currently configured private key of the node, checking +// first any manually set key, falling back to the one found in the configured +// data folder. If no key can be found, a new one is generated. +func (c *Config) NodeKey() *ecdsa.PrivateKey { + // Use any specifically configured key + if c.PrivateKey != nil { + return c.PrivateKey + } + // Generate ephemeral key if no datadir is being used + if c.DataDir == "" { + key, err := crypto.GenerateKey() + if err != nil { + glog.Fatalf("Failed to generate ephemeral node key: %v", err) + } + return key + } + // Fall back to persistent key from the data directory + keyfile := filepath.Join(c.DataDir, datadirPrivateKey) + if key, err := crypto.LoadECDSA(keyfile); err == nil { + return key + } + // No persistent key found, generate and store a new one + key, err := crypto.GenerateKey() + if err != nil { + glog.Fatalf("Failed to generate node key: %v", err) + } + if err := crypto.SaveECDSA(keyfile, key); err != nil { + glog.V(logger.Error).Infof("Failed to persist node key: %v", err) + } + return key +} + +// StaticNodes returns a list of node enode URLs configured as static nodes. +func (c *Config) StaticNodes() []*discover.Node { + return c.parsePersistentNodes(datadirStaticNodes) +} + +// TrusterNodes returns a list of node enode URLs configured as trusted nodes. +func (c *Config) TrusterNodes() []*discover.Node { + return c.parsePersistentNodes(datadirTrustedNodes) +} + +// parsePersistentNodes parses a list of discovery node URLs loaded from a .json +// file from within the data directory. +func (c *Config) parsePersistentNodes(file string) []*discover.Node { + // Short circuit if no node config is present + if c.DataDir == "" { + return nil + } + path := filepath.Join(c.DataDir, file) + if _, err := os.Stat(path); err != nil { + return nil + } + // Load the nodes from the config file + blob, err := ioutil.ReadFile(path) + if err != nil { + glog.V(logger.Error).Infof("Failed to access nodes: %v", err) + return nil + } + nodelist := []string{} + if err := json.Unmarshal(blob, &nodelist); err != nil { + glog.V(logger.Error).Infof("Failed to load nodes: %v", err) + return nil + } + // Interpret the list as a discovery node array + var nodes []*discover.Node + for _, url := range nodelist { + if url == "" { + continue + } + node, err := discover.ParseNode(url) + if err != nil { + glog.V(logger.Error).Infof("Node URL %s: %v\n", url, err) + continue + } + nodes = append(nodes, node) + } + return nodes +} -- cgit v1.2.3