path: root/node/config.go

// Copyright 2014 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 node

import (
    "crypto/ecdsa"
    "fmt"
    "io/ioutil"
    "os"
    "path/filepath"
    "runtime"
    "strings"

    "github.com/ethereum/go-ethereum/accounts"
    "github.com/ethereum/go-ethereum/accounts/keystore"
    "github.com/ethereum/go-ethereum/accounts/usbwallet"
    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/crypto"
    "github.com/ethereum/go-ethereum/log"
    "github.com/ethereum/go-ethereum/p2p"
    "github.com/ethereum/go-ethereum/p2p/discover"
)

const (
    datadirPrivateKey      = "nodekey"            // Path within the datadir to the node's private key
    datadirDefaultKeyStore = "keystore"           // Path within the datadir to the keystore
    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 {
    // Name sets the instance name of the node. It must not contain the / character and is
    // used in the devp2p node identifier. The instance name of geth is "geth". If no
    // value is specified, the basename of the current executable is used.
    Name string `toml:"-"`

    // UserIdent, if set, is used as an additional component in the devp2p node identifier.
    UserIdent string `toml:",omitempty"`

    // Version should be set to the version number of the program. It is used
    // in the devp2p node identifier.
    Version string `toml:"-"`

    // 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

    // Configuration of peer-to-peer networking.
    P2P p2p.Config

    // KeyStoreDir is the file system folder that contains private keys. The directory can
    // be specified as a relative path, in which case it is resolved relative to the
    // current directory.
    //
    // If KeyStoreDir is empty, the default location is the "keystore" subdirectory of
    // DataDir. If DataDir is unspecified and KeyStoreDir is empty, an ephemeral directory
    // is created by New and destroyed when the node is stopped.
    KeyStoreDir string `toml:",omitempty"`

    // UseLightweightKDF lowers the memory and CPU requirements of the key store
    // scrypt KDF at the expense of security.
    UseLightweightKDF bool `toml:",omitempty"`

    // NoUSB disables hardware wallet monitoring and connectivity.
    NoUSB bool `toml:",omitempty"`

    // IPCPath is the requested location to place the IPC endpoint. If the path is
    // a simple file name, it is placed inside the data directory (or on the root
    // pipe path on Windows), whereas if it's a resolvable path name (absolute or
    // relative), then that specific path is enforced. An empty path disables IPC.
    IPCPath string `toml:",omitempty"`

    // HTTPHost is the host interface on which to start the HTTP RPC server. If this
    // field is empty, no HTTP API endpoint will be started.
    HTTPHost string `toml:",omitempty"`

    // HTTPPort is the TCP port number on which to start the HTTP RPC server. The
    // default zero value is/ valid and will pick a port number randomly (useful
    // for ephemeral nodes).
    HTTPPort int `toml:",omitempty"`

    // HTTPCors is the Cross-Origin Resource Sharing header to send to requesting
    // clients. Please be aware that CORS is a browser enforced security, it's fully
    // useless for custom HTTP clients.
    HTTPCors []string `toml:",omitempty"`

    // HTTPVirtualHosts is the list of virtual hostnames which are allowed on incoming requests.
    // This is by default {'localhost'}. Using this prevents attacks like
    // DNS rebinding, which bypasses SOP by simply masquerading as being within the same
    // origin. These attacks do not utilize CORS, since they are not cross-domain.
    // By explicitly checking the Host-header, the server will not allow requests
    // made against the server with a malicious host domain.
    // Requests using ip address directly are not affected
    HTTPVirtualHosts []string `toml:",omitempty"`

    // HTTPModules is a list of API modules to expose via the HTTP RPC interface.
    // If the module list is empty, all RPC API endpoints designated public will be
    // exposed.
    HTTPModules []string `toml:",omitempty"`

    // WSHost is the host interface on which to start the websocket RPC server. If
    // this field is empty, no websocket API endpoint will be started.
    WSHost string `toml:",omitempty"`

    // WSPort is the TCP port number on which to start the websocket RPC server. The
    // default zero value is/ valid and will pick a port number randomly (useful for
    // ephemeral nodes).
    WSPort int `toml:",omitempty"`

    // WSOrigins is the list of domain to accept websocket requests from. Please be
    // aware that the server can only act upon the HTTP request the client sends and
    // cannot verify the validity of the request header.
    WSOrigins []string `toml:",omitempty"`

    // WSModules is a list of API modules to expose via the websocket RPC interface.
    // If the module list is empty, all RPC API endpoints designated public will be
    // exposed.
    WSModules []string `toml:",omitempty"`

    // WSExposeAll exposes all API modules via the WebSocket RPC interface rather
    // than just the public ones.
    //
    // *WARNING* Only set this if the node is running in a trusted network, exposing
    // private APIs to untrusted users is a major security risk.
    WSExposeAll bool `toml:",omitempty"`

    // Logger is a custom logger to use with the p2p.Server.
    Logger log.Logger `toml:",omitempty"`
}

// IPCEndpoint resolves an IPC endpoint based on a configured value, taking into
// account the set data folders as well as the designated platform we're currently
// running on.
func (c *Config) IPCEndpoint() string {
    // Short circuit if IPC has not been enabled
    if c.IPCPath == "" {
        return ""
    }
    // On windows we can only use plain top-level pipes
    if runtime.GOOS == "windows" {
        if strings.HasPrefix(c.IPCPath, `\\.\pipe\`) {
            return c.IPCPath
        }
        return `\\.\pipe\` + c.IPCPath
    }
    // Resolve names into the data directory full paths otherwise
    if filepath.Base(c.IPCPath) == c.IPCPath {
        if c.DataDir == "" {
            return filepath.Join(os.TempDir(), c.IPCPath)
        }
        return filepath.Join(c.DataDir, c.IPCPath)
    }
    return c.IPCPath
}

// NodeDB returns the path to the discovery node database.
func (c *Config) NodeDB() string {
    if c.DataDir == "" {
        return "" // ephemeral
    }
    return c.ResolvePath(datadirNodeDatabase)
}

// DefaultIPCEndpoint returns the IPC path used by default.
func DefaultIPCEndpoint(clientIdentifier string) string {
    if clientIdentifier == "" {
        clientIdentifier = strings.TrimSuffix(filepath.Base(os.Args[0]), ".exe")
        if clientIdentifier == "" {
            panic("empty executable name")
        }
    }
    config := &Config{DataDir: DefaultDataDir(), IPCPath: clientIdentifier + ".ipc"}
    return config.IPCEndpoint()
}

// HTTPEndpoint resolves an HTTP endpoint based on the configured host interface
// and port parameters.
func (c *Config) HTTPEndpoint() string {
    if c.HTTPHost == "" {
        return ""
    }
    return fmt.Sprintf("%s:%d", c.HTTPHost, c.HTTPPort)
}

// DefaultHTTPEndpoint returns the HTTP endpoint used by default.
func DefaultHTTPEndpoint() string {
    config := &Config{HTTPHost: DefaultHTTPHost, HTTPPort: DefaultHTTPPort}
    return config.HTTPEndpoint()
}

// WSEndpoint resolves a websocket endpoint based on the configured host interface
// and port parameters.
func (c *Config) WSEndpoint() string {
    if c.WSHost == "" {
        return ""
    }
    return fmt.Sprintf("%s:%d", c.WSHost, c.WSPort)
}

// DefaultWSEndpoint returns the websocket endpoint used by default.
func DefaultWSEndpoint() string {
    config := &Config{WSHost: DefaultWSHost, WSPort: DefaultWSPort}
    return config.WSEndpoint()
}

// NodeName returns the devp2p node identifier.
func (c *Config) NodeName() string {
    name := c.name()
    // Backwards compatibility: previous versions used title-cased "Geth", keep that.
    if name == "geth" || name == "geth-testnet" {
        name = "Geth"
    }
    if c.UserIdent != "" {
        name += "/" + c.UserIdent
    }
    if c.Version != "" {
        name += "/v" + c.Version
    }
    name += "/" + runtime.GOOS + "-" + runtime.GOARCH
    name += "/" + runtime.Version()
    return name
}

func (c *Config) name() string {
    if c.Name == "" {
        progname := strings.TrimSuffix(filepath.Base(os.Args[0]), ".exe")
        if progname == "" {
            panic("empty executable name, set Config.Name")
        }
        return progname
    }
    return c.Name
}

// These resources are resolved differently for "geth" instances.
var isOldGethResource = map[string]bool{
    "chaindata":          true,
    "nodes":              true,
    "nodekey":            true,
    "static-nodes.json":  true,
    "trusted-nodes.json": true,
}

// ResolvePath resolves path in the instance directory.
func (c *Config) ResolvePath(path string) string {
    if filepath.IsAbs(path) {
        return path
    }
    if c.DataDir == "" {
        return ""
    }
    // Backwards-compatibility: ensure that data directory files created
    // by geth 1.4 are used if they exist.
    if c.name() == "geth" && isOldGethResource[path] {
        oldpath := ""
        if c.Name == "geth" {
            oldpath = filepath.Join(c.DataDir, path)
        }
        if oldpath != "" && common.FileExist(oldpath) {
            // TODO: print warning
            return oldpath
        }
    }
    return filepath.Join(c.instanceDir(), path)
}

func (c *Config) instanceDir() string {
    if c.DataDir == "" {
        return ""
    }
    return filepath.Join(c.DataDir, c.name())
}

// 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.P2P.PrivateKey != nil {
        return c.P2P.PrivateKey
    }
    // Generate ephemeral key if no datadir is being used.
    if c.DataDir == "" {
        key, err := crypto.GenerateKey()
        if err != nil {
            log.Crit(fmt.Sprintf("Failed to generate ephemeral node key: %v", err))
        }
        return key
    }

    keyfile := c.ResolvePath(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 {
        log.Crit(fmt.Sprintf("Failed to generate node key: %v", err))
    }
    instanceDir := filepath.Join(c.DataDir, c.name())
    if err := os.MkdirAll(instanceDir, 0700); err != nil {
        log.Error(fmt.Sprintf("Failed to persist node key: %v", err))
        return key
    }
    keyfile = filepath.Join(instanceDir, datadirPrivateKey)
    if err := crypto.SaveECDSA(keyfile, key); err != nil {
        log.Error(fmt.Sprintf("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(c.ResolvePath(datadirStaticNodes))
}

// TrustedNodes returns a list of node enode URLs configured as trusted nodes.
func (c *Config) TrustedNodes() []*discover.Node {
    return c.parsePersistentNodes(c.ResolvePath(datadirTrustedNodes))
}

// parsePersistentNodes parses a list of discovery node URLs loaded from a .json
// file from within the data directory.
func (c *Config) parsePersistentNodes(path string) []*discover.Node {
    // Short circuit if no node config is present
    if c.DataDir == "" {
        return nil
    }
    if _, err := os.Stat(path); err != nil {
        return nil
    }
    // Load the nodes from the config file.
    var nodelist []string
    if err := common.LoadJSON(path, &nodelist); err != nil {
        log.Error(fmt.Sprintf("Can't load node file %s: %v", path, 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 {
            log.Error(fmt.Sprintf("Node URL %s: %v\n", url, err))
            continue
        }
        nodes = append(nodes, node)
    }
    return nodes
}

// AccountConfig determines the settings for scrypt and keydirectory
func (c *Config) AccountConfig() (int, int, string, error) {
    scryptN := keystore.StandardScryptN
    scryptP := keystore.StandardScryptP
    if c.UseLightweightKDF {
        scryptN = keystore.LightScryptN
        scryptP = keystore.LightScryptP
    }

    var (
        keydir string
        err    error
    )
    switch {
    case filepath.IsAbs(c.KeyStoreDir):
        keydir = c.KeyStoreDir
    case c.DataDir != "":
        if c.KeyStoreDir == "" {
            keydir = filepath.Join(c.DataDir, datadirDefaultKeyStore)
        } else {
            keydir, err = filepath.Abs(c.KeyStoreDir)
        }
    case c.KeyStoreDir != "":
        keydir, err = filepath.Abs(c.KeyStoreDir)
    }
    return scryptN, scryptP, keydir, err
}

func makeAccountManager(conf *Config) (*accounts.Manager, string, error) {
    scryptN, scryptP, keydir, err := conf.AccountConfig()
    var ephemeral string
    if keydir == "" {
        // There is no datadir.
        keydir, err = ioutil.TempDir("", "go-ethereum-keystore")
        ephemeral = keydir
    }

    if err != nil {
        return nil, "", err
    }
    if err := os.MkdirAll(keydir, 0700); err != nil {
        return nil, "", err
    }
    // Assemble the account manager and supported backends
    backends := []accounts.Backend{
        keystore.NewKeyStore(keydir, scryptN, scryptP),
    }
    if !conf.NoUSB {
        // Start a USB hub for Ledger hardware wallets
        if ledgerhub, err := usbwallet.NewLedgerHub(); err != nil {
            log.Warn(fmt.Sprintf("Failed to start Ledger hub, disabling: %v", err))
        } else {
            backends = append(backends, ledgerhub)
        }
        // Start a USB hub for Trezor hardware wallets
        if trezorhub, err := usbwallet.NewTrezorHub(); err != nil {
            log.Warn(fmt.Sprintf("Failed to start Trezor hub, disabling: %v", err))
        } else {
            backends = append(backends, trezorhub)
        }
    }
    return accounts.NewManager(backends...), ephemeral, nil
}