path: root/node/node.go

// 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 <http://www.gnu.org/licenses/>.

package node

import (
    "errors"
    "fmt"
    "net"
    "os"
    "path/filepath"
    "reflect"
    "strings"
    "sync"
    "syscall"

    "github.com/ethereum/go-ethereum/accounts"
    "github.com/ethereum/go-ethereum/ethdb"
    "github.com/ethereum/go-ethereum/event"
    "github.com/ethereum/go-ethereum/internal/debug"
    "github.com/ethereum/go-ethereum/log"
    "github.com/ethereum/go-ethereum/p2p"
    "github.com/ethereum/go-ethereum/rpc"
    "github.com/syndtr/goleveldb/leveldb/storage"
)

var (
    ErrDatadirUsed    = errors.New("datadir already used")
    ErrNodeStopped    = errors.New("node not started")
    ErrNodeRunning    = errors.New("node already running")
    ErrServiceUnknown = errors.New("unknown service")

    datadirInUseErrnos = map[uint]bool{11: true, 32: true, 35: true}
)

// Node is a container on which services can be registered.
type Node struct {
    eventmux *event.TypeMux // Event multiplexer used between the services of a stack
    config   *Config
    accman   *accounts.Manager

    ephemeralKeystore string          // if non-empty, the key directory that will be removed by Stop
    instanceDirLock   storage.Storage // prevents concurrent use of instance directory

    serverConfig p2p.Config
    server       *p2p.Server // Currently running P2P networking layer

    serviceFuncs []ServiceConstructor     // Service constructors (in dependency order)
    services     map[reflect.Type]Service // Currently running services

    rpcAPIs       []rpc.API   // List of APIs currently provided by the node
    inprocHandler *rpc.Server // In-process RPC request handler to process the API requests

    ipcEndpoint string       // IPC endpoint to listen at (empty = IPC disabled)
    ipcListener net.Listener // IPC RPC listener socket to serve API requests
    ipcHandler  *rpc.Server  // IPC RPC request handler to process the API requests

    httpEndpoint  string       // HTTP endpoint (interface + port) to listen at (empty = HTTP disabled)
    httpWhitelist []string     // HTTP RPC modules to allow through this endpoint
    httpListener  net.Listener // HTTP RPC listener socket to server API requests
    httpHandler   *rpc.Server  // HTTP RPC request handler to process the API requests

    wsEndpoint string       // Websocket endpoint (interface + port) to listen at (empty = websocket disabled)
    wsListener net.Listener // Websocket RPC listener socket to server API requests
    wsHandler  *rpc.Server  // Websocket RPC request handler to process the API requests

    stop chan struct{} // Channel to wait for termination notifications
    lock sync.RWMutex
}

// New creates a new P2P node, ready for protocol registration.
func New(conf *Config) (*Node, error) {
    // Copy config and resolve the datadir so future changes to the current
    // working directory don't affect the node.
    confCopy := *conf
    conf = &confCopy
    if conf.DataDir != "" {
        absdatadir, err := filepath.Abs(conf.DataDir)
        if err != nil {
            return nil, err
        }
        conf.DataDir = absdatadir
    }
    // Ensure that the instance name doesn't cause weird conflicts with
    // other files in the data directory.
    if strings.ContainsAny(conf.Name, `/\`) {
        return nil, errors.New(`Config.Name must not contain '/' or '\'`)
    }
    if conf.Name == datadirDefaultKeyStore {
        return nil, errors.New(`Config.Name cannot be "` + datadirDefaultKeyStore + `"`)
    }
    if strings.HasSuffix(conf.Name, ".ipc") {
        return nil, errors.New(`Config.Name cannot end in ".ipc"`)
    }
    // Ensure that the AccountManager method works before the node has started.
    // We rely on this in cmd/geth.
    am, ephemeralKeystore, err := makeAccountManager(conf)
    if err != nil {
        return nil, err
    }
    // Note: any interaction with Config that would create/touch files
    // in the data directory or instance directory is delayed until Start.
    return &Node{
        accman:            am,
        ephemeralKeystore: ephemeralKeystore,
        config:            conf,
        serviceFuncs:      []ServiceConstructor{},
        ipcEndpoint:       conf.IPCEndpoint(),
        httpEndpoint:      conf.HTTPEndpoint(),
        wsEndpoint:        conf.WSEndpoint(),
        eventmux:          new(event.TypeMux),
    }, nil
}

// Register injects a new service into the node's stack. The service created by
// the passed constructor must be unique in its type with regard to sibling ones.
func (n *Node) Register(constructor ServiceConstructor) error {
    n.lock.Lock()
    defer n.lock.Unlock()

    if n.server != nil {
        return ErrNodeRunning
    }
    n.serviceFuncs = append(n.serviceFuncs, constructor)
    return nil
}

// Start create a live P2P node and starts running it.
func (n *Node) Start() error {
    n.lock.Lock()
    defer n.lock.Unlock()

    // Short circuit if the node's already running
    if n.server != nil {
        return ErrNodeRunning
    }
    if err := n.openDataDir(); err != nil {
        return err
    }

    // Initialize the p2p server. This creates the node key and
    // discovery databases.
    n.serverConfig = n.config.P2P
    n.serverConfig.PrivateKey = n.config.NodeKey()
    n.serverConfig.Name = n.config.NodeName()
    if n.serverConfig.StaticNodes == nil {
        n.serverConfig.StaticNodes = n.config.StaticNodes()
    }
    if n.serverConfig.TrustedNodes == nil {
        n.serverConfig.TrustedNodes = n.config.TrusterNodes()
    }
    if n.serverConfig.NodeDatabase == "" {
        n.serverConfig.NodeDatabase = n.config.NodeDB()
    }
    running := &p2p.Server{Config: n.serverConfig}
    log.Info("Starting peer-to-peer node", "instance", n.serverConfig.Name)

    // Otherwise copy and specialize the P2P configuration
    services := make(map[reflect.Type]Service)
    for _, constructor := range n.serviceFuncs {
        // Create a new context for the particular service
        ctx := &ServiceContext{
            config:         n.config,
            services:       make(map[reflect.Type]Service),
            EventMux:       n.eventmux,
            AccountManager: n.accman,
        }
        for kind, s := range services { // copy needed for threaded access
            ctx.services[kind] = s
        }
        // Construct and save the service
        service, err := constructor(ctx)
        if err != nil {
            return err
        }
        kind := reflect.TypeOf(service)
        if _, exists := services[kind]; exists {
            return &DuplicateServiceError{Kind: kind}
        }
        services[kind] = service
    }
    // Gather the protocols and start the freshly assembled P2P server
    for _, service := range services {
        running.Protocols = append(running.Protocols, service.Protocols()...)
    }
    if err := running.Start(); err != nil {
        if errno, ok := err.(syscall.Errno); ok && datadirInUseErrnos[uint(errno)] {
            return ErrDatadirUsed
        }
        return err
    }
    // Start each of the services
    started := []reflect.Type{}
    for kind, service := range services {
        // Start the next service, stopping all previous upon failure
        if err := service.Start(running); err != nil {
            for _, kind := range started {
                services[kind].Stop()
            }
            running.Stop()

            return err
        }
        // Mark the service started for potential cleanup
        started = append(started, kind)
    }
    // Lastly start the configured RPC interfaces
    if err := n.startRPC(services); err != nil {
        for _, service := range services {
            service.Stop()
        }
        running.Stop()
        return err
    }
    // Finish initializing the startup
    n.services = services
    n.server = running
    n.stop = make(chan struct{})

    return nil
}

func (n *Node) openDataDir() error {
    if n.config.DataDir == "" {
        return nil // ephemeral
    }

    instdir := filepath.Join(n.config.DataDir, n.config.name())
    if err := os.MkdirAll(instdir, 0700); err != nil {
        return err
    }
    // Try to open the instance directory as LevelDB storage. This creates a lock file
    // which prevents concurrent use by another instance as well as accidental use of the
    // instance directory as a database.
    storage, err := storage.OpenFile(instdir, true)
    if err != nil {
        return err
    }
    n.instanceDirLock = storage
    return nil
}

// startRPC is a helper method to start all the various RPC endpoint during node
// startup. It's not meant to be called at any time afterwards as it makes certain
// assumptions about the state of the node.
func (n *Node) startRPC(services map[reflect.Type]Service) error {
    // Gather all the possible APIs to surface
    apis := n.apis()
    for _, service := range services {
        apis = append(apis, service.APIs()...)
    }
    // Start the various API endpoints, terminating all in case of errors
    if err := n.startInProc(apis); err != nil {
        return err
    }
    if err := n.startIPC(apis); err != nil {
        n.stopInProc()
        return err
    }
    if err := n.startHTTP(n.httpEndpoint, apis, n.config.HTTPModules, n.config.HTTPCors); err != nil {
        n.stopIPC()
        n.stopInProc()
        return err
    }
    if err := n.startWS(n.wsEndpoint, apis, n.config.WSModules, n.config.WSOrigins); err != nil {
        n.stopHTTP()
        n.stopIPC()
        n.stopInProc()
        return err
    }
    // All API endpoints started successfully
    n.rpcAPIs = apis
    return nil
}

// startInProc initializes an in-process RPC endpoint.
func (n *Node) startInProc(apis []rpc.API) error {
    // Register all the APIs exposed by the services
    handler := rpc.NewServer()
    for _, api := range apis {
        if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
            return err
        }
        log.Debug(fmt.Sprintf("InProc registered %T under '%s'", api.Service, api.Namespace))
    }
    n.inprocHandler = handler
    return nil
}

// stopInProc terminates the in-process RPC endpoint.
func (n *Node) stopInProc() {
    if n.inprocHandler != nil {
        n.inprocHandler.Stop()
        n.inprocHandler = nil
    }
}

// startIPC initializes and starts the IPC RPC endpoint.
func (n *Node) startIPC(apis []rpc.API) error {
    // Short circuit if the IPC endpoint isn't being exposed
    if n.ipcEndpoint == "" {
        return nil
    }
    // Register all the APIs exposed by the services
    handler := rpc.NewServer()
    for _, api := range apis {
        if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
            return err
        }
        log.Debug(fmt.Sprintf("IPC registered %T under '%s'", api.Service, api.Namespace))
    }
    // All APIs registered, start the IPC listener
    var (
        listener net.Listener
        err      error
    )
    if listener, err = rpc.CreateIPCListener(n.ipcEndpoint); err != nil {
        return err
    }
    go func() {
        log.Info(fmt.Sprintf("IPC endpoint opened: %s", n.ipcEndpoint))

        for {
            conn, err := listener.Accept()
            if err != nil {
                // Terminate if the listener was closed
                n.lock.RLock()
                closed := n.ipcListener == nil
                n.lock.RUnlock()
                if closed {
                    return
                }
                // Not closed, just some error; report and continue
                log.Error(fmt.Sprintf("IPC accept failed: %v", err))
                continue
            }
            go handler.ServeCodec(rpc.NewJSONCodec(conn), rpc.OptionMethodInvocation|rpc.OptionSubscriptions)
        }
    }()
    // All listeners booted successfully
    n.ipcListener = listener
    n.ipcHandler = handler

    return nil
}

// stopIPC terminates the IPC RPC endpoint.
func (n *Node) stopIPC() {
    if n.ipcListener != nil {
        n.ipcListener.Close()
        n.ipcListener = nil

        log.Info(fmt.Sprintf("IPC endpoint closed: %s", n.ipcEndpoint))
    }
    if n.ipcHandler != nil {
        n.ipcHandler.Stop()
        n.ipcHandler = nil
    }
}

// startHTTP initializes and starts the HTTP RPC endpoint.
func (n *Node) startHTTP(endpoint string, apis []rpc.API, modules []string, cors []string) error {
    // Short circuit if the HTTP endpoint isn't being exposed
    if endpoint == "" {
        return nil
    }
    // Generate the whitelist based on the allowed modules
    whitelist := make(map[string]bool)
    for _, module := range modules {
        whitelist[module] = true
    }
    // Register all the APIs exposed by the services
    handler := rpc.NewServer()
    for _, api := range apis {
        if whitelist[api.Namespace] || (len(whitelist) == 0 && api.Public) {
            if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
                return err
            }
            log.Debug(fmt.Sprintf("HTTP registered %T under '%s'", api.Service, api.Namespace))
        }
    }
    // All APIs registered, start the HTTP listener
    var (
        listener net.Listener
        err      error
    )
    if listener, err = net.Listen("tcp", endpoint); err != nil {
        return err
    }
    go rpc.NewHTTPServer(cors, handler).Serve(listener)
    log.Info(fmt.Sprintf("HTTP endpoint opened: http://%s", endpoint))

    // All listeners booted successfully
    n.httpEndpoint = endpoint
    n.httpListener = listener
    n.httpHandler = handler

    return nil
}

// stopHTTP terminates the HTTP RPC endpoint.
func (n *Node) stopHTTP() {
    if n.httpListener != nil {
        n.httpListener.Close()
        n.httpListener = nil

        log.Info(fmt.Sprintf("HTTP endpoint closed: http://%s", n.httpEndpoint))
    }
    if n.httpHandler != nil {
        n.httpHandler.Stop()
        n.httpHandler = nil
    }
}

// startWS initializes and starts the websocket RPC endpoint.
func (n *Node) startWS(endpoint string, apis []rpc.API, modules []string, wsOrigins []string) error {
    // Short circuit if the WS endpoint isn't being exposed
    if endpoint == "" {
        return nil
    }
    // Generate the whitelist based on the allowed modules
    whitelist := make(map[string]bool)
    for _, module := range modules {
        whitelist[module] = true
    }
    // Register all the APIs exposed by the services
    handler := rpc.NewServer()
    for _, api := range apis {
        if whitelist[api.Namespace] || (len(whitelist) == 0 && api.Public) {
            if err := handler.RegisterName(api.Namespace, api.Service); err != nil {
                return err
            }
            log.Debug(fmt.Sprintf("WebSocket registered %T under '%s'", api.Service, api.Namespace))
        }
    }
    // All APIs registered, start the HTTP listener
    var (
        listener net.Listener
        err      error
    )
    if listener, err = net.Listen("tcp", endpoint); err != nil {
        return err
    }
    go rpc.NewWSServer(wsOrigins, handler).Serve(listener)
    log.Info(fmt.Sprintf("WebSocket endpoint opened: ws://%s", endpoint))

    // All listeners booted successfully
    n.wsEndpoint = endpoint
    n.wsListener = listener
    n.wsHandler = handler

    return nil
}

// stopWS terminates the websocket RPC endpoint.
func (n *Node) stopWS() {
    if n.wsListener != nil {
        n.wsListener.Close()
        n.wsListener = nil

        log.Info(fmt.Sprintf("WebSocket endpoint closed: ws://%s", n.wsEndpoint))
    }
    if n.wsHandler != nil {
        n.wsHandler.Stop()
        n.wsHandler = nil
    }
}

// Stop terminates a running node along with all it's services. In the node was
// not started, an error is returned.
func (n *Node) Stop() error {
    n.lock.Lock()
    defer n.lock.Unlock()

    // Short circuit if the node's not running
    if n.server == nil {
        return ErrNodeStopped
    }

    // Terminate the API, services and the p2p server.
    n.stopWS()
    n.stopHTTP()
    n.stopIPC()
    n.rpcAPIs = nil
    failure := &StopError{
        Services: make(map[reflect.Type]error),
    }
    for kind, service := range n.services {
        if err := service.Stop(); err != nil {
            failure.Services[kind] = err
        }
    }
    n.server.Stop()
    n.services = nil
    n.server = nil

    // Release instance directory lock.
    if n.instanceDirLock != nil {
        n.instanceDirLock.Close()
        n.instanceDirLock = nil
    }

    // unblock n.Wait
    close(n.stop)

    // Remove the keystore if it was created ephemerally.
    var keystoreErr error
    if n.ephemeralKeystore != "" {
        keystoreErr = os.RemoveAll(n.ephemeralKeystore)
    }

    if len(failure.Services) > 0 {
        return failure
    }
    if keystoreErr != nil {
        return keystoreErr
    }
    return nil
}

// Wait blocks the thread until the node is stopped. If the node is not running
// at the time of invocation, the method immediately returns.
func (n *Node) Wait() {
    n.lock.RLock()
    if n.server == nil {
        n.lock.RUnlock()
        return
    }
    stop := n.stop
    n.lock.RUnlock()

    <-stop
}

// Restart terminates a running node and boots up a new one in its place. If the
// node isn't running, an error is returned.
func (n *Node) Restart() error {
    if err := n.Stop(); err != nil {
        return err
    }
    if err := n.Start(); err != nil {
        return err
    }
    return nil
}

// Attach creates an RPC client attached to an in-process API handler.
func (n *Node) Attach() (*rpc.Client, error) {
    n.lock.RLock()
    defer n.lock.RUnlock()

    if n.server == nil {
        return nil, ErrNodeStopped
    }
    return rpc.DialInProc(n.inprocHandler), nil
}

// Server retrieves the currently running P2P network layer. This method is meant
// only to inspect fields of the currently running server, life cycle management
// should be left to this Node entity.
func (n *Node) Server() *p2p.Server {
    n.lock.RLock()
    defer n.lock.RUnlock()

    return n.server
}

// Service retrieves a currently running service registered of a specific type.
func (n *Node) Service(service interface{}) error {
    n.lock.RLock()
    defer n.lock.RUnlock()

    // Short circuit if the node's not running
    if n.server == nil {
        return ErrNodeStopped
    }
    // Otherwise try to find the service to return
    element := reflect.ValueOf(service).Elem()
    if running, ok := n.services[element.Type()]; ok {
        element.Set(reflect.ValueOf(running))
        return nil
    }
    return ErrServiceUnknown
}

// DataDir retrieves the current datadir used by the protocol stack.
// Deprecated: No files should be stored in this directory, use InstanceDir instead.
func (n *Node) DataDir() string {
    return n.config.DataDir
}

// InstanceDir retrieves the instance directory used by the protocol stack.
func (n *Node) InstanceDir() string {
    return n.config.instanceDir()
}

// AccountManager retrieves the account manager used by the protocol stack.
func (n *Node) AccountManager() *accounts.Manager {
    return n.accman
}

// IPCEndpoint retrieves the current IPC endpoint used by the protocol stack.
func (n *Node) IPCEndpoint() string {
    return n.ipcEndpoint
}

// HTTPEndpoint retrieves the current HTTP endpoint used by the protocol stack.
func (n *Node) HTTPEndpoint() string {
    return n.httpEndpoint
}

// WSEndpoint retrieves the current WS endpoint used by the protocol stack.
func (n *Node) WSEndpoint() string {
    return n.wsEndpoint
}

// EventMux retrieves the event multiplexer used by all the network services in
// the current protocol stack.
func (n *Node) EventMux() *event.TypeMux {
    return n.eventmux
}

// OpenDatabase opens an existing database with the given name (or creates one if no
// previous can be found) from within the node's instance directory. If the node is
// ephemeral, a memory database is returned.
func (n *Node) OpenDatabase(name string, cache, handles int) (ethdb.Database, error) {
    if n.config.DataDir == "" {
        return ethdb.NewMemDatabase()
    }
    return ethdb.NewLDBDatabase(n.config.resolvePath(name), cache, handles)
}

// ResolvePath returns the absolute path of a resource in the instance directory.
func (n *Node) ResolvePath(x string) string {
    return n.config.resolvePath(x)
}

// apis returns the collection of RPC descriptors this node offers.
func (n *Node) apis() []rpc.API {
    return []rpc.API{
        {
            Namespace: "admin",
            Version:   "1.0",
            Service:   NewPrivateAdminAPI(n),
        }, {
            Namespace: "admin",
            Version:   "1.0",
            Service:   NewPublicAdminAPI(n),
            Public:    true,
        }, {
            Namespace: "debug",
            Version:   "1.0",
            Service:   debug.Handler,
        }, {
            Namespace: "debug",
            Version:   "1.0",
            Service:   NewPublicDebugAPI(n),
            Public:    true,
        }, {
            Namespace: "web3",
            Version:   "1.0",
            Service:   NewPublicWeb3API(n),
            Public:    true,
        },
    }
}