path: root/swarm/swarm.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 swarm

import (
    "bytes"
    "context"
    "crypto/ecdsa"
    "fmt"
    "io"
    "math/big"
    "net"
    "path/filepath"
    "strings"
    "time"
    "unicode"

    "github.com/ethereum/go-ethereum/accounts/abi/bind"
    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/contracts/chequebook"
    "github.com/ethereum/go-ethereum/contracts/ens"
    "github.com/ethereum/go-ethereum/ethclient"
    "github.com/ethereum/go-ethereum/metrics"
    "github.com/ethereum/go-ethereum/p2p"
    "github.com/ethereum/go-ethereum/p2p/enode"
    "github.com/ethereum/go-ethereum/p2p/protocols"
    "github.com/ethereum/go-ethereum/params"
    "github.com/ethereum/go-ethereum/rpc"
    "github.com/ethereum/go-ethereum/swarm/api"
    httpapi "github.com/ethereum/go-ethereum/swarm/api/http"
    "github.com/ethereum/go-ethereum/swarm/fuse"
    "github.com/ethereum/go-ethereum/swarm/log"
    "github.com/ethereum/go-ethereum/swarm/network"
    "github.com/ethereum/go-ethereum/swarm/network/stream"
    "github.com/ethereum/go-ethereum/swarm/pss"
    "github.com/ethereum/go-ethereum/swarm/state"
    "github.com/ethereum/go-ethereum/swarm/storage"
    "github.com/ethereum/go-ethereum/swarm/storage/feed"
    "github.com/ethereum/go-ethereum/swarm/storage/mock"
    "github.com/ethereum/go-ethereum/swarm/swap"
    "github.com/ethereum/go-ethereum/swarm/tracing"
)

var (
    startTime          time.Time
    updateGaugesPeriod = 5 * time.Second
    startCounter       = metrics.NewRegisteredCounter("stack,start", nil)
    stopCounter        = metrics.NewRegisteredCounter("stack,stop", nil)
    uptimeGauge        = metrics.NewRegisteredGauge("stack.uptime", nil)
    requestsCacheGauge = metrics.NewRegisteredGauge("storage.cache.requests.size", nil)
)

// the swarm stack
type Swarm struct {
    config            *api.Config        // swarm configuration
    api               *api.API           // high level api layer (fs/manifest)
    dns               api.Resolver       // DNS registrar
    fileStore         *storage.FileStore // distributed preimage archive, the local API to the storage with document level storage/retrieval support
    streamer          *stream.Registry
    bzz               *network.Bzz       // the logistic manager
    backend           chequebook.Backend // simple blockchain Backend
    privateKey        *ecdsa.PrivateKey
    corsString        string
    swapEnabled       bool
    netStore          *storage.NetStore
    sfs               *fuse.SwarmFS // need this to cleanup all the active mounts on node exit
    ps                *pss.Pss
    swap              *swap.Swap
    stateStore        *state.DBStore
    accountingMetrics *protocols.AccountingMetrics

    tracerClose io.Closer
}

type SwarmAPI struct {
    Api     *api.API
    Backend chequebook.Backend
}

func (self *Swarm) API() *SwarmAPI {
    return &SwarmAPI{
        Api:     self.api,
        Backend: self.backend,
    }
}

// creates a new swarm service instance
// implements node.Service
// If mockStore is not nil, it will be used as the storage for chunk data.
// MockStore should be used only for testing.
func NewSwarm(config *api.Config, mockStore *mock.NodeStore) (self *Swarm, err error) {

    if bytes.Equal(common.FromHex(config.PublicKey), storage.ZeroAddr) {
        return nil, fmt.Errorf("empty public key")
    }
    if bytes.Equal(common.FromHex(config.BzzKey), storage.ZeroAddr) {
        return nil, fmt.Errorf("empty bzz key")
    }

    var backend chequebook.Backend
    if config.SwapAPI != "" && config.SwapEnabled {
        log.Info("connecting to SWAP API", "url", config.SwapAPI)
        backend, err = ethclient.Dial(config.SwapAPI)
        if err != nil {
            return nil, fmt.Errorf("error connecting to SWAP API %s: %s", config.SwapAPI, err)
        }
    }

    self = &Swarm{
        config:     config,
        backend:    backend,
        privateKey: config.ShiftPrivateKey(),
    }
    log.Debug("Setting up Swarm service components")

    config.HiveParams.Discovery = true

    bzzconfig := &network.BzzConfig{
        NetworkID:   config.NetworkID,
        OverlayAddr: common.FromHex(config.BzzKey),
        HiveParams:  config.HiveParams,
        LightNode:   config.LightNodeEnabled,
    }

    self.stateStore, err = state.NewDBStore(filepath.Join(config.Path, "state-store.db"))
    if err != nil {
        return
    }

    // set up high level api
    var resolver *api.MultiResolver
    if len(config.EnsAPIs) > 0 {
        opts := []api.MultiResolverOption{}
        for _, c := range config.EnsAPIs {
            tld, endpoint, addr := parseEnsAPIAddress(c)
            r, err := newEnsClient(endpoint, addr, config, self.privateKey)
            if err != nil {
                return nil, err
            }
            opts = append(opts, api.MultiResolverOptionWithResolver(r, tld))

        }
        resolver = api.NewMultiResolver(opts...)
        self.dns = resolver
    }

    lstore, err := storage.NewLocalStore(config.LocalStoreParams, mockStore)
    if err != nil {
        return nil, err
    }

    self.netStore, err = storage.NewNetStore(lstore, nil)
    if err != nil {
        return nil, err
    }

    to := network.NewKademlia(
        common.FromHex(config.BzzKey),
        network.NewKadParams(),
    )
    delivery := stream.NewDelivery(to, self.netStore)
    self.netStore.NewNetFetcherFunc = network.NewFetcherFactory(delivery.RequestFromPeers, config.DeliverySkipCheck).New

    if config.SwapEnabled {
        balancesStore, err := state.NewDBStore(filepath.Join(config.Path, "balances.db"))
        if err != nil {
            return nil, err
        }
        self.swap = swap.New(balancesStore)
        self.accountingMetrics = protocols.SetupAccountingMetrics(10*time.Second, filepath.Join(config.Path, "metrics.db"))
    }

    var nodeID enode.ID
    if err := nodeID.UnmarshalText([]byte(config.NodeID)); err != nil {
        return nil, err
    }

    syncing := stream.SyncingAutoSubscribe
    if !config.SyncEnabled || config.LightNodeEnabled {
        syncing = stream.SyncingDisabled
    }

    retrieval := stream.RetrievalEnabled
    if config.LightNodeEnabled {
        retrieval = stream.RetrievalClientOnly
    }

    registryOptions := &stream.RegistryOptions{
        SkipCheck:       config.DeliverySkipCheck,
        Syncing:         syncing,
        Retrieval:       retrieval,
        SyncUpdateDelay: config.SyncUpdateDelay,
        MaxPeerServers:  config.MaxStreamPeerServers,
    }
    self.streamer = stream.NewRegistry(nodeID, delivery, self.netStore, self.stateStore, registryOptions, self.swap)

    // Swarm Hash Merklised Chunking for Arbitrary-length Document/File storage
    self.fileStore = storage.NewFileStore(self.netStore, self.config.FileStoreParams)

    var feedsHandler *feed.Handler
    fhParams := &feed.HandlerParams{}

    feedsHandler = feed.NewHandler(fhParams)
    feedsHandler.SetStore(self.netStore)

    lstore.Validators = []storage.ChunkValidator{
        storage.NewContentAddressValidator(storage.MakeHashFunc(storage.DefaultHash)),
        feedsHandler,
    }

    err = lstore.Migrate()
    if err != nil {
        return nil, err
    }

    log.Debug("Setup local storage")

    self.bzz = network.NewBzz(bzzconfig, to, self.stateStore, self.streamer.GetSpec(), self.streamer.Run)

    // Pss = postal service over swarm (devp2p over bzz)
    self.ps, err = pss.NewPss(to, config.Pss)
    if err != nil {
        return nil, err
    }
    if pss.IsActiveHandshake {
        pss.SetHandshakeController(self.ps, pss.NewHandshakeParams())
    }

    self.api = api.NewAPI(self.fileStore, self.dns, feedsHandler, self.privateKey)

    self.sfs = fuse.NewSwarmFS(self.api)
    log.Debug("Initialized FUSE filesystem")

    return self, nil
}

// parseEnsAPIAddress parses string according to format
// [tld:][contract-addr@]url and returns ENSClientConfig structure
// with endpoint, contract address and TLD.
func parseEnsAPIAddress(s string) (tld, endpoint string, addr common.Address) {
    isAllLetterString := func(s string) bool {
        for _, r := range s {
            if !unicode.IsLetter(r) {
                return false
            }
        }
        return true
    }
    endpoint = s
    if i := strings.Index(endpoint, ":"); i > 0 {
        if isAllLetterString(endpoint[:i]) && len(endpoint) > i+2 && endpoint[i+1:i+3] != "//" {
            tld = endpoint[:i]
            endpoint = endpoint[i+1:]
        }
    }
    if i := strings.Index(endpoint, "@"); i > 0 {
        addr = common.HexToAddress(endpoint[:i])
        endpoint = endpoint[i+1:]
    }
    return
}

// ensClient provides functionality for api.ResolveValidator
type ensClient struct {
    *ens.ENS
    *ethclient.Client
}

// newEnsClient creates a new ENS client for that is a consumer of
// a ENS API on a specific endpoint. It is used as a helper function
// for creating multiple resolvers in NewSwarm function.
func newEnsClient(endpoint string, addr common.Address, config *api.Config, privkey *ecdsa.PrivateKey) (*ensClient, error) {
    log.Info("connecting to ENS API", "url", endpoint)
    client, err := rpc.Dial(endpoint)
    if err != nil {
        return nil, fmt.Errorf("error connecting to ENS API %s: %s", endpoint, err)
    }
    ethClient := ethclient.NewClient(client)

    ensRoot := config.EnsRoot
    if addr != (common.Address{}) {
        ensRoot = addr
    } else {
        a, err := detectEnsAddr(client)
        if err == nil {
            ensRoot = a
        } else {
            log.Warn(fmt.Sprintf("could not determine ENS contract address, using default %s", ensRoot), "err", err)
        }
    }
    transactOpts := bind.NewKeyedTransactor(privkey)
    dns, err := ens.NewENS(transactOpts, ensRoot, ethClient)
    if err != nil {
        return nil, err
    }
    log.Debug(fmt.Sprintf("-> Swarm Domain Name Registrar %v @ address %v", endpoint, ensRoot.Hex()))
    return &ensClient{
        ENS:    dns,
        Client: ethClient,
    }, err
}

// detectEnsAddr determines the ENS contract address by getting both the
// version and genesis hash using the client and matching them to either
// mainnet or testnet addresses
func detectEnsAddr(client *rpc.Client) (common.Address, error) {
    ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
    defer cancel()

    var version string
    if err := client.CallContext(ctx, &version, "net_version"); err != nil {
        return common.Address{}, err
    }

    block, err := ethclient.NewClient(client).BlockByNumber(ctx, big.NewInt(0))
    if err != nil {
        return common.Address{}, err
    }

    switch {

    case version == "1" && block.Hash() == params.MainnetGenesisHash:
        log.Info("using Mainnet ENS contract address", "addr", ens.MainNetAddress)
        return ens.MainNetAddress, nil

    case version == "3" && block.Hash() == params.TestnetGenesisHash:
        log.Info("using Testnet ENS contract address", "addr", ens.TestNetAddress)
        return ens.TestNetAddress, nil

    default:
        return common.Address{}, fmt.Errorf("unknown version and genesis hash: %s %s", version, block.Hash())
    }
}

/*
Start is called when the stack is started
* starts the network kademlia hive peer management
* (starts netStore level 0 api)
* starts DPA level 1 api (chunking -> store/retrieve requests)
* (starts level 2 api)
* starts http proxy server
* registers url scheme handlers for bzz, etc
* TODO: start subservices like sword, swear, swarmdns
*/
// implements the node.Service interface
func (self *Swarm) Start(srv *p2p.Server) error {
    startTime = time.Now()

    self.tracerClose = tracing.Closer

    // update uaddr to correct enode
    newaddr := self.bzz.UpdateLocalAddr([]byte(srv.Self().String()))
    log.Info("Updated bzz local addr", "oaddr", fmt.Sprintf("%x", newaddr.OAddr), "uaddr", fmt.Sprintf("%s", newaddr.UAddr))
    // set chequebook
    //TODO: Currently if swap is enabled and no chequebook (or inexistent) contract is provided, the node would crash.
    //Once we integrate back the contracts, this check MUST be revisited
    if self.config.SwapEnabled && self.config.SwapAPI != "" {
        ctx := context.Background() // The initial setup has no deadline.
        err := self.SetChequebook(ctx)
        if err != nil {
            return fmt.Errorf("Unable to set chequebook for SWAP: %v", err)
        }
        log.Debug(fmt.Sprintf("-> cheque book for SWAP: %v", self.config.Swap.Chequebook()))
    } else {
        log.Debug(fmt.Sprintf("SWAP disabled: no cheque book set"))
    }

    log.Info("Starting bzz service")

    err := self.bzz.Start(srv)
    if err != nil {
        log.Error("bzz failed", "err", err)
        return err
    }
    log.Info("Swarm network started", "bzzaddr", fmt.Sprintf("%x", self.bzz.Hive.BaseAddr()))

    if self.ps != nil {
        self.ps.Start(srv)
    }

    // start swarm http proxy server
    if self.config.Port != "" {
        addr := net.JoinHostPort(self.config.ListenAddr, self.config.Port)
        server := httpapi.NewServer(self.api, self.config.Cors)

        if self.config.Cors != "" {
            log.Debug("Swarm HTTP proxy CORS headers", "allowedOrigins", self.config.Cors)
        }

        log.Debug("Starting Swarm HTTP proxy", "port", self.config.Port)
        go func() {
            err := server.ListenAndServe(addr)
            if err != nil {
                log.Error("Could not start Swarm HTTP proxy", "err", err.Error())
            }
        }()
    }

    self.periodicallyUpdateGauges()

    startCounter.Inc(1)
    self.streamer.Start(srv)
    return nil
}

func (self *Swarm) periodicallyUpdateGauges() {
    ticker := time.NewTicker(updateGaugesPeriod)

    go func() {
        for range ticker.C {
            self.updateGauges()
        }
    }()
}

func (self *Swarm) updateGauges() {
    uptimeGauge.Update(time.Since(startTime).Nanoseconds())
    requestsCacheGauge.Update(int64(self.netStore.RequestsCacheLen()))
}

// implements the node.Service interface
// stops all component services.
func (self *Swarm) Stop() error {
    if self.tracerClose != nil {
        err := self.tracerClose.Close()
        if err != nil {
            return err
        }
    }

    if self.ps != nil {
        self.ps.Stop()
    }
    if ch := self.config.Swap.Chequebook(); ch != nil {
        ch.Stop()
        ch.Save()
    }
    if self.swap != nil {
        self.swap.Close()
    }
    if self.accountingMetrics != nil {
        self.accountingMetrics.Close()
    }
    if self.netStore != nil {
        self.netStore.Close()
    }
    self.sfs.Stop()
    stopCounter.Inc(1)
    self.streamer.Stop()

    err := self.bzz.Stop()
    if self.stateStore != nil {
        self.stateStore.Close()
    }
    return err
}

// implements the node.Service interface
func (self *Swarm) Protocols() (protos []p2p.Protocol) {
    protos = append(protos, self.bzz.Protocols()...)

    if self.ps != nil {
        protos = append(protos, self.ps.Protocols()...)
    }
    return
}

func (self *Swarm) RegisterPssProtocol(spec *protocols.Spec, targetprotocol *p2p.Protocol, options *pss.ProtocolParams) (*pss.Protocol, error) {
    if !pss.IsActiveProtocol {
        return nil, fmt.Errorf("Pss protocols not available (built with !nopssprotocol tag)")
    }
    topic := pss.ProtocolTopic(spec)
    return pss.RegisterProtocol(self.ps, &topic, spec, targetprotocol, options)
}

// implements node.Service
// APIs returns the RPC API descriptors the Swarm implementation offers
func (self *Swarm) APIs() []rpc.API {

    apis := []rpc.API{
        // public APIs
        {
            Namespace: "bzz",
            Version:   "3.0",
            Service:   &Info{self.config, chequebook.ContractParams},
            Public:    true,
        },
        // admin APIs
        {
            Namespace: "bzz",
            Version:   "3.0",
            Service:   api.NewControl(self.api, self.bzz.Hive),
            Public:    false,
        },
        {
            Namespace: "chequebook",
            Version:   chequebook.Version,
            Service:   chequebook.NewApi(self.config.Swap.Chequebook),
            Public:    false,
        },
        {
            Namespace: "swarmfs",
            Version:   fuse.Swarmfs_Version,
            Service:   self.sfs,
            Public:    false,
        },
    }

    apis = append(apis, self.bzz.APIs()...)

    if self.ps != nil {
        apis = append(apis, self.ps.APIs()...)
    }

    return apis
}

func (self *Swarm) Api() *api.API {
    return self.api
}

// SetChequebook ensures that the local checquebook is set up on chain.
func (self *Swarm) SetChequebook(ctx context.Context) error {
    err := self.config.Swap.SetChequebook(ctx, self.backend, self.config.Path)
    if err != nil {
        return err
    }
    log.Info(fmt.Sprintf("new chequebook set (%v): saving config file, resetting all connections in the hive", self.config.Swap.Contract.Hex()))
    return nil
}

// serialisable info about swarm
type Info struct {
    *api.Config
    *chequebook.Params
}

func (self *Info) Info() *Info {
    return self
}