path: root/swarm/swarm.go

// Copyright 2016 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"
    "math/big"
    "net"
    "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/crypto"
    "github.com/ethereum/go-ethereum/ethclient"
    "github.com/ethereum/go-ethereum/log"
    "github.com/ethereum/go-ethereum/metrics"
    "github.com/ethereum/go-ethereum/node"
    "github.com/ethereum/go-ethereum/p2p"
    "github.com/ethereum/go-ethereum/p2p/discover"
    "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/network"
    "github.com/ethereum/go-ethereum/swarm/storage"
)

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)
    dbSizeGauge        = metrics.NewRegisteredGauge("storage.db.chunks.size", nil)
    cacheSizeGauge     = metrics.NewRegisteredGauge("storage.db.cache.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
    dbAccess    *network.DbAccess      // access to local chunk db iterator and storage counter
    storage     storage.ChunkStore     // internal access to storage, common interface to cloud storage backends
    dpa         *storage.DPA           // distributed preimage archive, the local API to the storage with document level storage/retrieval support
    depo        network.StorageHandler // remote request handler, interface between bzz protocol and the storage
    cloud       storage.CloudStore     // procurement, cloud storage backend (can multi-cloud)
    hive        *network.Hive          // the logistic manager
    backend     chequebook.Backend     // simple blockchain Backend
    privateKey  *ecdsa.PrivateKey
    corsString  string
    swapEnabled bool
    lstore      *storage.LocalStore // local store, needs to store for releasing resources after node stopped
    sfs         *fuse.SwarmFS       // need this to cleanup all the active mounts on node exit
}

type SwarmAPI struct {
    Api     *api.Api
    Backend chequebook.Backend
    PrvKey  *ecdsa.PrivateKey
}

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

// creates a new swarm service instance
// implements node.Service
func NewSwarm(ctx *node.ServiceContext, backend chequebook.Backend, config *api.Config) (self *Swarm, err error) {
    if bytes.Equal(common.FromHex(config.PublicKey), storage.ZeroKey) {
        return nil, fmt.Errorf("empty public key")
    }
    if bytes.Equal(common.FromHex(config.BzzKey), storage.ZeroKey) {
        return nil, fmt.Errorf("empty bzz key")
    }

    self = &Swarm{
        config:      config,
        swapEnabled: config.SwapEnabled,
        backend:     backend,
        privateKey:  config.Swap.PrivateKey(),
        corsString:  config.Cors,
    }
    log.Debug(fmt.Sprintf("Setting up Swarm service components"))

    hash := storage.MakeHashFunc(config.ChunkerParams.Hash)
    self.lstore, err = storage.NewLocalStore(hash, config.StoreParams)
    if err != nil {
        return
    }

    // setup local store
    log.Debug(fmt.Sprintf("Set up local storage"))

    self.dbAccess = network.NewDbAccess(self.lstore)
    log.Debug(fmt.Sprintf("Set up local db access (iterator/counter)"))

    // set up the kademlia hive
    self.hive = network.NewHive(
        common.HexToHash(self.config.BzzKey), // key to hive (kademlia base address)
        config.HiveParams,                    // configuration parameters
        config.SwapEnabled,                   // SWAP enabled
        config.SyncEnabled,                   // syncronisation enabled
    )
    log.Debug(fmt.Sprintf("Set up swarm network with Kademlia hive"))

    // setup cloud storage backend
    self.cloud = network.NewForwarder(self.hive)
    log.Debug(fmt.Sprintf("-> set swarm forwarder as cloud storage backend"))

    // setup cloud storage internal access layer
    self.storage = storage.NewNetStore(hash, self.lstore, self.cloud, config.StoreParams)
    log.Debug(fmt.Sprintf("-> swarm net store shared access layer to Swarm Chunk Store"))

    // set up Depo (storage handler = cloud storage access layer for incoming remote requests)
    self.depo = network.NewDepo(hash, self.lstore, self.storage)
    log.Debug(fmt.Sprintf("-> REmote Access to CHunks"))

    // set up DPA, the cloud storage local access layer
    dpaChunkStore := storage.NewDpaChunkStore(self.lstore, self.storage)
    log.Debug(fmt.Sprintf("-> Local Access to Swarm"))
    // Swarm Hash Merklised Chunking for Arbitrary-length Document/File storage
    self.dpa = storage.NewDPA(dpaChunkStore, self.config.ChunkerParams)
    log.Debug(fmt.Sprintf("-> Content Store API"))

    if len(config.EnsAPIs) > 0 {
        opts := []api.MultiResolverOption{}
        for _, c := range config.EnsAPIs {
            tld, endpoint, addr := parseEnsAPIAddress(c)
            r, err := newEnsClient(endpoint, addr, config)
            if err != nil {
                return nil, err
            }
            opts = append(opts, api.MultiResolverOptionWithResolver(r, tld))
        }
        self.dns = api.NewMultiResolver(opts...)
    }

    self.api = api.NewApi(self.dpa, self.dns)
    // Manifests for Smart Hosting
    log.Debug(fmt.Sprintf("-> Web3 virtual server API"))

    self.sfs = fuse.NewSwarmFS(self.api)
    log.Debug("-> Initializing Fuse file system")

    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
}

// 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) (*ens.ENS, 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)
    }
    ensClient := 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(config.Swap.PrivateKey())
    dns, err := ens.NewENS(transactOpts, ensRoot, ensClient)
    if err != nil {
        return nil, err
    }
    log.Debug(fmt.Sprintf("-> Swarm Domain Name Registrar %v @ address %v", endpoint, ensRoot.Hex()))
    return dns, 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()
    connectPeer := func(url string) error {
        node, err := discover.ParseNode(url)
        if err != nil {
            return fmt.Errorf("invalid node URL: %v", err)
        }
        srv.AddPeer(node)
        return nil
    }
    // set chequebook
    if self.swapEnabled {
        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.Warn(fmt.Sprintf("Starting Swarm service"))
    self.hive.Start(
        discover.PubkeyID(&srv.PrivateKey.PublicKey),
        func() string { return srv.ListenAddr },
        connectPeer,
    )
    log.Info(fmt.Sprintf("Swarm network started on bzz address: %v", self.hive.Addr()))

    self.dpa.Start()
    log.Debug(fmt.Sprintf("Swarm DPA started"))

    // start swarm http proxy server
    if self.config.Port != "" {
        addr := net.JoinHostPort(self.config.ListenAddr, self.config.Port)
        go httpapi.StartHttpServer(self.api, &httpapi.ServerConfig{
            Addr:       addr,
            CorsString: self.corsString,
        })
        log.Info(fmt.Sprintf("Swarm http proxy started on %v", addr))

        if self.corsString != "" {
            log.Debug(fmt.Sprintf("Swarm http proxy started with corsdomain: %v", self.corsString))
        }
    }

    self.periodicallyUpdateGauges()

    startCounter.Inc(1)
    return nil
}

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

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

func (self *Swarm) updateGauges() {
    dbSizeGauge.Update(int64(self.lstore.DbCounter()))
    cacheSizeGauge.Update(int64(self.lstore.CacheCounter()))
    uptimeGauge.Update(time.Since(startTime).Nanoseconds())
}

// implements the node.Service interface
// stops all component services.
func (self *Swarm) Stop() error {
    self.dpa.Stop()
    err := self.hive.Stop()
    if ch := self.config.Swap.Chequebook(); ch != nil {
        ch.Stop()
        ch.Save()
    }

    if self.lstore != nil {
        self.lstore.DbStore.Close()
    }
    self.sfs.Stop()
    stopCounter.Inc(1)
    return err
}

// implements the node.Service interface
func (self *Swarm) Protocols() []p2p.Protocol {
    proto, err := network.Bzz(self.depo, self.backend, self.hive, self.dbAccess, self.config.Swap, self.config.SyncParams, self.config.NetworkId)
    if err != nil {
        return nil
    }
    return []p2p.Protocol{proto}
}

// implements node.Service
// Apis returns the RPC Api descriptors the Swarm implementation offers
func (self *Swarm) APIs() []rpc.API {
    return []rpc.API{
        // public APIs
        {
            Namespace: "bzz",
            Version:   "0.1",
            Service:   &Info{self.config, chequebook.ContractParams},
            Public:    true,
        },
        // admin APIs
        {
            Namespace: "bzz",
            Version:   "0.1",
            Service:   api.NewControl(self.api, self.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,
        },
        // storage APIs
        // DEPRECATED: Use the HTTP API instead
        {
            Namespace: "bzz",
            Version:   "0.1",
            Service:   api.NewStorage(self.api),
            Public:    true,
        },
        {
            Namespace: "bzz",
            Version:   "0.1",
            Service:   api.NewFileSystem(self.api),
            Public:    false,
        },
        // {Namespace, Version, api.NewAdmin(self), false},
    }
}

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()))
    self.hive.DropAll()
    return nil
}

// Local swarm without netStore
func NewLocalSwarm(datadir, port string) (self *Swarm, err error) {

    prvKey, err := crypto.GenerateKey()
    if err != nil {
        return
    }

    config := api.NewDefaultConfig()
    config.Path = datadir
    config.Init(prvKey)
    config.Port = port

    dpa, err := storage.NewLocalDPA(datadir)
    if err != nil {
        return
    }

    self = &Swarm{
        api:    api.NewApi(dpa, nil),
        config: config,
    }

    return
}

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

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