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"
    "time"

    "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/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"
)

// 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, ensClientConfigs []ENSClientConfig, config *api.Config, swapEnabled, syncEnabled bool, cors string) (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: swapEnabled,
        backend:     backend,
        privateKey:  config.Swap.PrivateKey(),
        corsString:  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
        swapEnabled,                          // SWAP enabled
        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(ensClientConfigs) == 1 {
        self.dns, err = newEnsClient(ensClientConfigs[0].Endpoint, ensClientConfigs[0].ContractAddress, config)
        if err != nil {
            return nil, err
        }
    } else if len(ensClientConfigs) > 1 {
        opts := []api.MultiResolverOption{}
        for _, c := range ensClientConfigs {
            r, err := newEnsClient(c.Endpoint, c.ContractAddress, config)
            if err != nil {
                return nil, err
            }
            opts = append(opts, api.MultiResolverOptionWithResolver(r, c.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
}

// ENSClientConfig holds information to construct ENS resolver. If TLD is non-empty,
// the resolver will be used only for that TLD. If ContractAddress is empty,
// it will be discovered by the client, or used one from the configuration.
type ENSClientConfig struct {
    Endpoint        string
    ContractAddress string
    TLD             string
}

// 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, addr string, 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 != "" {
        ensRoot = common.HexToAddress(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 {
    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))
        }
    }

    return nil
}

// implements the node.Service interface
// stops all component services.
func (self *Swarm) Stop() error {
    self.dpa.Stop()
    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()
    return self.config.Save()
}

// 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.config.Save()
    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, err := api.NewConfig(datadir, common.Address{}, prvKey, network.NetworkId)
    if err != nil {
        return
    }
    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
}