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-rw-r--r--swarm/storage/mru/resource.go1066
1 files changed, 1066 insertions, 0 deletions
diff --git a/swarm/storage/mru/resource.go b/swarm/storage/mru/resource.go
new file mode 100644
index 000000000..1e92a5e92
--- /dev/null
+++ b/swarm/storage/mru/resource.go
@@ -0,0 +1,1066 @@
+// 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 mru
+
+import (
+ "bytes"
+ "context"
+ "encoding/binary"
+ "errors"
+ "fmt"
+ "math/big"
+ "path/filepath"
+ "sync"
+ "time"
+
+ "golang.org/x/net/idna"
+
+ "github.com/ethereum/go-ethereum/common"
+ "github.com/ethereum/go-ethereum/contracts/ens"
+ "github.com/ethereum/go-ethereum/core/types"
+ "github.com/ethereum/go-ethereum/crypto"
+ "github.com/ethereum/go-ethereum/swarm/log"
+ "github.com/ethereum/go-ethereum/swarm/multihash"
+ "github.com/ethereum/go-ethereum/swarm/storage"
+)
+
+const (
+ signatureLength = 65
+ metadataChunkOffsetSize = 18
+ DbDirName = "resource"
+ chunkSize = 4096 // temporary until we implement FileStore in the resourcehandler
+ defaultStoreTimeout = 4000 * time.Millisecond
+ hasherCount = 8
+ resourceHash = storage.SHA3Hash
+ defaultRetrieveTimeout = 100 * time.Millisecond
+)
+
+type blockEstimator struct {
+ Start time.Time
+ Average time.Duration
+}
+
+// TODO: Average must be adjusted when blockchain connection is present and synced
+func NewBlockEstimator() *blockEstimator {
+ sampleDate, _ := time.Parse(time.RFC3339, "2018-05-04T20:35:22Z") // from etherscan.io
+ sampleBlock := int64(3169691) // from etherscan.io
+ ropstenStart, _ := time.Parse(time.RFC3339, "2016-11-20T11:48:50Z") // from etherscan.io
+ ns := sampleDate.Sub(ropstenStart).Nanoseconds()
+ period := int(ns / sampleBlock)
+ parsestring := fmt.Sprintf("%dns", int(float64(period)*1.0005)) // increase the blockcount a little, so we don't overshoot the read block height; if we do, we will never find the updates when getting synced data
+ periodNs, _ := time.ParseDuration(parsestring)
+ return &blockEstimator{
+ Start: ropstenStart,
+ Average: periodNs,
+ }
+}
+
+func (b *blockEstimator) HeaderByNumber(context.Context, string, *big.Int) (*types.Header, error) {
+ return &types.Header{
+ Number: big.NewInt(time.Since(b.Start).Nanoseconds() / b.Average.Nanoseconds()),
+ }, nil
+}
+
+type Error struct {
+ code int
+ err string
+}
+
+func (e *Error) Error() string {
+ return e.err
+}
+
+func (e *Error) Code() int {
+ return e.code
+}
+
+func NewError(code int, s string) error {
+ if code < 0 || code >= ErrCnt {
+ panic("no such error code!")
+ }
+ r := &Error{
+ err: s,
+ }
+ switch code {
+ case ErrNotFound, ErrIO, ErrUnauthorized, ErrInvalidValue, ErrDataOverflow, ErrNothingToReturn, ErrInvalidSignature, ErrNotSynced, ErrPeriodDepth, ErrCorruptData:
+ r.code = code
+ }
+ return r
+}
+
+type Signature [signatureLength]byte
+
+type LookupParams struct {
+ Limit bool
+ Max uint32
+}
+
+// Encapsulates an specific resource update. When synced it contains the most recent
+// version of the resource update data.
+type resource struct {
+ *bytes.Reader
+ Multihash bool
+ name string
+ nameHash common.Hash
+ startBlock uint64
+ lastPeriod uint32
+ lastKey storage.Address
+ frequency uint64
+ version uint32
+ data []byte
+ updated time.Time
+}
+
+// TODO Expire content after a defined period (to force resync)
+func (r *resource) isSynced() bool {
+ return !r.updated.IsZero()
+}
+
+func (r *resource) NameHash() common.Hash {
+ return r.nameHash
+}
+
+func (r *resource) Size(chan bool) (int64, error) {
+ if !r.isSynced() {
+ return 0, NewError(ErrNotSynced, "Not synced")
+ }
+ return int64(len(r.data)), nil
+}
+
+func (r *resource) Name() string {
+ return r.name
+}
+
+func (r *resource) UnmarshalBinary(data []byte) error {
+ r.startBlock = binary.LittleEndian.Uint64(data[:8])
+ r.frequency = binary.LittleEndian.Uint64(data[8:16])
+ r.name = string(data[16:])
+ return nil
+}
+
+func (r *resource) MarshalBinary() ([]byte, error) {
+ b := make([]byte, 16+len(r.name))
+ binary.LittleEndian.PutUint64(b, r.startBlock)
+ binary.LittleEndian.PutUint64(b[8:], r.frequency)
+ copy(b[16:], []byte(r.name))
+ return b, nil
+}
+
+type headerGetter interface {
+ HeaderByNumber(context.Context, string, *big.Int) (*types.Header, error)
+}
+
+type ownerValidator interface {
+ ValidateOwner(name string, address common.Address) (bool, error)
+}
+
+// Mutable resource is an entity which allows updates to a resource
+// without resorting to ENS on each update.
+// The update scheme is built on swarm chunks with chunk keys following
+// a predictable, versionable pattern.
+//
+// Updates are defined to be periodic in nature, where periods are
+// expressed in terms of number of blocks.
+//
+// The root entry of a mutable resource is tied to a unique identifier,
+// typically - but not necessarily - an ens name. The identifier must be
+// an valid IDNA string. It also contains the block number
+// when the resource update was first registered, and
+// the block frequency with which the resource will be updated, both of
+// which are stored as little-endian uint64 values in the database (for a
+// total of 16 bytes). It also contains the unique identifier.
+// It is stored in a separate content-addressed chunk (call it the metadata chunk),
+// with the following layout:
+//
+// (0x0000|startblock|frequency|identifier)
+//
+// (The two first zero-value bytes are used for disambiguation by the chunk validator,
+// and update chunk will always have a value > 0 there.)
+//
+// The root entry tells the requester from when the mutable resource was
+// first added (block number) and in which block number to look for the
+// actual updates. Thus, a resource update for identifier "føø.bar"
+// starting at block 4200 with frequency 42 will have updates on block 4242,
+// 4284, 4326 and so on.
+//
+// Actual data updates are also made in the form of swarm chunks. The keys
+// of the updates are the hash of a concatenation of properties as follows:
+//
+// sha256(period|version|namehash)
+//
+// The period is (currentblock - startblock) / frequency
+//
+// Using our previous example, this means that a period 3 will have 4326 as
+// the block number.
+//
+// If more than one update is made to the same block number, incremental
+// version numbers are used successively.
+//
+// A lookup agent need only know the identifier name in order to get the versions
+//
+// the resourcedata is:
+// headerlength|period|version|identifier|data
+//
+// if a validator is active, the chunk data is:
+// resourcedata|sign(resourcedata)
+// otherwise, the chunk data is the same as the resourcedata
+//
+// headerlength is a 16 bit value containing the byte length of period|version|name
+//
+// TODO: Include modtime in chunk data + signature
+type Handler struct {
+ chunkStore *storage.NetStore
+ HashSize int
+ signer Signer
+ headerGetter headerGetter
+ ownerValidator ownerValidator
+ resources map[string]*resource
+ hashPool sync.Pool
+ resourceLock sync.RWMutex
+ storeTimeout time.Duration
+ queryMaxPeriods *LookupParams
+}
+
+type HandlerParams struct {
+ QueryMaxPeriods *LookupParams
+ Signer Signer
+ HeaderGetter headerGetter
+ OwnerValidator ownerValidator
+}
+
+// Create or open resource update chunk store
+func NewHandler(params *HandlerParams) (*Handler, error) {
+ if params.QueryMaxPeriods == nil {
+ params.QueryMaxPeriods = &LookupParams{
+ Limit: false,
+ }
+ }
+ rh := &Handler{
+ headerGetter: params.HeaderGetter,
+ ownerValidator: params.OwnerValidator,
+ resources: make(map[string]*resource),
+ storeTimeout: defaultStoreTimeout,
+ signer: params.Signer,
+ hashPool: sync.Pool{
+ New: func() interface{} {
+ return storage.MakeHashFunc(resourceHash)()
+ },
+ },
+ queryMaxPeriods: params.QueryMaxPeriods,
+ }
+
+ for i := 0; i < hasherCount; i++ {
+ hashfunc := storage.MakeHashFunc(resourceHash)()
+ if rh.HashSize == 0 {
+ rh.HashSize = hashfunc.Size()
+ }
+ rh.hashPool.Put(hashfunc)
+ }
+
+ return rh, nil
+}
+
+// SetStore sets the store backend for resource updates
+func (h *Handler) SetStore(store *storage.NetStore) {
+ h.chunkStore = store
+}
+
+// Validate is a chunk validation method (matches ChunkValidatorFunc signature)
+//
+// If resource update, owner is checked against ENS record of resource name inferred from chunk data
+// If parsed signature is nil, validates automatically
+// If not resource update, it validates are root chunk if length is metadataChunkOffsetSize and first two bytes are 0
+func (h *Handler) Validate(addr storage.Address, data []byte) bool {
+ signature, period, version, name, parseddata, _, err := h.parseUpdate(data)
+ if err != nil {
+ log.Warn(err.Error())
+ if len(data) > metadataChunkOffsetSize { // identifier comes after this byte range, and must be at least one byte
+ if bytes.Equal(data[:2], []byte{0, 0}) {
+ return true
+ }
+ }
+ log.Error("Invalid resource chunk")
+ return false
+ } else if signature == nil {
+ return bytes.Equal(h.resourceHash(period, version, ens.EnsNode(name)), addr)
+ }
+
+ digest := h.keyDataHash(addr, parseddata)
+ addrSig, err := getAddressFromDataSig(digest, *signature)
+ if err != nil {
+ log.Error("Invalid signature on resource chunk")
+ return false
+ }
+ ok, _ := h.checkAccess(name, addrSig)
+ return ok
+}
+
+// If no ens client is supplied, resource updates are not validated
+func (h *Handler) IsValidated() bool {
+ return h.ownerValidator != nil
+}
+
+// Create the resource update digest used in signatures
+func (h *Handler) keyDataHash(addr storage.Address, data []byte) common.Hash {
+ hasher := h.hashPool.Get().(storage.SwarmHash)
+ defer h.hashPool.Put(hasher)
+ hasher.Reset()
+ hasher.Write(addr[:])
+ hasher.Write(data)
+ return common.BytesToHash(hasher.Sum(nil))
+}
+
+// Checks if current address matches owner address of ENS
+func (h *Handler) checkAccess(name string, address common.Address) (bool, error) {
+ if h.ownerValidator == nil {
+ return true, nil
+ }
+ return h.ownerValidator.ValidateOwner(name, address)
+}
+
+// get data from current resource
+func (h *Handler) GetContent(name string) (storage.Address, []byte, error) {
+ rsrc := h.get(name)
+ if rsrc == nil || !rsrc.isSynced() {
+ return nil, nil, NewError(ErrNotFound, " does not exist or is not synced")
+ }
+ return rsrc.lastKey, rsrc.data, nil
+}
+
+// Gets the period of the current data loaded in the resource
+func (h *Handler) GetLastPeriod(nameHash string) (uint32, error) {
+ rsrc := h.get(nameHash)
+ if rsrc == nil {
+ return 0, NewError(ErrNotFound, " does not exist")
+ } else if !rsrc.isSynced() {
+ return 0, NewError(ErrNotSynced, " is not synced")
+ }
+ return rsrc.lastPeriod, nil
+}
+
+// Gets the version of the current data loaded in the resource
+func (h *Handler) GetVersion(nameHash string) (uint32, error) {
+ rsrc := h.get(nameHash)
+ if rsrc == nil {
+ return 0, NewError(ErrNotFound, " does not exist")
+ } else if !rsrc.isSynced() {
+ return 0, NewError(ErrNotSynced, " is not synced")
+ }
+ return rsrc.version, nil
+}
+
+// \TODO should be hashsize * branches from the chosen chunker, implement with FileStore
+func (h *Handler) chunkSize() int64 {
+ return chunkSize
+}
+
+// Creates a new root entry for a mutable resource identified by `name` with the specified `frequency`.
+//
+// The signature data should match the hash of the idna-converted name by the validator's namehash function, NOT the raw name bytes.
+//
+// The start block of the resource update will be the actual current block height of the connected network.
+func (h *Handler) New(ctx context.Context, name string, frequency uint64) (storage.Address, *resource, error) {
+
+ // frequency 0 is invalid
+ if frequency == 0 {
+ return nil, nil, NewError(ErrInvalidValue, "Frequency cannot be 0")
+ }
+
+ // make sure name only contains ascii values
+ if !isSafeName(name) {
+ return nil, nil, NewError(ErrInvalidValue, fmt.Sprintf("Invalid name: '%s'", name))
+ }
+
+ nameHash := ens.EnsNode(name)
+
+ // if the signer function is set, validate that the key of the signer has access to modify this ENS name
+ if h.signer != nil {
+ signature, err := h.signer.Sign(nameHash)
+ if err != nil {
+ return nil, nil, NewError(ErrInvalidSignature, fmt.Sprintf("Sign fail: %v", err))
+ }
+ addr, err := getAddressFromDataSig(nameHash, signature)
+ if err != nil {
+ return nil, nil, NewError(ErrInvalidSignature, fmt.Sprintf("Retrieve address from signature fail: %v", err))
+ }
+ ok, err := h.checkAccess(name, addr)
+ if err != nil {
+ return nil, nil, err
+ } else if !ok {
+ return nil, nil, NewError(ErrUnauthorized, fmt.Sprintf("Not owner of '%s'", name))
+ }
+ }
+
+ // get our blockheight at this time
+ currentblock, err := h.getBlock(ctx, name)
+ if err != nil {
+ return nil, nil, err
+ }
+
+ chunk := h.newMetaChunk(name, currentblock, frequency)
+
+ h.chunkStore.Put(chunk)
+ log.Debug("new resource", "name", name, "key", nameHash, "startBlock", currentblock, "frequency", frequency)
+
+ // create the internal index for the resource and populate it with the data of the first version
+ rsrc := &resource{
+ startBlock: currentblock,
+ frequency: frequency,
+ name: name,
+ nameHash: nameHash,
+ updated: time.Now(),
+ }
+ h.set(nameHash.Hex(), rsrc)
+
+ return chunk.Addr, rsrc, nil
+}
+
+func (h *Handler) newMetaChunk(name string, startBlock uint64, frequency uint64) *storage.Chunk {
+ // the metadata chunk points to data of first blockheight + update frequency
+ // from this we know from what blockheight we should look for updates, and how often
+ // it also contains the name of the resource, so we know what resource we are working with
+ data := make([]byte, metadataChunkOffsetSize+len(name))
+
+ // root block has first two bytes both set to 0, which distinguishes from update bytes
+ val := make([]byte, 8)
+ binary.LittleEndian.PutUint64(val, startBlock)
+ copy(data[2:10], val)
+ binary.LittleEndian.PutUint64(val, frequency)
+ copy(data[10:18], val)
+ copy(data[18:], []byte(name))
+
+ // the key of the metadata chunk is content-addressed
+ // if it wasn't we couldn't replace it later
+ // resolving this relationship is left up to external agents (for example ENS)
+ hasher := h.hashPool.Get().(storage.SwarmHash)
+ hasher.Reset()
+ hasher.Write(data)
+ key := hasher.Sum(nil)
+ h.hashPool.Put(hasher)
+
+ // make the chunk and send it to swarm
+ chunk := storage.NewChunk(key, nil)
+ chunk.SData = make([]byte, metadataChunkOffsetSize+len(name))
+ copy(chunk.SData, data)
+ return chunk
+}
+
+// Searches and retrieves the specific version of the resource update identified by `name`
+// at the specific block height
+//
+// If refresh is set to true, the resource data will be reloaded from the resource update
+// metadata chunk.
+// It is the callers responsibility to make sure that this chunk exists (if the resource
+// update root data was retrieved externally, it typically doesn't)
+func (h *Handler) LookupVersionByName(ctx context.Context, name string, period uint32, version uint32, refresh bool, maxLookup *LookupParams) (*resource, error) {
+ return h.LookupVersion(ctx, ens.EnsNode(name), period, version, refresh, maxLookup)
+}
+
+func (h *Handler) LookupVersion(ctx context.Context, nameHash common.Hash, period uint32, version uint32, refresh bool, maxLookup *LookupParams) (*resource, error) {
+ rsrc := h.get(nameHash.Hex())
+ if rsrc == nil {
+ return nil, NewError(ErrNothingToReturn, "resource not loaded")
+ }
+ return h.lookup(rsrc, period, version, refresh, maxLookup)
+}
+
+// Retrieves the latest version of the resource update identified by `name`
+// at the specified block height
+//
+// If an update is found, version numbers are iterated until failure, and the last
+// successfully retrieved version is copied to the corresponding resources map entry
+// and returned.
+//
+// See also (*Handler).LookupVersion
+func (h *Handler) LookupHistoricalByName(ctx context.Context, name string, period uint32, refresh bool, maxLookup *LookupParams) (*resource, error) {
+ return h.LookupHistorical(ctx, ens.EnsNode(name), period, refresh, maxLookup)
+}
+
+func (h *Handler) LookupHistorical(ctx context.Context, nameHash common.Hash, period uint32, refresh bool, maxLookup *LookupParams) (*resource, error) {
+ rsrc := h.get(nameHash.Hex())
+ if rsrc == nil {
+ return nil, NewError(ErrNothingToReturn, "resource not loaded")
+ }
+ return h.lookup(rsrc, period, 0, refresh, maxLookup)
+}
+
+// Retrieves the latest version of the resource update identified by `name`
+// at the next update block height
+//
+// It starts at the next period after the current block height, and upon failure
+// tries the corresponding keys of each previous period until one is found
+// (or startBlock is reached, in which case there are no updates).
+//
+// Version iteration is done as in (*Handler).LookupHistorical
+//
+// See also (*Handler).LookupHistorical
+func (h *Handler) LookupLatestByName(ctx context.Context, name string, refresh bool, maxLookup *LookupParams) (*resource, error) {
+ return h.LookupLatest(ctx, ens.EnsNode(name), refresh, maxLookup)
+}
+
+func (h *Handler) LookupLatest(ctx context.Context, nameHash common.Hash, refresh bool, maxLookup *LookupParams) (*resource, error) {
+
+ // get our blockheight at this time and the next block of the update period
+ rsrc := h.get(nameHash.Hex())
+ if rsrc == nil {
+ return nil, NewError(ErrNothingToReturn, "resource not loaded")
+ }
+ currentblock, err := h.getBlock(ctx, rsrc.name)
+ if err != nil {
+ return nil, err
+ }
+ nextperiod, err := getNextPeriod(rsrc.startBlock, currentblock, rsrc.frequency)
+ if err != nil {
+ return nil, err
+ }
+ return h.lookup(rsrc, nextperiod, 0, refresh, maxLookup)
+}
+
+// Returns the resource before the one currently loaded in the resource index
+//
+// This is useful where resource updates are used incrementally in contrast to
+// merely replacing content.
+//
+// Requires a synced resource object
+func (h *Handler) LookupPreviousByName(ctx context.Context, name string, maxLookup *LookupParams) (*resource, error) {
+ return h.LookupPrevious(ctx, ens.EnsNode(name), maxLookup)
+}
+
+func (h *Handler) LookupPrevious(ctx context.Context, nameHash common.Hash, maxLookup *LookupParams) (*resource, error) {
+ rsrc := h.get(nameHash.Hex())
+ if rsrc == nil {
+ return nil, NewError(ErrNothingToReturn, "resource not loaded")
+ }
+ if !rsrc.isSynced() {
+ return nil, NewError(ErrNotSynced, "LookupPrevious requires synced resource.")
+ } else if rsrc.lastPeriod == 0 {
+ return nil, NewError(ErrNothingToReturn, " not found")
+ }
+ if rsrc.version > 1 {
+ rsrc.version--
+ } else if rsrc.lastPeriod == 1 {
+ return nil, NewError(ErrNothingToReturn, "Current update is the oldest")
+ } else {
+ rsrc.version = 0
+ rsrc.lastPeriod--
+ }
+ return h.lookup(rsrc, rsrc.lastPeriod, rsrc.version, false, maxLookup)
+}
+
+// base code for public lookup methods
+func (h *Handler) lookup(rsrc *resource, period uint32, version uint32, refresh bool, maxLookup *LookupParams) (*resource, error) {
+
+ // we can't look for anything without a store
+ if h.chunkStore == nil {
+ return nil, NewError(ErrInit, "Call Handler.SetStore() before performing lookups")
+ }
+
+ // period 0 does not exist
+ if period == 0 {
+ return nil, NewError(ErrInvalidValue, "period must be >0")
+ }
+
+ // start from the last possible block period, and iterate previous ones until we find a match
+ // if we hit startBlock we're out of options
+ var specificversion bool
+ if version > 0 {
+ specificversion = true
+ } else {
+ version = 1
+ }
+
+ var hops uint32
+ if maxLookup == nil {
+ maxLookup = h.queryMaxPeriods
+ }
+ log.Trace("resource lookup", "period", period, "version", version, "limit", maxLookup.Limit, "max", maxLookup.Max)
+ for period > 0 {
+ if maxLookup.Limit && hops > maxLookup.Max {
+ return nil, NewError(ErrPeriodDepth, fmt.Sprintf("Lookup exceeded max period hops (%d)", maxLookup.Max))
+ }
+ key := h.resourceHash(period, version, rsrc.nameHash)
+ chunk, err := h.chunkStore.GetWithTimeout(key, defaultRetrieveTimeout)
+ if err == nil {
+ if specificversion {
+ return h.updateIndex(rsrc, chunk)
+ }
+ // check if we have versions > 1. If a version fails, the previous version is used and returned.
+ log.Trace("rsrc update version 1 found, checking for version updates", "period", period, "key", key)
+ for {
+ newversion := version + 1
+ key := h.resourceHash(period, newversion, rsrc.nameHash)
+ newchunk, err := h.chunkStore.GetWithTimeout(key, defaultRetrieveTimeout)
+ if err != nil {
+ return h.updateIndex(rsrc, chunk)
+ }
+ chunk = newchunk
+ version = newversion
+ log.Trace("version update found, checking next", "version", version, "period", period, "key", key)
+ }
+ }
+ log.Trace("rsrc update not found, checking previous period", "period", period, "key", key)
+ period--
+ hops++
+ }
+ return nil, NewError(ErrNotFound, "no updates found")
+}
+
+// Retrieves a resource metadata chunk and creates/updates the index entry for it
+// with the resulting metadata
+func (h *Handler) Load(addr storage.Address) (*resource, error) {
+ chunk, err := h.chunkStore.GetWithTimeout(addr, defaultRetrieveTimeout)
+ if err != nil {
+ return nil, NewError(ErrNotFound, err.Error())
+ }
+
+ // minimum sanity check for chunk data (an update chunk first two bytes is headerlength uint16, and cannot be 0)
+ // \TODO this is not enough to make sure the data isn't bogus. A normal content addressed chunk could still satisfy these criteria
+ if !bytes.Equal(chunk.SData[:2], []byte{0x0, 0x0}) {
+ return nil, NewError(ErrCorruptData, fmt.Sprintf("Chunk is not a resource metadata chunk"))
+ } else if len(chunk.SData) <= metadataChunkOffsetSize {
+ return nil, NewError(ErrNothingToReturn, fmt.Sprintf("Invalid chunk length %d, should be minimum %d", len(chunk.SData), metadataChunkOffsetSize+1))
+ }
+
+ // create the index entry
+ rsrc := &resource{}
+ rsrc.UnmarshalBinary(chunk.SData[2:])
+ rsrc.nameHash = ens.EnsNode(rsrc.name)
+ h.set(rsrc.nameHash.Hex(), rsrc)
+ log.Trace("resource index load", "rootkey", addr, "name", rsrc.name, "namehash", rsrc.nameHash, "startblock", rsrc.startBlock, "frequency", rsrc.frequency)
+ return rsrc, nil
+}
+
+// update mutable resource index map with specified content
+func (h *Handler) updateIndex(rsrc *resource, chunk *storage.Chunk) (*resource, error) {
+
+ // retrieve metadata from chunk data and check that it matches this mutable resource
+ signature, period, version, name, data, multihash, err := h.parseUpdate(chunk.SData)
+ if rsrc.name != name {
+ return nil, NewError(ErrNothingToReturn, fmt.Sprintf("Update belongs to '%s', but have '%s'", name, rsrc.name))
+ }
+ log.Trace("resource index update", "name", rsrc.name, "namehash", rsrc.nameHash, "updatekey", chunk.Addr, "period", period, "version", version)
+
+ // check signature (if signer algorithm is present)
+ // \TODO maybe this check is redundant if also checked upon retrieval of chunk
+ if signature != nil {
+ digest := h.keyDataHash(chunk.Addr, data)
+ _, err = getAddressFromDataSig(digest, *signature)
+ if err != nil {
+ return nil, NewError(ErrUnauthorized, fmt.Sprintf("Invalid signature: %v", err))
+ }
+ }
+
+ // update our rsrcs entry map
+ rsrc.lastKey = chunk.Addr
+ rsrc.lastPeriod = period
+ rsrc.version = version
+ rsrc.updated = time.Now()
+ rsrc.data = make([]byte, len(data))
+ rsrc.Multihash = multihash
+ rsrc.Reader = bytes.NewReader(rsrc.data)
+ copy(rsrc.data, data)
+ log.Debug(" synced", "name", rsrc.name, "key", chunk.Addr, "period", rsrc.lastPeriod, "version", rsrc.version)
+ h.set(rsrc.nameHash.Hex(), rsrc)
+ return rsrc, nil
+}
+
+// retrieve update metadata from chunk data
+// mirrors newUpdateChunk()
+func (h *Handler) parseUpdate(chunkdata []byte) (*Signature, uint32, uint32, string, []byte, bool, error) {
+ // absolute minimum an update chunk can contain:
+ // 14 = header + one byte of name + one byte of data
+ if len(chunkdata) < 14 {
+ return nil, 0, 0, "", nil, false, NewError(ErrNothingToReturn, "chunk less than 13 bytes cannot be a resource update chunk")
+ }
+ cursor := 0
+ headerlength := binary.LittleEndian.Uint16(chunkdata[cursor : cursor+2])
+ cursor += 2
+ datalength := binary.LittleEndian.Uint16(chunkdata[cursor : cursor+2])
+ cursor += 2
+ var exclsignlength int
+ // we need extra magic if it's a multihash, since we used datalength 0 in header as an indicator of multihash content
+ // retrieve the second varint and set this as the data length
+ // TODO: merge with isMultihash code
+ if datalength == 0 {
+ uvarintbuf := bytes.NewBuffer(chunkdata[headerlength+4:])
+ r, err := binary.ReadUvarint(uvarintbuf)
+ if err != nil {
+ errstr := fmt.Sprintf("corrupt multihash, hash id varint could not be read: %v", err)
+ log.Warn(errstr)
+ return nil, 0, 0, "", nil, false, NewError(ErrCorruptData, errstr)
+
+ }
+ r, err = binary.ReadUvarint(uvarintbuf)
+ if err != nil {
+ errstr := fmt.Sprintf("corrupt multihash, hash length field could not be read: %v", err)
+ log.Warn(errstr)
+ return nil, 0, 0, "", nil, false, NewError(ErrCorruptData, errstr)
+
+ }
+ exclsignlength = int(headerlength + uint16(r))
+ } else {
+ exclsignlength = int(headerlength + datalength + 4)
+ }
+
+ // the total length excluding signature is headerlength and datalength fields plus the length of the header and the data given in these fields
+ exclsignlength = int(headerlength + datalength + 4)
+ if exclsignlength > len(chunkdata) || exclsignlength < 14 {
+ return nil, 0, 0, "", nil, false, NewError(ErrNothingToReturn, fmt.Sprintf("Reported headerlength %d + datalength %d longer than actual chunk data length %d", headerlength, exclsignlength, len(chunkdata)))
+ } else if exclsignlength < 14 {
+ return nil, 0, 0, "", nil, false, NewError(ErrNothingToReturn, fmt.Sprintf("Reported headerlength %d + datalength %d is smaller than minimum valid resource chunk length %d", headerlength, datalength, 14))
+ }
+
+ // at this point we can be satisfied that the data integrity is ok
+ var period uint32
+ var version uint32
+ var name string
+ var data []byte
+ period = binary.LittleEndian.Uint32(chunkdata[cursor : cursor+4])
+ cursor += 4
+ version = binary.LittleEndian.Uint32(chunkdata[cursor : cursor+4])
+ cursor += 4
+ namelength := int(headerlength) - cursor + 4
+ if l := len(chunkdata); l < cursor+namelength {
+ return nil, 0, 0, "", nil, false, NewError(ErrNothingToReturn, fmt.Sprintf("chunk less than %v bytes is too short to read the name", l))
+ }
+ name = string(chunkdata[cursor : cursor+namelength])
+ cursor += namelength
+
+ // if multihash content is indicated we check the validity of the multihash
+ // \TODO the check above for multihash probably is sufficient also for this case (or can be with a small adjustment) and if so this code should be removed
+ var intdatalength int
+ var ismultihash bool
+ if datalength == 0 {
+ var intheaderlength int
+ var err error
+ intdatalength, intheaderlength, err = multihash.GetMultihashLength(chunkdata[cursor:])
+ if err != nil {
+ log.Error("multihash parse error", "err", err)
+ return nil, 0, 0, "", nil, false, err
+ }
+ intdatalength += intheaderlength
+ multihashboundary := cursor + intdatalength
+ if len(chunkdata) != multihashboundary && len(chunkdata) < multihashboundary+signatureLength {
+ log.Debug("multihash error", "chunkdatalen", len(chunkdata), "multihashboundary", multihashboundary)
+ return nil, 0, 0, "", nil, false, errors.New("Corrupt multihash data")
+ }
+ ismultihash = true
+ } else {
+ intdatalength = int(datalength)
+ }
+ data = make([]byte, intdatalength)
+ copy(data, chunkdata[cursor:cursor+intdatalength])
+
+ // omit signatures if we have no validator
+ var signature *Signature
+ cursor += intdatalength
+ if h.signer != nil {
+ sigdata := chunkdata[cursor : cursor+signatureLength]
+ if len(sigdata) > 0 {
+ signature = &Signature{}
+ copy(signature[:], sigdata)
+ }
+ }
+
+ return signature, period, version, name, data, ismultihash, nil
+}
+
+// Adds an actual data update
+//
+// Uses the data currently loaded in the resources map entry.
+// It is the caller's responsibility to make sure that this data is not stale.
+//
+// A resource update cannot span chunks, and thus has max length 4096
+func (h *Handler) UpdateMultihash(ctx context.Context, name string, data []byte) (storage.Address, error) {
+ // \TODO perhaps this check should be in newUpdateChunk()
+ if _, _, err := multihash.GetMultihashLength(data); err != nil {
+ return nil, NewError(ErrNothingToReturn, err.Error())
+ }
+ return h.update(ctx, name, data, true)
+}
+
+func (h *Handler) Update(ctx context.Context, name string, data []byte) (storage.Address, error) {
+ return h.update(ctx, name, data, false)
+}
+
+// create and commit an update
+func (h *Handler) update(ctx context.Context, name string, data []byte, multihash bool) (storage.Address, error) {
+
+ // zero-length updates are bogus
+ if len(data) == 0 {
+ return nil, NewError(ErrInvalidValue, "I refuse to waste swarm space for updates with empty values, amigo (data length is 0)")
+ }
+
+ // we can't update anything without a store
+ if h.chunkStore == nil {
+ return nil, NewError(ErrInit, "Call Handler.SetStore() before updating")
+ }
+
+ // signature length is 0 if we are not using them
+ var signaturelength int
+ if h.signer != nil {
+ signaturelength = signatureLength
+ }
+
+ // get the cached information
+ nameHash := ens.EnsNode(name)
+ nameHashHex := nameHash.Hex()
+ rsrc := h.get(nameHashHex)
+ if rsrc == nil {
+ return nil, NewError(ErrNotFound, fmt.Sprintf(" object '%s' not in index", name))
+ } else if !rsrc.isSynced() {
+ return nil, NewError(ErrNotSynced, " object not in sync")
+ }
+
+ // an update can be only one chunk long; data length less header and signature data
+ // 12 = length of header and data length fields (2xuint16) plus period and frequency value fields (2xuint32)
+ datalimit := h.chunkSize() - int64(signaturelength-len(name)-12)
+ if int64(len(data)) > datalimit {
+ return nil, NewError(ErrDataOverflow, fmt.Sprintf("Data overflow: %d / %d bytes", len(data), datalimit))
+ }
+
+ // get our blockheight at this time and the next block of the update period
+ currentblock, err := h.getBlock(ctx, name)
+ if err != nil {
+ return nil, NewError(ErrIO, fmt.Sprintf("Could not get block height: %v", err))
+ }
+ nextperiod, err := getNextPeriod(rsrc.startBlock, currentblock, rsrc.frequency)
+ if err != nil {
+ return nil, err
+ }
+
+ // if we already have an update for this block then increment version
+ // resource object MUST be in sync for version to be correct, but we checked this earlier in the method already
+ var version uint32
+ if h.hasUpdate(nameHashHex, nextperiod) {
+ version = rsrc.version
+ }
+ version++
+
+ // calculate the chunk key
+ key := h.resourceHash(nextperiod, version, rsrc.nameHash)
+
+ // if we have a signing function, sign the update
+ // \TODO this code should probably be consolidated with corresponding code in New()
+ var signature *Signature
+ if h.signer != nil {
+ // sign the data hash with the key
+ digest := h.keyDataHash(key, data)
+ sig, err := h.signer.Sign(digest)
+ if err != nil {
+ return nil, NewError(ErrInvalidSignature, fmt.Sprintf("Sign fail: %v", err))
+ }
+ signature = &sig
+
+ // get the address of the signer (which also checks that it's a valid signature)
+ addr, err := getAddressFromDataSig(digest, *signature)
+ if err != nil {
+ return nil, NewError(ErrInvalidSignature, fmt.Sprintf("Invalid data/signature: %v", err))
+ }
+ if h.signer != nil {
+ // check if the signer has access to update
+ ok, err := h.checkAccess(name, addr)
+ if err != nil {
+ return nil, NewError(ErrIO, fmt.Sprintf("Access check fail: %v", err))
+ } else if !ok {
+ return nil, NewError(ErrUnauthorized, fmt.Sprintf("Address %x does not have access to update %s", addr, name))
+ }
+ }
+ }
+
+ // a datalength field set to 0 means the content is a multihash
+ var datalength int
+ if !multihash {
+ datalength = len(data)
+ }
+ chunk := newUpdateChunk(key, signature, nextperiod, version, name, data, datalength)
+
+ // send the chunk
+ h.chunkStore.Put(chunk)
+ log.Trace("resource update", "name", name, "key", key, "currentblock", currentblock, "lastperiod", nextperiod, "version", version, "data", chunk.SData, "multihash", multihash)
+
+ // update our resources map entry and return the new key
+ rsrc.lastPeriod = nextperiod
+ rsrc.version = version
+ rsrc.data = make([]byte, len(data))
+ copy(rsrc.data, data)
+ return key, nil
+}
+
+// Closes the datastore.
+// Always call this at shutdown to avoid data corruption.
+func (h *Handler) Close() {
+ h.chunkStore.Close()
+}
+
+// gets the current block height
+func (h *Handler) getBlock(ctx context.Context, name string) (uint64, error) {
+ blockheader, err := h.headerGetter.HeaderByNumber(ctx, name, nil)
+ if err != nil {
+ return 0, err
+ }
+ return blockheader.Number.Uint64(), nil
+}
+
+// Calculate the period index (aka major version number) from a given block number
+func (h *Handler) BlockToPeriod(name string, blocknumber uint64) (uint32, error) {
+ return getNextPeriod(h.resources[name].startBlock, blocknumber, h.resources[name].frequency)
+}
+
+// Calculate the block number from a given period index (aka major version number)
+func (h *Handler) PeriodToBlock(name string, period uint32) uint64 {
+ return h.resources[name].startBlock + (uint64(period) * h.resources[name].frequency)
+}
+
+// Retrieves the resource index value for the given nameHash
+func (h *Handler) get(nameHash string) *resource {
+ h.resourceLock.RLock()
+ defer h.resourceLock.RUnlock()
+ rsrc := h.resources[nameHash]
+ return rsrc
+}
+
+// Sets the resource index value for the given nameHash
+func (h *Handler) set(nameHash string, rsrc *resource) {
+ h.resourceLock.Lock()
+ defer h.resourceLock.Unlock()
+ h.resources[nameHash] = rsrc
+}
+
+// used for chunk keys
+func (h *Handler) resourceHash(period uint32, version uint32, namehash common.Hash) storage.Address {
+ // format is: hash(period|version|namehash)
+ hasher := h.hashPool.Get().(storage.SwarmHash)
+ defer h.hashPool.Put(hasher)
+ hasher.Reset()
+ b := make([]byte, 4)
+ binary.LittleEndian.PutUint32(b, period)
+ hasher.Write(b)
+ binary.LittleEndian.PutUint32(b, version)
+ hasher.Write(b)
+ hasher.Write(namehash[:])
+ return hasher.Sum(nil)
+}
+
+// Checks if we already have an update on this resource, according to the value in the current state of the resource index
+func (h *Handler) hasUpdate(nameHash string, period uint32) bool {
+ return h.resources[nameHash].lastPeriod == period
+}
+
+func getAddressFromDataSig(datahash common.Hash, signature Signature) (common.Address, error) {
+ pub, err := crypto.SigToPub(datahash.Bytes(), signature[:])
+ if err != nil {
+ return common.Address{}, err
+ }
+ return crypto.PubkeyToAddress(*pub), nil
+}
+
+// create an update chunk
+func newUpdateChunk(addr storage.Address, signature *Signature, period uint32, version uint32, name string, data []byte, datalength int) *storage.Chunk {
+
+ // no signatures if no validator
+ var signaturelength int
+ if signature != nil {
+ signaturelength = signatureLength
+ }
+
+ // prepend version and period to allow reverse lookups
+ headerlength := len(name) + 4 + 4
+
+ actualdatalength := len(data)
+ chunk := storage.NewChunk(addr, nil)
+ chunk.SData = make([]byte, 4+signaturelength+headerlength+actualdatalength) // initial 4 are uint16 length descriptors for headerlength and datalength
+
+ // data header length does NOT include the header length prefix bytes themselves
+ cursor := 0
+ binary.LittleEndian.PutUint16(chunk.SData[cursor:], uint16(headerlength))
+ cursor += 2
+
+ // data length
+ binary.LittleEndian.PutUint16(chunk.SData[cursor:], uint16(datalength))
+ cursor += 2
+
+ // header = period + version + name
+ binary.LittleEndian.PutUint32(chunk.SData[cursor:], period)
+ cursor += 4
+
+ binary.LittleEndian.PutUint32(chunk.SData[cursor:], version)
+ cursor += 4
+
+ namebytes := []byte(name)
+ copy(chunk.SData[cursor:], namebytes)
+ cursor += len(namebytes)
+
+ // add the data
+ copy(chunk.SData[cursor:], data)
+
+ // if signature is present it's the last item in the chunk data
+ if signature != nil {
+ cursor += actualdatalength
+ copy(chunk.SData[cursor:], signature[:])
+ }
+
+ chunk.Size = int64(len(chunk.SData))
+ return chunk
+}
+
+// Helper function to calculate the next update period number from the current block, start block and frequency
+func getNextPeriod(start uint64, current uint64, frequency uint64) (uint32, error) {
+ if current < start {
+ return 0, NewError(ErrInvalidValue, fmt.Sprintf("given current block value %d < start block %d", current, start))
+ }
+ blockdiff := current - start
+ period := blockdiff / frequency
+ return uint32(period + 1), nil
+}
+
+// ToSafeName is a helper function to create an valid idna of a given resource update name
+func ToSafeName(name string) (string, error) {
+ return idna.ToASCII(name)
+}
+
+// check that name identifiers contain valid bytes
+// Strings created using ToSafeName() should satisfy this check
+func isSafeName(name string) bool {
+ if name == "" {
+ return false
+ }
+ validname, err := idna.ToASCII(name)
+ if err != nil {
+ return false
+ }
+ return validname == name
+}
+
+func NewTestHandler(datadir string, params *HandlerParams) (*Handler, error) {
+ path := filepath.Join(datadir, DbDirName)
+ rh, err := NewHandler(params)
+ if err != nil {
+ return nil, fmt.Errorf("resource handler create fail: %v", err)
+ }
+ localstoreparams := storage.NewDefaultLocalStoreParams()
+ localstoreparams.Init(path)
+ localStore, err := storage.NewLocalStore(localstoreparams, nil)
+ if err != nil {
+ return nil, fmt.Errorf("localstore create fail, path %s: %v", path, err)
+ }
+ localStore.Validators = append(localStore.Validators, storage.NewContentAddressValidator(storage.MakeHashFunc(resourceHash)))
+ localStore.Validators = append(localStore.Validators, rh)
+ netStore := storage.NewNetStore(localStore, nil)
+ rh.SetStore(netStore)
+ return rh, nil
+}
generated by cgit (git 2.34.1) at 2024-11-14 05:18:36 +0800