storj/satellite/audit/verifier.go
2019-08-21 19:30:29 +03:00

701 lines
24 KiB
Go

// Copyright (C) 2019 Storj Labs, Inc.
// See LICENSE for copying information.
package audit
import (
"bytes"
"context"
"io"
"time"
"github.com/vivint/infectious"
"github.com/zeebo/errs"
"go.uber.org/zap"
"google.golang.org/grpc/codes"
monkit "gopkg.in/spacemonkeygo/monkit.v2"
"storj.io/storj/internal/errs2"
"storj.io/storj/internal/memory"
"storj.io/storj/pkg/identity"
"storj.io/storj/pkg/pb"
"storj.io/storj/pkg/pkcrypto"
"storj.io/storj/pkg/storj"
"storj.io/storj/pkg/transport"
"storj.io/storj/satellite/metainfo"
"storj.io/storj/satellite/orders"
"storj.io/storj/satellite/overlay"
"storj.io/storj/storage"
"storj.io/storj/uplink/piecestore"
)
var (
mon = monkit.Package()
// ErrNotEnoughShares is the errs class for when not enough shares are available to do an audit
ErrNotEnoughShares = errs.Class("not enough shares for successful audit")
// ErrSegmentDeleted is the errs class when the audited segment was deleted during the audit
ErrSegmentDeleted = errs.Class("segment deleted during audit")
)
// Share represents required information about an audited share
type Share struct {
Error error
PieceNum int
NodeID storj.NodeID
Data []byte
}
// Verifier helps verify the correctness of a given stripe
type Verifier struct {
log *zap.Logger
metainfo *metainfo.Service
orders *orders.Service
auditor *identity.PeerIdentity
transport transport.Client
overlay *overlay.Service
containment Containment
minBytesPerSecond memory.Size
minDownloadTimeout time.Duration
}
// NewVerifier creates a Verifier
func NewVerifier(log *zap.Logger, metainfo *metainfo.Service, transport transport.Client, overlay *overlay.Service, containment Containment, orders *orders.Service, id *identity.FullIdentity, minBytesPerSecond memory.Size, minDownloadTimeout time.Duration) *Verifier {
return &Verifier{
log: log,
metainfo: metainfo,
orders: orders,
auditor: id.PeerIdentity(),
transport: transport,
overlay: overlay,
containment: containment,
minBytesPerSecond: minBytesPerSecond,
minDownloadTimeout: minDownloadTimeout,
}
}
// Verify downloads shares then verifies the data correctness at the given stripe
func (verifier *Verifier) Verify(ctx context.Context, stripe *Stripe, skip map[storj.NodeID]bool) (report *Report, err error) {
defer mon.Task()(&ctx)(&err)
pointer := stripe.Segment
shareSize := pointer.GetRemote().GetRedundancy().GetErasureShareSize()
bucketID := createBucketID(stripe.SegmentPath)
var offlineNodes storj.NodeIDList
var failedNodes storj.NodeIDList
containedNodes := make(map[int]storj.NodeID)
sharesToAudit := make(map[int]Share)
orderLimits, privateKey, err := verifier.orders.CreateAuditOrderLimits(ctx, bucketID, pointer, skip)
if err != nil {
return nil, err
}
// NOTE offlineNodes will include disqualified nodes because they aren't in
// the skip list
offlineNodes = getOfflineNodes(stripe.Segment, orderLimits, skip)
if len(offlineNodes) > 0 {
verifier.log.Debug("Verify: order limits not created for some nodes (offline/disqualified)", zap.Strings("Node IDs", offlineNodes.Strings()))
}
shares, err := verifier.DownloadShares(ctx, orderLimits, privateKey, stripe.Index, shareSize)
if err != nil {
return &Report{
Offlines: offlineNodes,
}, err
}
_, err = verifier.checkIfSegmentDeleted(ctx, stripe.SegmentPath, stripe.Segment)
if err != nil {
return &Report{
Offlines: offlineNodes,
}, err
}
for pieceNum, share := range shares {
if share.Error == nil {
// no error -- share downloaded successfully
sharesToAudit[pieceNum] = share
continue
}
if transport.Error.Has(share.Error) {
if errs.Is(share.Error, context.DeadlineExceeded) {
// dial timeout
offlineNodes = append(offlineNodes, share.NodeID)
verifier.log.Debug("Verify: dial timeout (offline)", zap.Stringer("Node ID", share.NodeID), zap.Error(share.Error))
continue
}
if errs2.IsRPC(share.Error, codes.Unknown) {
// dial failed -- offline node
offlineNodes = append(offlineNodes, share.NodeID)
verifier.log.Debug("Verify: dial failed (offline)", zap.Stringer("Node ID", share.NodeID), zap.Error(share.Error))
continue
}
// unknown transport error
containedNodes[pieceNum] = share.NodeID
verifier.log.Debug("Verify: unknown transport error (contained)", zap.Stringer("Node ID", share.NodeID), zap.Error(share.Error))
}
if errs2.IsRPC(share.Error, codes.NotFound) {
// missing share
failedNodes = append(failedNodes, share.NodeID)
verifier.log.Debug("Verify: piece not found (audit failed)", zap.Stringer("Node ID", share.NodeID), zap.Error(share.Error))
continue
}
if errs2.IsRPC(share.Error, codes.DeadlineExceeded) {
// dial successful, but download timed out
containedNodes[pieceNum] = share.NodeID
verifier.log.Debug("Verify: download timeout (contained)", zap.Stringer("Node ID", share.NodeID), zap.Error(share.Error))
continue
}
// unknown error
containedNodes[pieceNum] = share.NodeID
verifier.log.Debug("Verify: unknown error (contained)", zap.Stringer("Node ID", share.NodeID), zap.Error(share.Error))
}
required := int(pointer.Remote.Redundancy.GetMinReq())
total := int(pointer.Remote.Redundancy.GetTotal())
if len(sharesToAudit) < required {
return &Report{
Fails: failedNodes,
Offlines: offlineNodes,
}, ErrNotEnoughShares.New("got %d, required %d", len(sharesToAudit), required)
}
pieceNums, correctedShares, err := auditShares(ctx, required, total, sharesToAudit)
if err != nil {
return &Report{
Fails: failedNodes,
Offlines: offlineNodes,
}, err
}
for _, pieceNum := range pieceNums {
failedNodes = append(failedNodes, shares[pieceNum].NodeID)
}
// remove failed audit pieces from the pointer so as to only penalize once for failed audits
err = verifier.removeFailedPieces(ctx, stripe.SegmentPath, stripe.Segment, failedNodes)
if err != nil {
verifier.log.Warn("Verify: failed to delete failed pieces", zap.Error(err))
}
successNodes := getSuccessNodes(ctx, shares, failedNodes, offlineNodes, containedNodes)
totalInPointer := len(stripe.Segment.GetRemote().GetRemotePieces())
numOffline := len(offlineNodes)
numSuccessful := len(successNodes)
numFailed := len(failedNodes)
numContained := len(containedNodes)
totalAudited := numSuccessful + numFailed + numOffline + numContained
auditedPercentage := float64(totalAudited) / float64(totalInPointer)
offlinePercentage := float64(0)
successfulPercentage := float64(0)
failedPercentage := float64(0)
containedPercentage := float64(0)
if totalAudited > 0 {
offlinePercentage = float64(numOffline) / float64(totalAudited)
successfulPercentage = float64(numSuccessful) / float64(totalAudited)
failedPercentage = float64(numFailed) / float64(totalAudited)
containedPercentage = float64(numContained) / float64(totalAudited)
}
mon.Meter("audit_success_nodes_global").Mark(numSuccessful)
mon.Meter("audit_fail_nodes_global").Mark(numFailed)
mon.Meter("audit_offline_nodes_global").Mark(numOffline)
mon.Meter("audit_contained_nodes_global").Mark(numContained)
mon.Meter("audit_total_nodes_global").Mark(totalAudited)
mon.Meter("audit_total_pointer_nodes_global").Mark(totalInPointer)
mon.IntVal("audit_success_nodes").Observe(int64(numSuccessful))
mon.IntVal("audit_fail_nodes").Observe(int64(numFailed))
mon.IntVal("audit_offline_nodes").Observe(int64(numOffline))
mon.IntVal("audit_contained_nodes").Observe(int64(numContained))
mon.IntVal("audit_total_nodes").Observe(int64(totalAudited))
mon.IntVal("audit_total_pointer_nodes").Observe(int64(totalInPointer))
mon.FloatVal("audited_percentage").Observe(auditedPercentage)
mon.FloatVal("audit_offline_percentage").Observe(offlinePercentage)
mon.FloatVal("audit_successful_percentage").Observe(successfulPercentage)
mon.FloatVal("audit_failed_percentage").Observe(failedPercentage)
mon.FloatVal("audit_contained_percentage").Observe(containedPercentage)
pendingAudits, err := createPendingAudits(ctx, containedNodes, correctedShares, stripe)
if err != nil {
return &Report{
Successes: successNodes,
Fails: failedNodes,
Offlines: offlineNodes,
}, err
}
return &Report{
Successes: successNodes,
Fails: failedNodes,
Offlines: offlineNodes,
PendingAudits: pendingAudits,
}, nil
}
// DownloadShares downloads shares from the nodes where remote pieces are located
func (verifier *Verifier) DownloadShares(ctx context.Context, limits []*pb.AddressedOrderLimit, piecePrivateKey storj.PiecePrivateKey, stripeIndex int64, shareSize int32) (shares map[int]Share, err error) {
defer mon.Task()(&ctx)(&err)
shares = make(map[int]Share, len(limits))
ch := make(chan *Share, len(limits))
for i, limit := range limits {
if limit == nil {
ch <- nil
continue
}
go func(i int, limit *pb.AddressedOrderLimit) {
share, err := verifier.GetShare(ctx, limit, piecePrivateKey, stripeIndex, shareSize, i)
if err != nil {
share = Share{
Error: err,
PieceNum: i,
NodeID: limit.GetLimit().StorageNodeId,
Data: nil,
}
}
ch <- &share
}(i, limit)
}
for range limits {
share := <-ch
if share != nil {
shares[share.PieceNum] = *share
}
}
return shares, nil
}
// Reverify reverifies the contained nodes in the stripe
func (verifier *Verifier) Reverify(ctx context.Context, stripe *Stripe) (report *Report, err error) {
defer mon.Task()(&ctx)(&err)
// result status enum
const (
skipped = iota
success
offline
failed
contained
erred
)
type result struct {
nodeID storj.NodeID
status int
pendingAudit *PendingAudit
err error
}
pieces := stripe.Segment.GetRemote().GetRemotePieces()
ch := make(chan result, len(pieces))
var containedInSegment int64
for _, piece := range pieces {
pending, err := verifier.containment.Get(ctx, piece.NodeId)
if err != nil {
if ErrContainedNotFound.Has(err) {
ch <- result{nodeID: piece.NodeId, status: skipped}
continue
}
ch <- result{nodeID: piece.NodeId, status: erred, err: err}
verifier.log.Debug("Reverify: error getting from containment db", zap.Stringer("Node ID", piece.NodeId), zap.Error(err))
continue
}
containedInSegment++
go func(pending *PendingAudit, piece *pb.RemotePiece) {
limit, piecePrivateKey, err := verifier.orders.CreateAuditOrderLimit(ctx, createBucketID(stripe.SegmentPath), pending.NodeID, piece.PieceNum, pending.PieceID, pending.ShareSize)
if err != nil {
if overlay.ErrNodeDisqualified.Has(err) {
_, errDelete := verifier.containment.Delete(ctx, piece.NodeId)
if errDelete != nil {
verifier.log.Debug("Error deleting disqualified node from containment db", zap.Stringer("Node ID", piece.NodeId), zap.Error(err))
err = errs.Combine(err, errDelete)
}
ch <- result{nodeID: piece.NodeId, status: erred, err: err}
verifier.log.Debug("Reverify: order limit not created (disqualified)", zap.Stringer("Node ID", piece.NodeId))
return
}
if overlay.ErrNodeOffline.Has(err) {
ch <- result{nodeID: piece.NodeId, status: offline}
verifier.log.Debug("Reverify: order limit not created (offline)", zap.Stringer("Node ID", piece.NodeId))
return
}
ch <- result{nodeID: piece.NodeId, status: erred, err: err}
verifier.log.Debug("Reverify: error creating order limit", zap.Stringer("Node ID", piece.NodeId), zap.Error(err))
return
}
share, err := verifier.GetShare(ctx, limit, piecePrivateKey, pending.StripeIndex, pending.ShareSize, int(piece.PieceNum))
// check if the pending audit was deleted while downloading the share
_, getErr := verifier.containment.Get(ctx, piece.NodeId)
if getErr != nil {
if ErrContainedNotFound.Has(getErr) {
ch <- result{nodeID: piece.NodeId, status: skipped}
verifier.log.Debug("Reverify: pending audit deleted during reverification", zap.Stringer("Node ID", piece.NodeId), zap.Error(getErr))
return
}
ch <- result{nodeID: piece.NodeId, status: erred, err: getErr}
verifier.log.Debug("Reverify: error getting from containment db", zap.Stringer("Node ID", piece.NodeId), zap.Error(getErr))
return
}
// analyze the error from GetShare
if err != nil {
if transport.Error.Has(err) {
if errs.Is(err, context.DeadlineExceeded) {
// dial timeout
ch <- result{nodeID: piece.NodeId, status: offline}
verifier.log.Debug("Reverify: dial timeout (offline)", zap.Stringer("Node ID", piece.NodeId), zap.Error(err))
return
}
if errs2.IsRPC(err, codes.Unknown) {
// dial failed -- offline node
verifier.log.Debug("Reverify: dial failed (offline)", zap.Stringer("Node ID", piece.NodeId), zap.Error(err))
ch <- result{nodeID: piece.NodeId, status: offline}
return
}
// unknown transport error
ch <- result{nodeID: piece.NodeId, status: contained, pendingAudit: pending}
verifier.log.Debug("Reverify: unknown transport error (contained)", zap.Stringer("Node ID", piece.NodeId), zap.Error(err))
return
}
if errs2.IsRPC(err, codes.NotFound) {
// Get the original segment pointer in the metainfo
oldPtr, err := verifier.checkIfSegmentDeleted(ctx, pending.Path, stripe.Segment)
if err != nil {
ch <- result{nodeID: piece.NodeId, status: success}
verifier.log.Debug("Reverify: audit source deleted before reverification", zap.Stringer("Node ID", piece.NodeId), zap.Error(err))
return
}
// remove failed audit pieces from the pointer so as to only penalize once for failed audits
err = verifier.removeFailedPieces(ctx, pending.Path, oldPtr, storj.NodeIDList{pending.NodeID})
if err != nil {
verifier.log.Warn("Reverify: failed to delete failed pieces", zap.Stringer("Node ID", piece.NodeId), zap.Error(err))
}
// missing share
ch <- result{nodeID: piece.NodeId, status: failed}
verifier.log.Debug("Reverify: piece not found (audit failed)", zap.Stringer("Node ID", piece.NodeId), zap.Error(err))
return
}
if errs2.IsRPC(err, codes.DeadlineExceeded) {
// dial successful, but download timed out
ch <- result{nodeID: piece.NodeId, status: contained, pendingAudit: pending}
verifier.log.Debug("Reverify: download timeout (contained)", zap.Stringer("Node ID", piece.NodeId), zap.Error(err))
return
}
// unknown error
ch <- result{nodeID: piece.NodeId, status: contained, pendingAudit: pending}
verifier.log.Debug("Reverify: unknown error (contained)", zap.Stringer("Node ID", piece.NodeId), zap.Error(err))
return
}
downloadedHash := pkcrypto.SHA256Hash(share.Data)
if bytes.Equal(downloadedHash, pending.ExpectedShareHash) {
ch <- result{nodeID: piece.NodeId, status: success}
verifier.log.Debug("Reverify: hashes match (audit success)", zap.Stringer("Node ID", piece.NodeId))
} else {
oldPtr, err := verifier.checkIfSegmentDeleted(ctx, pending.Path, nil)
if err != nil {
ch <- result{nodeID: piece.NodeId, status: success}
verifier.log.Debug("Reverify: audit source deleted before reverification", zap.Stringer("Node ID", piece.NodeId), zap.Error(err))
return
}
// remove failed audit pieces from the pointer so as to only penalize once for failed audits
err = verifier.removeFailedPieces(ctx, pending.Path, oldPtr, storj.NodeIDList{pending.NodeID})
if err != nil {
verifier.log.Warn("Reverify: failed to delete failed pieces", zap.Stringer("Node ID", piece.NodeId), zap.Error(err))
}
verifier.log.Debug("Reverify: hashes mismatch (audit failed)", zap.Stringer("Node ID", piece.NodeId),
zap.Binary("expected hash", pending.ExpectedShareHash), zap.Binary("downloaded hash", downloadedHash))
ch <- result{nodeID: piece.NodeId, status: failed}
}
}(pending, piece)
}
report = &Report{}
for range pieces {
result := <-ch
switch result.status {
case success:
report.Successes = append(report.Successes, result.nodeID)
case offline:
report.Offlines = append(report.Offlines, result.nodeID)
case failed:
report.Fails = append(report.Fails, result.nodeID)
case contained:
report.PendingAudits = append(report.PendingAudits, result.pendingAudit)
case erred:
err = errs.Combine(err, result.err)
}
}
mon.Meter("reverify_successes_global").Mark(len(report.Successes))
mon.Meter("reverify_offlines_global").Mark(len(report.Offlines))
mon.Meter("reverify_fails_global").Mark(len(report.Fails))
mon.Meter("reverify_contained_global").Mark(len(report.PendingAudits))
mon.IntVal("reverify_successes").Observe(int64(len(report.Successes)))
mon.IntVal("reverify_offlines").Observe(int64(len(report.Offlines)))
mon.IntVal("reverify_fails").Observe(int64(len(report.Fails)))
mon.IntVal("reverify_contained").Observe(int64(len(report.PendingAudits)))
mon.IntVal("reverify_contained_in_segment").Observe(containedInSegment)
mon.IntVal("reverify_total_in_segment").Observe(int64(len(pieces)))
return report, err
}
// GetShare use piece store client to download shares from nodes
func (verifier *Verifier) GetShare(ctx context.Context, limit *pb.AddressedOrderLimit, piecePrivateKey storj.PiecePrivateKey, stripeIndex int64, shareSize int32, pieceNum int) (share Share, err error) {
defer mon.Task()(&ctx)(&err)
bandwidthMsgSize := shareSize
// determines number of seconds allotted for receiving data from a storage node
timedCtx := ctx
if verifier.minBytesPerSecond > 0 {
maxTransferTime := time.Duration(int64(time.Second) * int64(bandwidthMsgSize) / verifier.minBytesPerSecond.Int64())
if maxTransferTime < verifier.minDownloadTimeout {
maxTransferTime = verifier.minDownloadTimeout
}
var cancel func()
timedCtx, cancel = context.WithTimeout(ctx, maxTransferTime)
defer cancel()
}
storageNodeID := limit.GetLimit().StorageNodeId
log := verifier.log.Named(storageNodeID.String())
target := &pb.Node{Id: storageNodeID, Address: limit.GetStorageNodeAddress()}
ps, err := piecestore.Dial(timedCtx, verifier.transport, target, log, piecestore.DefaultConfig)
if err != nil {
return Share{}, Error.Wrap(err)
}
defer func() {
err := ps.Close()
if err != nil {
verifier.log.Error("audit verifier failed to close conn to node: %+v", zap.Error(err))
}
}()
offset := int64(shareSize) * stripeIndex
downloader, err := ps.Download(timedCtx, limit.GetLimit(), piecePrivateKey, offset, int64(shareSize))
if err != nil {
return Share{}, err
}
defer func() { err = errs.Combine(err, downloader.Close()) }()
buf := make([]byte, shareSize)
_, err = io.ReadFull(downloader, buf)
if err != nil {
return Share{}, err
}
return Share{
Error: nil,
PieceNum: pieceNum,
NodeID: storageNodeID,
Data: buf,
}, nil
}
// removeFailedPieces removes lost pieces from a pointer
func (verifier *Verifier) removeFailedPieces(ctx context.Context, path string, pointer *pb.Pointer, failedNodes storj.NodeIDList) (err error) {
defer mon.Task()(&ctx)(&err)
if len(failedNodes) == 0 {
return nil
}
var toRemove []*pb.RemotePiece
OUTER:
for _, piece := range pointer.GetRemote().GetRemotePieces() {
for _, failedNode := range failedNodes {
if piece.NodeId == failedNode {
toRemove = append(toRemove, piece)
continue OUTER
}
}
}
// Update the segment pointer in the metainfo
_, err = verifier.metainfo.UpdatePieces(ctx, path, pointer, nil, toRemove)
return err
}
// checkIfSegmentDeleted checks if stripe's pointer has been deleted since stripe was selected.
func (verifier *Verifier) checkIfSegmentDeleted(ctx context.Context, segmentPath string, oldPointer *pb.Pointer) (newPointer *pb.Pointer, err error) {
defer mon.Task()(&ctx)(&err)
newPointer, err = verifier.metainfo.Get(ctx, segmentPath)
if err != nil {
if storage.ErrKeyNotFound.Has(err) {
return nil, ErrSegmentDeleted.New("%q", segmentPath)
}
return nil, err
}
if oldPointer != nil && oldPointer.CreationDate != newPointer.CreationDate {
return nil, ErrSegmentDeleted.New("%q", segmentPath)
}
return newPointer, nil
}
// auditShares takes the downloaded shares and uses infectious's Correct function to check that they
// haven't been altered. auditShares returns a slice containing the piece numbers of altered shares,
// and a slice of the corrected shares.
func auditShares(ctx context.Context, required, total int, originals map[int]Share) (pieceNums []int, corrected []infectious.Share, err error) {
defer mon.Task()(&ctx)(&err)
f, err := infectious.NewFEC(required, total)
if err != nil {
return nil, nil, err
}
copies, err := makeCopies(ctx, originals)
if err != nil {
return nil, nil, err
}
err = f.Correct(copies)
if err != nil {
return nil, nil, err
}
for _, share := range copies {
if !bytes.Equal(originals[share.Number].Data, share.Data) {
pieceNums = append(pieceNums, share.Number)
}
}
return pieceNums, copies, nil
}
// makeCopies takes in a map of audit Shares and deep copies their data to a slice of infectious Shares
func makeCopies(ctx context.Context, originals map[int]Share) (copies []infectious.Share, err error) {
defer mon.Task()(&ctx)(&err)
copies = make([]infectious.Share, 0, len(originals))
for _, original := range originals {
copies = append(copies, infectious.Share{
Data: append([]byte{}, original.Data...),
Number: original.PieceNum})
}
return copies, nil
}
// getOfflines nodes returns these storage nodes from pointer which have no
// order limit nor are skipped.
func getOfflineNodes(pointer *pb.Pointer, limits []*pb.AddressedOrderLimit, skip map[storj.NodeID]bool) storj.NodeIDList {
var offlines storj.NodeIDList
nodesWithLimit := make(map[storj.NodeID]bool, len(limits))
for _, limit := range limits {
if limit != nil {
nodesWithLimit[limit.GetLimit().StorageNodeId] = true
}
}
for _, piece := range pointer.GetRemote().GetRemotePieces() {
if !nodesWithLimit[piece.NodeId] && !skip[piece.NodeId] {
offlines = append(offlines, piece.NodeId)
}
}
return offlines
}
// getSuccessNodes uses the failed nodes, offline nodes and contained nodes arrays to determine which nodes passed the audit
func getSuccessNodes(ctx context.Context, shares map[int]Share, failedNodes, offlineNodes storj.NodeIDList, containedNodes map[int]storj.NodeID) (successNodes storj.NodeIDList) {
defer mon.Task()(&ctx)(nil)
fails := make(map[storj.NodeID]bool)
for _, fail := range failedNodes {
fails[fail] = true
}
for _, offline := range offlineNodes {
fails[offline] = true
}
for _, contained := range containedNodes {
fails[contained] = true
}
for _, share := range shares {
if !fails[share.NodeID] {
successNodes = append(successNodes, share.NodeID)
}
}
return successNodes
}
func createBucketID(path storj.Path) []byte {
comps := storj.SplitPath(path)
if len(comps) < 3 {
return nil
}
// project_id/bucket_name
return []byte(storj.JoinPaths(comps[0], comps[2]))
}
func createPendingAudits(ctx context.Context, containedNodes map[int]storj.NodeID, correctedShares []infectious.Share, stripe *Stripe) (pending []*PendingAudit, err error) {
defer mon.Task()(&ctx)(&err)
if len(containedNodes) == 0 {
return nil, nil
}
redundancy := stripe.Segment.GetRemote().GetRedundancy()
required := int(redundancy.GetMinReq())
total := int(redundancy.GetTotal())
shareSize := redundancy.GetErasureShareSize()
fec, err := infectious.NewFEC(required, total)
if err != nil {
return nil, Error.Wrap(err)
}
stripeData, err := rebuildStripe(ctx, fec, correctedShares, int(shareSize))
if err != nil {
return nil, Error.Wrap(err)
}
for pieceNum, nodeID := range containedNodes {
share := make([]byte, shareSize)
err = fec.EncodeSingle(stripeData, share, pieceNum)
if err != nil {
return nil, Error.Wrap(err)
}
pending = append(pending, &PendingAudit{
NodeID: nodeID,
PieceID: stripe.Segment.GetRemote().RootPieceId,
StripeIndex: stripe.Index,
ShareSize: shareSize,
ExpectedShareHash: pkcrypto.SHA256Hash(share),
Path: stripe.SegmentPath,
})
}
return pending, nil
}
func rebuildStripe(ctx context.Context, fec *infectious.FEC, corrected []infectious.Share, shareSize int) (_ []byte, err error) {
defer mon.Task()(&ctx)(&err)
stripe := make([]byte, fec.Required()*shareSize)
err = fec.Rebuild(corrected, func(share infectious.Share) {
copy(stripe[share.Number*shareSize:], share.Data)
})
if err != nil {
return nil, err
}
return stripe, nil
}