// Close cleanly terminates the download loop with the host and closes the
// connection.
func (hd *Downloader) Close() error {
extendDeadline(hd.conn, modules.NegotiateSettingsTime)
// don't care about these errors
_, _ = verifySettings(hd.conn, hd.host)
_ = modules.WriteNegotiationStop(hd.conn)
return hd.conn.Close()
}
// TestNegotiateRevisionStopResponse tests that when the host sends
// StopResponse, the renter continues processing the revision instead of
// immediately terminating.
func TestNegotiateRevisionStopResponse(t *testing.T) {
// simulate a renter-host connection
rConn, hConn := net.Pipe()
// handle the host's half of the pipe
go func() {
defer hConn.Close()
// read revision
encoding.ReadObject(hConn, new(types.FileContractRevision), 1<<22)
// write acceptance
modules.WriteNegotiationAcceptance(hConn)
// read txn signature
encoding.ReadObject(hConn, new(types.TransactionSignature), 1<<22)
// write StopResponse
modules.WriteNegotiationStop(hConn)
// write txn signature
encoding.WriteObject(hConn, types.TransactionSignature{})
}()
// since the host wrote StopResponse, we should proceed to validating the
// transaction. This will return a known error because we are supplying an
// empty revision.
_, err := negotiateRevision(rConn, types.FileContractRevision{}, crypto.SecretKey{})
if err != types.ErrFileContractWindowStartViolation {
t.Fatalf("expected %q, got \"%v\"", types.ErrFileContractWindowStartViolation, err)
}
rConn.Close()
// same as above, but send an error instead of StopResponse. The error
// should be returned by negotiateRevision immediately (if it is not, we
// should expect to see a transaction validation error instead).
rConn, hConn = net.Pipe()
go func() {
defer hConn.Close()
encoding.ReadObject(hConn, new(types.FileContractRevision), 1<<22)
modules.WriteNegotiationAcceptance(hConn)
encoding.ReadObject(hConn, new(types.TransactionSignature), 1<<22)
// write a sentinel error
modules.WriteNegotiationRejection(hConn, errors.New("sentinel"))
encoding.WriteObject(hConn, types.TransactionSignature{})
}()
expectedErr := "host did not accept transaction signature: sentinel"
_, err = negotiateRevision(rConn, types.FileContractRevision{}, crypto.SecretKey{})
if err == nil || err.Error() != expectedErr {
t.Fatalf("expected %q, got \"%v\"", expectedErr, err)
}
rConn.Close()
}
// managedRevisionIteration handles one iteration of the revision loop. As a
// performance optimization, multiple iterations of revisions are allowed to be
// made over the same connection.
func (h *Host) managedRevisionIteration(conn net.Conn, so *storageObligation, finalIter bool) error {
// Send the settings to the renter. The host will keep going even if it is
// not accepting contracts, because in this case the contract already
// exists.
err := h.managedRPCSettings(conn)
if err != nil {
return err
}
// Set the negotiation deadline.
conn.SetDeadline(time.Now().Add(modules.NegotiateFileContractRevisionTime))
// The renter will either accept or reject the settings + revision
// transaction. It may also return a stop response to indicate that it
// wishes to terminate the revision loop.
err = modules.ReadNegotiationAcceptance(conn)
if err != nil {
return err
}
// Read some variables from the host for use later in the function.
h.mu.RLock()
settings := h.settings
secretKey := h.secretKey
blockHeight := h.blockHeight
h.mu.RUnlock()
// The renter is going to send its intended modifications, followed by the
// file contract revision that pays for them.
var modifications []modules.RevisionAction
var revision types.FileContractRevision
err = encoding.ReadObject(conn, &modifications, settings.MaxReviseBatchSize)
if err != nil {
return err
}
err = encoding.ReadObject(conn, &revision, modules.NegotiateMaxFileContractRevisionSize)
if err != nil {
return err
}
// First read all of the modifications. Then make the modifications, but
// with the ability to reverse them. Then verify the file contract revision
// correctly accounts for the changes.
var bandwidthRevenue types.Currency // Upload bandwidth.
var storageRevenue types.Currency
var newCollateral types.Currency
var sectorsRemoved []crypto.Hash
var sectorsGained []crypto.Hash
var gainedSectorData [][]byte
err = func() error {
for _, modification := range modifications {
// Check that the index points to an existing sector root. If the type
// is ActionInsert, we permit inserting at the end.
if modification.Type == modules.ActionInsert {
if modification.SectorIndex > uint64(len(so.SectorRoots)) {
return errBadModificationIndex
}
} else if modification.SectorIndex >= uint64(len(so.SectorRoots)) {
return errBadModificationIndex
}
// Check that the data sent for the sector is not too large.
if uint64(len(modification.Data)) > modules.SectorSize {
return errLargeSector
}
switch modification.Type {
case modules.ActionDelete:
// There is no financial information to change, it is enough to
// remove the sector.
sectorsRemoved = append(sectorsRemoved, so.SectorRoots[modification.SectorIndex])
so.SectorRoots = append(so.SectorRoots[0:modification.SectorIndex], so.SectorRoots[modification.SectorIndex+1:]...)
case modules.ActionInsert:
// Check that the sector size is correct.
if uint64(len(modification.Data)) != modules.SectorSize {
return errBadSectorSize
}
// Update finances.
blocksRemaining := so.proofDeadline() - blockHeight
blockBytesCurrency := types.NewCurrency64(uint64(blocksRemaining)).Mul64(modules.SectorSize)
bandwidthRevenue = bandwidthRevenue.Add(settings.MinUploadBandwidthPrice.Mul64(modules.SectorSize))
storageRevenue = storageRevenue.Add(settings.MinStoragePrice.Mul(blockBytesCurrency))
newCollateral = newCollateral.Add(settings.Collateral.Mul(blockBytesCurrency))
// Insert the sector into the root list.
newRoot := crypto.MerkleRoot(modification.Data)
sectorsGained = append(sectorsGained, newRoot)
gainedSectorData = append(gainedSectorData, modification.Data)
so.SectorRoots = append(so.SectorRoots[:modification.SectorIndex], append([]crypto.Hash{newRoot}, so.SectorRoots[modification.SectorIndex:]...)...)
case modules.ActionModify:
// Check that the offset and length are okay. Length is already
// known to be appropriately small, but the offset needs to be
// checked for being appropriately small as well otherwise there is
// a risk of overflow.
if modification.Offset > modules.SectorSize || modification.Offset+uint64(len(modification.Data)) > modules.SectorSize {
return errIllegalOffsetAndLength
}
// Get the data for the new sector.
sector, err := h.ReadSector(so.SectorRoots[modification.SectorIndex])
if err != nil {
return err
}
copy(sector[modification.Offset:], modification.Data)
// Update finances.
bandwidthRevenue = bandwidthRevenue.Add(settings.MinUploadBandwidthPrice.Mul64(uint64(len(modification.Data))))
// Update the sectors removed and gained to indicate that the old
// sector has been replaced with a new sector.
newRoot := crypto.MerkleRoot(sector)
sectorsRemoved = append(sectorsRemoved, so.SectorRoots[modification.SectorIndex])
sectorsGained = append(sectorsGained, newRoot)
gainedSectorData = append(gainedSectorData, sector)
so.SectorRoots[modification.SectorIndex] = newRoot
default:
return errUnknownModification
}
}
newRevenue := storageRevenue.Add(bandwidthRevenue)
return verifyRevision(so, revision, blockHeight, newRevenue, newCollateral)
}()
if err != nil {
return modules.WriteNegotiationRejection(conn, err)
}
// Revision is acceptable, write an acceptance string.
err = modules.WriteNegotiationAcceptance(conn)
if err != nil {
return err
}
// Renter will send a transaction signature for the file contract revision.
var renterSig types.TransactionSignature
err = encoding.ReadObject(conn, &renterSig, modules.NegotiateMaxTransactionSignatureSize)
if err != nil {
return err
}
// Verify that the signature is valid and get the host's signature.
txn, err := createRevisionSignature(revision, renterSig, secretKey, blockHeight)
if err != nil {
return modules.WriteNegotiationRejection(conn, err)
}
so.PotentialStorageRevenue = so.PotentialStorageRevenue.Add(storageRevenue)
so.RiskedCollateral = so.RiskedCollateral.Add(newCollateral)
so.PotentialUploadRevenue = so.PotentialUploadRevenue.Add(bandwidthRevenue)
so.RevisionTransactionSet = []types.Transaction{txn}
err = h.modifyStorageObligation(so, sectorsRemoved, sectorsGained, gainedSectorData)
if err != nil {
return modules.WriteNegotiationRejection(conn, err)
}
// Host will now send acceptance and its signature to the renter. This
// iteration is complete. If the finalIter flag is set, StopResponse will
// be sent instead. This indicates to the renter that the host wishes to
// terminate the revision loop.
if finalIter {
err = modules.WriteNegotiationStop(conn)
} else {
err = modules.WriteNegotiationAcceptance(conn)
}
if err != nil {
return err
}
return encoding.WriteObject(conn, txn.TransactionSignatures[1])
}