// managedFinalizeContract will take a file contract, add the host's
// collateral, and then try submitting the file contract to the transaction
// pool. If there is no error, the completed transaction set will be returned
// to the caller.
func (h *Host) managedFinalizeContract(builder modules.TransactionBuilder, renterPK crypto.PublicKey, renterSignatures []types.TransactionSignature, renterRevisionSignature types.TransactionSignature, initialSectorRoots []crypto.Hash, hostCollateral, hostInitialRevenue, hostInitialRisk types.Currency) ([]types.TransactionSignature, types.TransactionSignature, types.FileContractID, error) {
for _, sig := range renterSignatures {
builder.AddTransactionSignature(sig)
}
fullTxnSet, err := builder.Sign(true)
if err != nil {
builder.Drop()
return nil, types.TransactionSignature{}, types.FileContractID{}, err
}
// Verify that the signature for the revision from the renter is correct.
h.mu.RLock()
blockHeight := h.blockHeight
hostSPK := h.publicKey
hostSK := h.secretKey
h.mu.RUnlock()
contractTxn := fullTxnSet[len(fullTxnSet)-1]
fc := contractTxn.FileContracts[0]
noOpRevision := types.FileContractRevision{
ParentID: contractTxn.FileContractID(0),
UnlockConditions: types.UnlockConditions{
PublicKeys: []types.SiaPublicKey{
{
Algorithm: types.SignatureEd25519,
Key: renterPK[:],
},
hostSPK,
},
SignaturesRequired: 2,
},
NewRevisionNumber: fc.RevisionNumber + 1,
NewFileSize: fc.FileSize,
NewFileMerkleRoot: fc.FileMerkleRoot,
NewWindowStart: fc.WindowStart,
NewWindowEnd: fc.WindowEnd,
NewValidProofOutputs: fc.ValidProofOutputs,
NewMissedProofOutputs: fc.MissedProofOutputs,
NewUnlockHash: fc.UnlockHash,
}
// createRevisionSignature will also perform validation on the result,
// returning an error if the renter provided an incorrect signature.
revisionTransaction, err := createRevisionSignature(noOpRevision, renterRevisionSignature, hostSK, blockHeight)
if err != nil {
return nil, types.TransactionSignature{}, types.FileContractID{}, err
}
// Create and add the storage obligation for this file contract.
fullTxn, _ := builder.View()
so := storageObligation{
SectorRoots: initialSectorRoots,
ContractCost: h.settings.MinContractPrice,
LockedCollateral: hostCollateral,
PotentialStorageRevenue: hostInitialRevenue,
RiskedCollateral: hostInitialRisk,
OriginTransactionSet: fullTxnSet,
RevisionTransactionSet: []types.Transaction{revisionTransaction},
}
// Get a lock on the storage obligation.
lockErr := h.managedTryLockStorageObligation(so.id())
if lockErr != nil {
build.Critical("failed to get a lock on a brand new storage obligation")
return nil, types.TransactionSignature{}, types.FileContractID{}, lockErr
}
defer func() {
if err != nil {
h.managedUnlockStorageObligation(so.id())
}
}()
// addStorageObligation will submit the transaction to the transaction
// pool, and will only do so if there was not some error in creating the
// storage obligation. If the transaction pool returns a consensus
// conflict, wait 30 seconds and try again.
err = func() error {
// Try adding the storage obligation. If there's an error, wait a few
// seconds and try again. Eventually time out. It should be noted that
// the storage obligation locking is both crappy and incomplete, and
// that I'm not sure how this timeout plays with the overall host
// timeouts.
//
// The storage obligation locks should occur at the highest level, not
// just when the actual modification is happening.
i := 0
for {
h.mu.Lock()
err = h.addStorageObligation(so)
h.mu.Unlock()
if err == nil {
return nil
}
if err != nil && i > 4 {
h.log.Println(err)
builder.Drop()
return err
}
i++
if build.Release == "standard" {
time.Sleep(time.Second * 15)
}
}
}()
if err != nil {
return nil, types.TransactionSignature{}, types.FileContractID{}, err
}
// Get the host's transaction signatures from the builder.
var hostTxnSignatures []types.TransactionSignature
_, _, _, txnSigIndices := builder.ViewAdded()
for _, sigIndex := range txnSigIndices {
hostTxnSignatures = append(hostTxnSignatures, fullTxn.TransactionSignatures[sigIndex])
}
return hostTxnSignatures, revisionTransaction.TransactionSignatures[1], so.id(), nil
}
// negotiateContract establishes a connection to a host and negotiates an
// initial file contract according to the terms of the host.
func negotiateContract(conn net.Conn, addr modules.NetAddress, fc types.FileContract, txnBuilder modules.TransactionBuilder, tpool modules.TransactionPool) (hostContract, error) {
// allow 30 seconds for negotiation
conn.SetDeadline(time.Now().Add(30 * time.Second))
// read host key
var hostPublicKey types.SiaPublicKey
if err := encoding.ReadObject(conn, &hostPublicKey, 256); err != nil {
return hostContract{}, errors.New("couldn't read host's public key: " + err.Error())
}
// create our key
ourSK, ourPK, err := crypto.GenerateKeyPair()
if err != nil {
return hostContract{}, errors.New("failed to generate keypair: " + err.Error())
}
ourPublicKey := types.SiaPublicKey{
Algorithm: types.SignatureEd25519,
Key: ourPK[:],
}
// send our public key
if err := encoding.WriteObject(conn, ourPublicKey); err != nil {
return hostContract{}, errors.New("couldn't send our public key: " + err.Error())
}
// create unlock conditions
uc := types.UnlockConditions{
PublicKeys: []types.SiaPublicKey{ourPublicKey, hostPublicKey},
SignaturesRequired: 2,
}
// add UnlockHash to file contract
fc.UnlockHash = uc.UnlockHash()
// build transaction containing fc
err = txnBuilder.FundSiacoins(fc.Payout)
if err != nil {
return hostContract{}, err
}
txnBuilder.AddFileContract(fc)
txn, parents := txnBuilder.View()
txnSet := append(parents, txn)
// calculate contract ID
fcid := txn.FileContractID(0) // TODO: is it actually 0?
// send txn
if err := encoding.WriteObject(conn, txnSet); err != nil {
return hostContract{}, errors.New("couldn't send our proposed contract: " + err.Error())
}
// read back acceptance
var response string
if err := encoding.ReadObject(conn, &response, 128); err != nil {
return hostContract{}, errors.New("couldn't read the host's response to our proposed contract: " + err.Error())
}
if response != modules.AcceptResponse {
return hostContract{}, errors.New("host rejected proposed contract: " + response)
}
// read back txn with host collateral.
var hostTxnSet []types.Transaction
if err := encoding.ReadObject(conn, &hostTxnSet, types.BlockSizeLimit); err != nil {
return hostContract{}, errors.New("couldn't read the host's updated contract: " + err.Error())
}
// check that txn is okay. For now, no collateral will be added, so the
// transaction sets should be identical.
if len(hostTxnSet) != len(txnSet) {
return hostContract{}, errors.New("host sent bad collateral transaction")
}
for i := range hostTxnSet {
if hostTxnSet[i].ID() != txnSet[i].ID() {
return hostContract{}, errors.New("host sent bad collateral transaction")
}
}
// sign the txn and resend
// NOTE: for now, we are assuming that the transaction has not changed
// since we sent it. Otherwise, the txnBuilder would have to be updated
// with whatever fields were added by the host.
signedTxnSet, err := txnBuilder.Sign(true)
if err != nil {
return hostContract{}, err
}
if err := encoding.WriteObject(conn, signedTxnSet); err != nil {
return hostContract{}, errors.New("couldn't send the contract signed by us: " + err.Error())
}
// read signed txn from host
var signedHostTxnSet []types.Transaction
if err := encoding.ReadObject(conn, &signedHostTxnSet, types.BlockSizeLimit); err != nil {
return hostContract{}, errors.New("couldn't read the contract signed by the host: " + err.Error())
}
// submit to blockchain
err = tpool.AcceptTransactionSet(signedHostTxnSet)
if err == modules.ErrDuplicateTransactionSet {
// this can happen if the renter is uploading to itself
err = nil
}
if err != nil {
return hostContract{}, err
}
// create host contract
hc := hostContract{
IP: addr,
ID: fcid,
FileContract: fc,
LastRevision: types.FileContractRevision{
ParentID: fcid,
UnlockConditions: uc,
NewRevisionNumber: fc.RevisionNumber,
NewFileSize: fc.FileSize,
NewFileMerkleRoot: fc.FileMerkleRoot,
NewWindowStart: fc.WindowStart,
NewWindowEnd: fc.WindowEnd,
NewValidProofOutputs: []types.SiacoinOutput{fc.ValidProofOutputs[0], fc.ValidProofOutputs[1]},
NewMissedProofOutputs: []types.SiacoinOutput{fc.MissedProofOutputs[0], fc.MissedProofOutputs[1]},
NewUnlockHash: fc.UnlockHash,
},
LastRevisionTxn: types.Transaction{},
SecretKey: ourSK,
}
return hc, nil
}