// threadedAcceptConn adds a connecting node as a peer.
func (g *Gateway) threadedAcceptConn(conn net.Conn) {
if g.threads.Add() != nil {
conn.Close()
return
}
defer g.threads.Done()
conn.SetDeadline(time.Now().Add(connStdDeadline))
addr := modules.NetAddress(conn.RemoteAddr().String())
g.log.Debugf("INFO: %v wants to connect", addr)
remoteVersion, err := acceptConnVersionHandshake(conn, build.Version)
if err != nil {
g.log.Debugf("INFO: %v wanted to connect but version handshake failed: %v", addr, err)
conn.Close()
return
}
if build.VersionCmp(remoteVersion, handshakeUpgradeVersion) < 0 {
err = g.managedAcceptConnOldPeer(conn, remoteVersion)
} else {
err = g.managedAcceptConnNewPeer(conn, remoteVersion)
}
if err != nil {
g.log.Debugf("INFO: %v wanted to connect, but failed: %v", addr, err)
conn.Close()
return
}
// Handshake successful, remove the deadline.
conn.SetDeadline(time.Time{})
g.log.Debugf("INFO: accepted connection from new peer %v (v%v)", addr, remoteVersion)
}
// threadedAcceptConn adds a connecting node as a peer.
func (g *Gateway) threadedAcceptConn(conn net.Conn) {
if g.threads.Add() != nil {
return
}
defer g.threads.Done()
addr := modules.NetAddress(conn.RemoteAddr().String())
g.log.Debugf("INFO: %v wants to connect", addr)
remoteVersion, err := acceptConnVersionHandshake(conn, build.Version)
if err != nil {
g.log.Debugf("INFO: %v wanted to connect but version handshake failed: %v", addr, err)
conn.Close()
return
}
if build.VersionCmp(remoteVersion, "1.0.0") < 0 {
err = g.managedAcceptConnOldPeer(conn, remoteVersion)
} else {
err = g.managedAcceptConnNewPeer(conn, remoteVersion)
}
if err != nil {
g.log.Debugf("INFO: %v wanted to connect, but failed: %v", addr, err)
conn.Close()
return
}
g.log.Debugf("INFO: accepted connection from new peer %v (v%v)", addr, remoteVersion)
}
// acceptConn adds a connecting node as a peer.
func (g *Gateway) acceptConn(conn net.Conn) {
addr := modules.NetAddress(conn.RemoteAddr().String())
g.log.Printf("INFO: %v wants to connect", addr)
// read version
var remoteVersion string
if err := encoding.ReadObject(conn, &remoteVersion, maxAddrLength); err != nil {
conn.Close()
g.log.Printf("INFO: %v wanted to connect, but we could not read their version: %v", addr, err)
return
}
// check that version is acceptable
// NOTE: this version must be bumped whenever the gateway or consensus
// breaks compatibility.
if build.VersionCmp(remoteVersion, "0.3.3") < 0 {
encoding.WriteObject(conn, "reject")
conn.Close()
g.log.Printf("INFO: %v wanted to connect, but their version (%v) was unacceptable", addr, remoteVersion)
return
}
// respond with our version
if err := encoding.WriteObject(conn, build.Version); err != nil {
conn.Close()
g.log.Printf("INFO: could not write version ack to %v: %v", addr, err)
return
}
// If we are already fully connected, kick out an old peer to make room
// for the new one. Importantly, prioritize kicking a peer with the same
// IP as the connecting peer. This protects against Sybil attacks.
id := g.mu.Lock()
if len(g.peers) >= fullyConnectedThreshold {
// first choose a random peer, preferably inbound. If have only
// outbound peers, we'll wind up kicking an outbound peer; but
// subsequent inbound connections will kick each other instead of
// continuing to replace outbound peers.
kick, err := g.randomInboundPeer()
if err != nil {
kick, _ = g.randomPeer()
}
// if another peer shares this IP, choose that one instead
for p := range g.peers {
if p.Host() == addr.Host() {
kick = p
break
}
}
g.peers[kick].sess.Close()
delete(g.peers, kick)
g.log.Printf("INFO: disconnected from %v to make room for %v", kick, addr)
}
// add the peer
g.addPeer(&peer{addr: addr, sess: muxado.Server(conn), inbound: true})
g.mu.Unlock(id)
g.log.Printf("INFO: accepted connection from new peer %v (v%v)", addr, remoteVersion)
}
// checkForUpdate checks a centralized server for a more recent version of
// Sia. If an update is available, it returns true, along with the newer
// version.
func checkForUpdate() (bool, string, error) {
manifest, err := fetchManifest("current")
if err != nil {
return false, "", err
}
version := manifest[0]
return build.VersionCmp(build.Version, version) < 0, version, nil
}
// acceptableVersion returns an error if the version is unacceptable.
func acceptableVersion(version string) error {
if !build.IsVersion(version) {
return invalidVersionError(version)
}
if build.VersionCmp(version, minAcceptableVersion) < 0 {
return insufficientVersionError(version)
}
return nil
}
// Connect establishes a persistent connection to a peer, and adds it to the
// Gateway's peer list.
func (g *Gateway) Connect(addr modules.NetAddress) error {
if addr == g.Address() {
return errors.New("can't connect to our own address")
}
id := g.mu.RLock()
_, exists := g.peers[addr]
g.mu.RUnlock(id)
if exists {
return errors.New("peer already added")
}
conn, err := net.DialTimeout("tcp", string(addr), dialTimeout)
if err != nil {
return err
}
// send our version
if err := encoding.WriteObject(conn, "0.3.3"); err != nil {
return err
}
// read version ack
var remoteVersion string
if err := encoding.ReadObject(conn, &remoteVersion, maxAddrLength); err != nil {
return err
} else if remoteVersion == "reject" {
return errors.New("peer rejected connection")
}
// decide whether to accept this version
if build.VersionCmp(remoteVersion, "0.3.3") < 0 {
conn.Close()
return errors.New("unacceptable version: " + remoteVersion)
}
g.log.Println("INFO: connected to new peer", addr)
id = g.mu.Lock()
g.addPeer(&peer{addr: addr, sess: muxado.Client(conn), inbound: false})
g.mu.Unlock(id)
// call initRPCs
id = g.mu.RLock()
var wg sync.WaitGroup
wg.Add(len(g.initRPCs))
for name, fn := range g.initRPCs {
go func(name string, fn modules.RPCFunc) {
// errors here are non-fatal
g.RPC(addr, name, fn)
wg.Done()
}(name, fn)
}
g.mu.RUnlock(id)
wg.Wait()
return nil
}
// managedBroadcastBlock will broadcast a block to the consensus set's peers.
func (cs *ConsensusSet) managedBroadcastBlock(b types.Block) {
// COMPATv0.5.1 - broadcast the block to all peers <= v0.5.1 and block header to all peers > v0.5.1.
var relayBlockPeers, relayHeaderPeers []modules.Peer
for _, p := range cs.gateway.Peers() {
if build.VersionCmp(p.Version, "0.5.1") <= 0 {
relayBlockPeers = append(relayBlockPeers, p)
} else {
relayHeaderPeers = append(relayHeaderPeers, p)
}
}
go cs.gateway.Broadcast("RelayBlock", b, relayBlockPeers)
go cs.gateway.Broadcast("RelayHeader", b.Header(), relayHeaderPeers)
}
// Editor initiates the contract revision process with a host, and returns
// an Editor.
func (c *Contractor) Editor(contract modules.RenterContract) (Editor, error) {
c.mu.RLock()
height := c.blockHeight
c.mu.RUnlock()
if height > contract.EndHeight() {
return nil, errors.New("contract has already ended")
}
host, ok := c.hdb.Host(contract.NetAddress)
if !ok {
return nil, errors.New("no record of that host")
}
if host.StoragePrice.Cmp(maxStoragePrice) > 0 {
return nil, errTooExpensive
}
// cap host.Collateral on new hosts
if build.VersionCmp(host.Version, "0.6.0") > 0 {
if host.Collateral.Cmp(maxUploadCollateral) > 0 {
host.Collateral = maxUploadCollateral
}
}
// create editor
e, err := proto.NewEditor(host, contract, height)
if proto.IsRevisionMismatch(err) {
// try again with the cached revision
c.mu.RLock()
cached, ok := c.cachedRevisions[contract.ID]
c.mu.RUnlock()
if !ok {
// nothing we can do; return original error
return nil, err
}
c.log.Printf("host %v has different revision for %v; retrying with cached revision", contract.NetAddress, contract.ID)
contract.LastRevision = cached.revision
contract.MerkleRoots = cached.merkleRoots
e, err = proto.NewEditor(host, contract, height)
}
if err != nil {
return nil, err
}
// supply a SaveFn that saves the revision to the contractor's persist
// (the existing revision will be overwritten when SaveFn is called)
e.SaveFn = c.saveRevision(contract.ID)
return &hostEditor{
editor: e,
contract: contract,
contractor: c,
}, nil
}
// acceptConn adds a connecting node as a peer.
func (g *Gateway) acceptConn(conn net.Conn) {
addr := modules.NetAddress(conn.RemoteAddr().String())
g.log.Printf("INFO: %v wants to connect", addr)
// don't connect to an IP address more than once
if build.Release != "testing" {
id := g.mu.RLock()
for p := range g.peers {
if p.Host() == addr.Host() {
g.mu.RUnlock(id)
conn.Close()
g.log.Printf("INFO: rejected connection from %v: already connected", addr)
return
}
}
g.mu.RUnlock(id)
}
// read version
var remoteVersion string
if err := encoding.ReadObject(conn, &remoteVersion, maxAddrLength); err != nil {
conn.Close()
g.log.Printf("INFO: %v wanted to connect, but we could not read their version: %v", addr, err)
return
}
// decide whether to accept
// NOTE: this version must be bumped whenever the gateway or consensus
// breaks compatibility.
if build.VersionCmp(remoteVersion, "0.3.3") < 0 {
encoding.WriteObject(conn, "reject")
conn.Close()
g.log.Printf("INFO: %v wanted to connect, but their version (%v) was unacceptable", addr, remoteVersion)
return
}
// respond with our version
if err := encoding.WriteObject(conn, "0.3.3"); err != nil {
conn.Close()
g.log.Printf("INFO: could not write version ack to %v: %v", addr, err)
return
}
// If we are already fully connected, kick out an old inbound peer to make
// room for the new one. Among other things, this ensures that bootstrap
// nodes will always be connectible. Worst case, you'll connect, receive a
// node list, and immediately get booted. But once you have the node list
// you should be able to connect to less full peers.
id := g.mu.Lock()
if len(g.peers) >= fullyConnectedThreshold {
oldPeer, err := g.randomInboundPeer()
if err == nil {
g.peers[oldPeer].sess.Close()
delete(g.peers, oldPeer)
g.log.Printf("INFO: disconnected from %v to make room for %v", oldPeer, addr)
}
}
// add the peer
g.addPeer(&peer{addr: addr, sess: muxado.Server(conn), inbound: true})
g.mu.Unlock(id)
g.log.Printf("INFO: accepted connection from new peer %v (v%v)", addr, remoteVersion)
}
// Connect establishes a persistent connection to a peer, and adds it to the
// Gateway's peer list.
func (g *Gateway) Connect(addr modules.NetAddress) error {
if err := g.threads.Add(); err != nil {
return err
}
defer g.threads.Done()
if addr == g.Address() {
return errors.New("can't connect to our own address")
}
if err := addr.IsValid(); err != nil {
return errors.New("can't connect to invalid address")
}
if net.ParseIP(addr.Host()) == nil {
return errors.New("address must be an IP address")
}
g.mu.RLock()
_, exists := g.peers[addr]
g.mu.RUnlock()
if exists {
return errors.New("peer already added")
}
conn, err := net.DialTimeout("tcp", string(addr), dialTimeout)
if err != nil {
return err
}
remoteVersion, err := connectVersionHandshake(conn, build.Version)
if err != nil {
conn.Close()
return err
}
if build.VersionCmp(remoteVersion, "1.0.0") < 0 {
err = g.managedConnectOldPeer(conn, remoteVersion, addr)
} else {
err = g.managedConnectNewPeer(conn, remoteVersion, addr)
}
if err != nil {
conn.Close()
return err
}
g.log.Debugln("INFO: connected to new peer", addr)
// call initRPCs
g.mu.RLock()
for name, fn := range g.initRPCs {
go func(name string, fn modules.RPCFunc) {
if g.threads.Add() != nil {
return
}
defer g.threads.Done()
err := g.RPC(addr, name, fn)
if err != nil {
g.log.Debugf("INFO: RPC %q on peer %q failed: %v", name, addr, err)
}
}(name, fn)
}
g.mu.RUnlock()
return nil
}
// managedReceiveBlocks is the calling end of the SendBlocks RPC, without the
// threadgroup wrapping.
func (cs *ConsensusSet) managedReceiveBlocks(conn modules.PeerConn) (returnErr error) {
// Set a deadline after which SendBlocks will timeout. During IBD, esepcially,
// SendBlocks will timeout. This is by design so that IBD switches peers to
// prevent any one peer from stalling IBD.
err := conn.SetDeadline(time.Now().Add(sendBlocksTimeout))
// Ignore errors returned by SetDeadline if the conn is a pipe in testing.
// Pipes do not support Set{,Read,Write}Deadline and should only be used in
// testing.
if opErr, ok := err.(*net.OpError); ok && opErr.Op == "set" && opErr.Net == "pipe" && build.Release == "testing" {
err = nil
}
if err != nil {
return err
}
stalled := true
defer func() {
// TODO: Timeout errors returned by muxado do not conform to the net.Error
// interface and therefore we cannot check if the error is a timeout using
// the Timeout() method. Once muxado issue #14 is resolved change the below
// condition to:
// if netErr, ok := returnErr.(net.Error); ok && netErr.Timeout() && stalled { ... }
if stalled && returnErr != nil && (returnErr.Error() == "Read timeout" || returnErr.Error() == "Write timeout") {
returnErr = errSendBlocksStalled
}
}()
// Get blockIDs to send.
var history [32]types.BlockID
cs.mu.RLock()
err = cs.db.View(func(tx *bolt.Tx) error {
history = blockHistory(tx)
return nil
})
cs.mu.RUnlock()
if err != nil {
return err
}
// Send the block ids.
if err := encoding.WriteObject(conn, history); err != nil {
return err
}
// Broadcast the last block accepted. This functionality is in a defer to
// ensure that a block is always broadcast if any blocks are accepted. This
// is to stop an attacker from preventing block broadcasts.
chainExtended := false
defer func() {
cs.mu.RLock()
synced := cs.synced
cs.mu.RUnlock()
if chainExtended && synced {
// The last block received will be the current block since
// managedAcceptBlock only returns nil if a block extends the longest chain.
currentBlock := cs.managedCurrentBlock()
// COMPATv0.5.1 - broadcast the block to all peers <= v0.5.1 and block header to all peers > v0.5.1
var relayBlockPeers, relayHeaderPeers []modules.Peer
for _, p := range cs.gateway.Peers() {
if build.VersionCmp(p.Version, "0.5.1") <= 0 {
relayBlockPeers = append(relayBlockPeers, p)
} else {
relayHeaderPeers = append(relayHeaderPeers, p)
}
}
go cs.gateway.Broadcast("RelayBlock", currentBlock, relayBlockPeers)
go cs.gateway.Broadcast("RelayHeader", currentBlock.Header(), relayHeaderPeers)
}
}()
// Read blocks off of the wire and add them to the consensus set until
// there are no more blocks available.
moreAvailable := true
for moreAvailable {
// Read a slice of blocks from the wire.
var newBlocks []types.Block
if err := encoding.ReadObject(conn, &newBlocks, uint64(MaxCatchUpBlocks)*types.BlockSizeLimit); err != nil {
return err
}
if err := encoding.ReadObject(conn, &moreAvailable, 1); err != nil {
return err
}
// Integrate the blocks into the consensus set.
for _, block := range newBlocks {
stalled = false
// Call managedAcceptBlock instead of AcceptBlock so as not to broadcast
// every block.
acceptErr := cs.managedAcceptBlock(block)
// Set a flag to indicate that we should broadcast the last block received.
if acceptErr == nil {
chainExtended = true
}
// ErrNonExtendingBlock must be ignored until headers-first block
// sharing is implemented, block already in database should also be
// ignored.
if acceptErr == modules.ErrNonExtendingBlock || acceptErr == modules.ErrBlockKnown {
acceptErr = nil
}
if acceptErr != nil {
return acceptErr
}
}
}
return nil
}
// managedConnect establishes a persistent connection to a peer, and adds it to
// the Gateway's peer list.
func (g *Gateway) managedConnect(addr modules.NetAddress) error {
// Perform verification on the input address.
g.mu.RLock()
gaddr := g.myAddr
g.mu.RUnlock()
if addr == gaddr {
return errors.New("can't connect to our own address")
}
if err := addr.IsStdValid(); err != nil {
return errors.New("can't connect to invalid address")
}
if net.ParseIP(addr.Host()) == nil {
return errors.New("address must be an IP address")
}
g.mu.RLock()
_, exists := g.peers[addr]
g.mu.RUnlock()
if exists {
return errPeerExists
}
// Dial the peer and perform peer initialization.
conn, err := g.dial(addr)
if err != nil {
return err
}
// Perform peer initialization.
remoteVersion, err := connectVersionHandshake(conn, build.Version)
if err != nil {
conn.Close()
return err
}
if build.VersionCmp(remoteVersion, handshakeUpgradeVersion) < 0 {
err = g.managedConnectOldPeer(conn, remoteVersion, addr)
} else {
err = g.managedConnectNewPeer(conn, remoteVersion, addr)
}
if err != nil {
conn.Close()
return err
}
g.log.Debugln("INFO: connected to new peer", addr)
// Connection successful, clear the timeout as to maintain a persistent
// connection to this peer.
conn.SetDeadline(time.Time{})
// call initRPCs
g.mu.RLock()
for name, fn := range g.initRPCs {
go func(name string, fn modules.RPCFunc) {
if g.threads.Add() != nil {
return
}
defer g.threads.Done()
err := g.managedRPC(addr, name, fn)
if err != nil {
g.log.Debugf("INFO: RPC %q on peer %q failed: %v", name, addr, err)
}
}(name, fn)
}
g.mu.RUnlock()
return nil
}