syncthing/lib/protocol/protocol.go

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// Copyright (C) 2014 The Protocol Authors.
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package protocol
import (
"context"
"crypto/sha256"
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"encoding/binary"
"fmt"
"io"
"path"
"strings"
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"sync"
"time"
lz4 "github.com/bkaradzic/go-lz4"
"github.com/pkg/errors"
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)
const (
// Shifts
KiB = 10
MiB = 20
GiB = 30
)
const (
// MaxMessageLen is the largest message size allowed on the wire. (500 MB)
MaxMessageLen = 500 * 1000 * 1000
// MinBlockSize is the minimum block size allowed
MinBlockSize = 128 << KiB
// MaxBlockSize is the maximum block size allowed
MaxBlockSize = 16 << MiB
// DesiredPerFileBlocks is the number of blocks we aim for per file
DesiredPerFileBlocks = 2000
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)
// BlockSizes is the list of valid block sizes, from min to max
var BlockSizes []int
// For each block size, the hash of a block of all zeroes
var sha256OfEmptyBlock = map[int][sha256.Size]byte{
128 << KiB: {0xfa, 0x43, 0x23, 0x9b, 0xce, 0xe7, 0xb9, 0x7c, 0xa6, 0x2f, 0x0, 0x7c, 0xc6, 0x84, 0x87, 0x56, 0xa, 0x39, 0xe1, 0x9f, 0x74, 0xf3, 0xdd, 0xe7, 0x48, 0x6d, 0xb3, 0xf9, 0x8d, 0xf8, 0xe4, 0x71},
256 << KiB: {0x8a, 0x39, 0xd2, 0xab, 0xd3, 0x99, 0x9a, 0xb7, 0x3c, 0x34, 0xdb, 0x24, 0x76, 0x84, 0x9c, 0xdd, 0xf3, 0x3, 0xce, 0x38, 0x9b, 0x35, 0x82, 0x68, 0x50, 0xf9, 0xa7, 0x0, 0x58, 0x9b, 0x4a, 0x90},
512 << KiB: {0x7, 0x85, 0x4d, 0x2f, 0xef, 0x29, 0x7a, 0x6, 0xba, 0x81, 0x68, 0x5e, 0x66, 0xc, 0x33, 0x2d, 0xe3, 0x6d, 0x5d, 0x18, 0xd5, 0x46, 0x92, 0x7d, 0x30, 0xda, 0xad, 0x6d, 0x7f, 0xda, 0x15, 0x41},
1 << MiB: {0x30, 0xe1, 0x49, 0x55, 0xeb, 0xf1, 0x35, 0x22, 0x66, 0xdc, 0x2f, 0xf8, 0x6, 0x7e, 0x68, 0x10, 0x46, 0x7, 0xe7, 0x50, 0xab, 0xb9, 0xd3, 0xb3, 0x65, 0x82, 0xb8, 0xaf, 0x90, 0x9f, 0xcb, 0x58},
2 << MiB: {0x56, 0x47, 0xf0, 0x5e, 0xc1, 0x89, 0x58, 0x94, 0x7d, 0x32, 0x87, 0x4e, 0xeb, 0x78, 0x8f, 0xa3, 0x96, 0xa0, 0x5d, 0xb, 0xab, 0x7c, 0x1b, 0x71, 0xf1, 0x12, 0xce, 0xb7, 0xe9, 0xb3, 0x1e, 0xee},
4 << MiB: {0xbb, 0x9f, 0x8d, 0xf6, 0x14, 0x74, 0xd2, 0x5e, 0x71, 0xfa, 0x0, 0x72, 0x23, 0x18, 0xcd, 0x38, 0x73, 0x96, 0xca, 0x17, 0x36, 0x60, 0x5e, 0x12, 0x48, 0x82, 0x1c, 0xc0, 0xde, 0x3d, 0x3a, 0xf8},
8 << MiB: {0x2d, 0xae, 0xb1, 0xf3, 0x60, 0x95, 0xb4, 0x4b, 0x31, 0x84, 0x10, 0xb3, 0xf4, 0xe8, 0xb5, 0xd9, 0x89, 0xdc, 0xc7, 0xbb, 0x2, 0x3d, 0x14, 0x26, 0xc4, 0x92, 0xda, 0xb0, 0xa3, 0x5, 0x3e, 0x74},
16 << MiB: {0x8, 0xa, 0xcf, 0x35, 0xa5, 0x7, 0xac, 0x98, 0x49, 0xcf, 0xcb, 0xa4, 0x7d, 0xc2, 0xad, 0x83, 0xe0, 0x1b, 0x75, 0x66, 0x3a, 0x51, 0x62, 0x79, 0xc8, 0xb9, 0xd2, 0x43, 0xb7, 0x19, 0x64, 0x3e},
}
func init() {
for blockSize := MinBlockSize; blockSize <= MaxBlockSize; blockSize *= 2 {
BlockSizes = append(BlockSizes, blockSize)
if _, ok := sha256OfEmptyBlock[blockSize]; !ok {
panic("missing hard coded value for sha256 of empty block")
}
}
BufferPool = newBufferPool()
}
// BlockSize returns the block size to use for the given file size
func BlockSize(fileSize int64) int {
var blockSize int
for _, blockSize = range BlockSizes {
if fileSize < DesiredPerFileBlocks*int64(blockSize) {
break
}
}
return blockSize
}
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const (
stateInitial = iota
stateReady
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)
// FileInfo.LocalFlags flags
const (
FlagLocalUnsupported = 1 << 0 // The kind is unsupported, e.g. symlinks on Windows
FlagLocalIgnored = 1 << 1 // Matches local ignore patterns
FlagLocalMustRescan = 1 << 2 // Doesn't match content on disk, must be rechecked fully
FlagLocalReceiveOnly = 1 << 3 // Change detected on receive only folder
// Flags that should result in the Invalid bit on outgoing updates
LocalInvalidFlags = FlagLocalUnsupported | FlagLocalIgnored | FlagLocalMustRescan | FlagLocalReceiveOnly
// Flags that should result in a file being in conflict with its
// successor, due to us not having an up to date picture of its state on
// disk.
LocalConflictFlags = FlagLocalUnsupported | FlagLocalIgnored | FlagLocalReceiveOnly
LocalAllFlags = FlagLocalUnsupported | FlagLocalIgnored | FlagLocalMustRescan | FlagLocalReceiveOnly
)
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var (
ErrClosed = errors.New("connection closed")
ErrTimeout = errors.New("read timeout")
errUnknownMessage = errors.New("unknown message")
errInvalidFilename = errors.New("filename is invalid")
errUncleanFilename = errors.New("filename not in canonical format")
errDeletedHasBlocks = errors.New("deleted file with non-empty block list")
errDirectoryHasBlocks = errors.New("directory with non-empty block list")
errFileHasNoBlocks = errors.New("file with empty block list")
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)
type Model interface {
// An index was received from the peer device
Index(deviceID DeviceID, folder string, files []FileInfo) error
// An index update was received from the peer device
IndexUpdate(deviceID DeviceID, folder string, files []FileInfo) error
// A request was made by the peer device
Request(deviceID DeviceID, folder, name string, size int32, offset int64, hash []byte, weakHash uint32, fromTemporary bool) (RequestResponse, error)
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// A cluster configuration message was received
ClusterConfig(deviceID DeviceID, config ClusterConfig) error
// The peer device closed the connection
Closed(conn Connection, err error)
// The peer device sent progress updates for the files it is currently downloading
DownloadProgress(deviceID DeviceID, folder string, updates []FileDownloadProgressUpdate) error
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}
type RequestResponse interface {
Data() []byte
Close() // Must always be called once the byte slice is no longer in use
Wait() // Blocks until Close is called
}
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type Connection interface {
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Start()
Close(err error)
ID() DeviceID
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Name() string
Index(ctx context.Context, folder string, files []FileInfo) error
IndexUpdate(ctx context.Context, folder string, files []FileInfo) error
Request(ctx context.Context, folder string, name string, offset int64, size int, hash []byte, weakHash uint32, fromTemporary bool) ([]byte, error)
ClusterConfig(config ClusterConfig)
DownloadProgress(ctx context.Context, folder string, updates []FileDownloadProgressUpdate)
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Statistics() Statistics
Closed() bool
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}
type rawConnection struct {
id DeviceID
name string
receiver Model
startTime time.Time
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cr *countingReader
cw *countingWriter
awaiting map[int]chan asyncResult
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awaitingMut sync.Mutex
idxMut sync.Mutex // ensures serialization of Index calls
nextID int
nextIDMut sync.Mutex
inbox chan message
outbox chan asyncMessage
closeBox chan asyncMessage
clusterConfigBox chan *ClusterConfig
dispatcherLoopStopped chan struct{}
closed chan struct{}
closeOnce sync.Once
sendCloseOnce sync.Once
compression Compression
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}
type asyncResult struct {
val []byte
err error
}
type message interface {
ProtoSize() int
Marshal() ([]byte, error)
MarshalTo([]byte) (int, error)
Unmarshal([]byte) error
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}
type asyncMessage struct {
msg message
done chan struct{} // done closes when we're done sending the message
}
const (
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// PingSendInterval is how often we make sure to send a message, by
// triggering pings if necessary.
PingSendInterval = 90 * time.Second
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// ReceiveTimeout is the longest we'll wait for a message from the other
// side before closing the connection.
ReceiveTimeout = 300 * time.Second
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)
// CloseTimeout is the longest we'll wait when trying to send the close
// message before just closing the connection.
// Should not be modified in production code, just for testing.
var CloseTimeout = 10 * time.Second
func NewConnection(deviceID DeviceID, reader io.Reader, writer io.Writer, receiver Model, name string, compress Compression) Connection {
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cr := &countingReader{Reader: reader}
cw := &countingWriter{Writer: writer}
c := rawConnection{
id: deviceID,
name: name,
receiver: nativeModel{receiver},
cr: cr,
cw: cw,
awaiting: make(map[int]chan asyncResult),
inbox: make(chan message),
outbox: make(chan asyncMessage),
closeBox: make(chan asyncMessage),
clusterConfigBox: make(chan *ClusterConfig),
dispatcherLoopStopped: make(chan struct{}),
closed: make(chan struct{}),
compression: compress,
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}
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return wireFormatConnection{&c}
}
// Start creates the goroutines for sending and receiving of messages. It must
// be called exactly once after creating a connection.
func (c *rawConnection) Start() {
go c.readerLoop()
go func() {
err := c.dispatcherLoop()
c.internalClose(err)
}()
go c.writerLoop()
go c.pingSender()
go c.pingReceiver()
c.startTime = time.Now()
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}
func (c *rawConnection) ID() DeviceID {
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return c.id
}
func (c *rawConnection) Name() string {
return c.name
}
// Index writes the list of file information to the connected peer device
func (c *rawConnection) Index(ctx context.Context, folder string, idx []FileInfo) error {
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select {
case <-c.closed:
return ErrClosed
default:
}
c.idxMut.Lock()
c.send(ctx, &Index{
Folder: folder,
Files: idx,
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}, nil)
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c.idxMut.Unlock()
return nil
}
// IndexUpdate writes the list of file information to the connected peer device as an update
func (c *rawConnection) IndexUpdate(ctx context.Context, folder string, idx []FileInfo) error {
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select {
case <-c.closed:
return ErrClosed
default:
}
c.idxMut.Lock()
c.send(ctx, &IndexUpdate{
Folder: folder,
Files: idx,
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}, nil)
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c.idxMut.Unlock()
return nil
}
// Request returns the bytes for the specified block after fetching them from the connected peer.
func (c *rawConnection) Request(ctx context.Context, folder string, name string, offset int64, size int, hash []byte, weakHash uint32, fromTemporary bool) ([]byte, error) {
c.nextIDMut.Lock()
id := c.nextID
c.nextID++
c.nextIDMut.Unlock()
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c.awaitingMut.Lock()
if _, ok := c.awaiting[id]; ok {
c.awaitingMut.Unlock()
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panic("id taken")
}
rc := make(chan asyncResult, 1)
c.awaiting[id] = rc
c.awaitingMut.Unlock()
ok := c.send(ctx, &Request{
ID: id,
Folder: folder,
Name: name,
Offset: offset,
Size: size,
Hash: hash,
WeakHash: weakHash,
FromTemporary: fromTemporary,
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}, nil)
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if !ok {
return nil, ErrClosed
}
select {
case res, ok := <-rc:
if !ok {
return nil, ErrClosed
}
return res.val, res.err
case <-ctx.Done():
return nil, ctx.Err()
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}
}
// ClusterConfig sends the cluster configuration message to the peer.
func (c *rawConnection) ClusterConfig(config ClusterConfig) {
select {
case c.clusterConfigBox <- &config:
case <-c.closed:
}
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}
func (c *rawConnection) Closed() bool {
select {
case <-c.closed:
return true
default:
return false
}
}
// DownloadProgress sends the progress updates for the files that are currently being downloaded.
func (c *rawConnection) DownloadProgress(ctx context.Context, folder string, updates []FileDownloadProgressUpdate) {
c.send(ctx, &DownloadProgress{
Folder: folder,
Updates: updates,
}, nil)
}
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func (c *rawConnection) ping() bool {
return c.send(context.Background(), &Ping{}, nil)
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}
func (c *rawConnection) readerLoop() {
fourByteBuf := make([]byte, 4)
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for {
msg, err := c.readMessage(fourByteBuf)
if err != nil {
if err == errUnknownMessage {
// Unknown message types are skipped, for future extensibility.
continue
}
c.internalClose(err)
return
}
select {
case c.inbox <- msg:
case <-c.closed:
return
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}
}
}
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func (c *rawConnection) dispatcherLoop() (err error) {
defer close(c.dispatcherLoopStopped)
var msg message
state := stateInitial
for {
select {
case msg = <-c.inbox:
case <-c.closed:
return ErrClosed
}
switch msg := msg.(type) {
case *ClusterConfig:
l.Debugln("read ClusterConfig message")
if state == stateInitial {
state = stateReady
}
if err := c.receiver.ClusterConfig(c.id, *msg); err != nil {
return errors.Wrap(err, "receiver error")
}
case *Index:
l.Debugln("read Index message")
if state != stateReady {
return fmt.Errorf("protocol error: index message in state %d", state)
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}
if err := checkIndexConsistency(msg.Files); err != nil {
return errors.Wrap(err, "protocol error: index")
}
if err := c.handleIndex(*msg); err != nil {
return errors.Wrap(err, "receiver error")
}
state = stateReady
case *IndexUpdate:
l.Debugln("read IndexUpdate message")
if state != stateReady {
return fmt.Errorf("protocol error: index update message in state %d", state)
}
if err := checkIndexConsistency(msg.Files); err != nil {
return errors.Wrap(err, "protocol error: index update")
}
if err := c.handleIndexUpdate(*msg); err != nil {
return errors.Wrap(err, "receiver error")
}
state = stateReady
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case *Request:
l.Debugln("read Request message")
if state != stateReady {
return fmt.Errorf("protocol error: request message in state %d", state)
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}
if err := checkFilename(msg.Name); err != nil {
return errors.Wrapf(err, "protocol error: request: %q", msg.Name)
}
go c.handleRequest(*msg)
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case *Response:
l.Debugln("read Response message")
if state != stateReady {
return fmt.Errorf("protocol error: response message in state %d", state)
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}
c.handleResponse(*msg)
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case *DownloadProgress:
l.Debugln("read DownloadProgress message")
if state != stateReady {
return fmt.Errorf("protocol error: response message in state %d", state)
}
if err := c.receiver.DownloadProgress(c.id, msg.Folder, msg.Updates); err != nil {
return errors.Wrap(err, "receiver error")
}
case *Ping:
l.Debugln("read Ping message")
if state != stateReady {
return fmt.Errorf("protocol error: ping message in state %d", state)
}
// Nothing
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case *Close:
l.Debugln("read Close message")
return errors.New(msg.Reason)
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default:
l.Debugf("read unknown message: %+T", msg)
return fmt.Errorf("protocol error: %s: unknown or empty message", c.id)
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}
}
}
func (c *rawConnection) readMessage(fourByteBuf []byte) (message, error) {
hdr, err := c.readHeader(fourByteBuf)
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if err != nil {
return nil, err
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}
return c.readMessageAfterHeader(hdr, fourByteBuf)
}
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func (c *rawConnection) readMessageAfterHeader(hdr Header, fourByteBuf []byte) (message, error) {
// First comes a 4 byte message length
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if _, err := io.ReadFull(c.cr, fourByteBuf[:4]); err != nil {
return nil, errors.Wrap(err, "reading message length")
}
msgLen := int32(binary.BigEndian.Uint32(fourByteBuf))
if msgLen < 0 {
return nil, fmt.Errorf("negative message length %d", msgLen)
} else if msgLen > MaxMessageLen {
return nil, fmt.Errorf("message length %d exceeds maximum %d", msgLen, MaxMessageLen)
}
// Then comes the message
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buf := BufferPool.Get(int(msgLen))
if _, err := io.ReadFull(c.cr, buf); err != nil {
return nil, errors.Wrap(err, "reading message")
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}
// ... which might be compressed
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switch hdr.Compression {
case MessageCompressionNone:
// Nothing
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case MessageCompressionLZ4:
decomp, err := c.lz4Decompress(buf)
BufferPool.Put(buf)
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if err != nil {
return nil, errors.Wrap(err, "decompressing message")
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}
buf = decomp
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default:
return nil, fmt.Errorf("unknown message compression %d", hdr.Compression)
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}
// ... and is then unmarshalled
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msg, err := c.newMessage(hdr.Type)
if err != nil {
return nil, err
}
if err := msg.Unmarshal(buf); err != nil {
return nil, errors.Wrap(err, "unmarshalling message")
}
BufferPool.Put(buf)
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return msg, nil
}
func (c *rawConnection) readHeader(fourByteBuf []byte) (Header, error) {
// First comes a 2 byte header length
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if _, err := io.ReadFull(c.cr, fourByteBuf[:2]); err != nil {
return Header{}, errors.Wrap(err, "reading length")
}
hdrLen := int16(binary.BigEndian.Uint16(fourByteBuf))
if hdrLen < 0 {
return Header{}, fmt.Errorf("negative header length %d", hdrLen)
}
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// Then comes the header
buf := BufferPool.Get(int(hdrLen))
if _, err := io.ReadFull(c.cr, buf); err != nil {
return Header{}, errors.Wrap(err, "reading header")
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}
var hdr Header
if err := hdr.Unmarshal(buf); err != nil {
return Header{}, errors.Wrap(err, "unmarshalling header")
}
BufferPool.Put(buf)
return hdr, nil
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}
func (c *rawConnection) handleIndex(im Index) error {
l.Debugf("Index(%v, %v, %d file)", c.id, im.Folder, len(im.Files))
return c.receiver.Index(c.id, im.Folder, im.Files)
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}
func (c *rawConnection) handleIndexUpdate(im IndexUpdate) error {
l.Debugf("queueing IndexUpdate(%v, %v, %d files)", c.id, im.Folder, len(im.Files))
return c.receiver.IndexUpdate(c.id, im.Folder, im.Files)
}
// checkIndexConsistency verifies a number of invariants on FileInfos received in
// index messages.
func checkIndexConsistency(fs []FileInfo) error {
for _, f := range fs {
if err := checkFileInfoConsistency(f); err != nil {
return errors.Wrapf(err, "%q", f.Name)
}
}
return nil
}
// checkFileInfoConsistency verifies a number of invariants on the given FileInfo
func checkFileInfoConsistency(f FileInfo) error {
if err := checkFilename(f.Name); err != nil {
return err
}
switch {
case f.Deleted && len(f.Blocks) != 0:
// Deleted files should have no blocks
return errDeletedHasBlocks
case f.Type == FileInfoTypeDirectory && len(f.Blocks) != 0:
// Directories should have no blocks
return errDirectoryHasBlocks
case !f.Deleted && !f.IsInvalid() && f.Type == FileInfoTypeFile && len(f.Blocks) == 0:
// Non-deleted, non-invalid files should have at least one block
return errFileHasNoBlocks
}
return nil
}
// checkFilename verifies that the given filename is valid according to the
// spec on what's allowed over the wire. A filename failing this test is
// grounds for disconnecting the device.
func checkFilename(name string) error {
cleanedName := path.Clean(name)
if cleanedName != name {
// The filename on the wire should be in canonical format. If
// Clean() managed to clean it up, there was something wrong with
// it.
return errUncleanFilename
}
switch name {
case "", ".", "..":
// These names are always invalid.
return errInvalidFilename
}
if strings.HasPrefix(name, "/") {
// Names are folder relative, not absolute.
return errInvalidFilename
}
if strings.HasPrefix(name, "../") {
// Starting with a dotdot is not allowed. Any other dotdots would
// have been handled by the Clean() call at the top.
return errInvalidFilename
}
return nil
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}
func (c *rawConnection) handleRequest(req Request) {
res, err := c.receiver.Request(c.id, req.Folder, req.Name, int32(req.Size), req.Offset, req.Hash, req.WeakHash, req.FromTemporary)
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if err != nil {
c.send(context.Background(), &Response{
ID: req.ID,
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Code: errorToCode(err),
}, nil)
return
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}
done := make(chan struct{})
c.send(context.Background(), &Response{
ID: req.ID,
Data: res.Data(),
Code: errorToCode(nil),
}, done)
<-done
res.Close()
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}
func (c *rawConnection) handleResponse(resp Response) {
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c.awaitingMut.Lock()
if rc := c.awaiting[resp.ID]; rc != nil {
delete(c.awaiting, resp.ID)
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rc <- asyncResult{resp.Data, codeToError(resp.Code)}
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close(rc)
}
c.awaitingMut.Unlock()
}
func (c *rawConnection) send(ctx context.Context, msg message, done chan struct{}) bool {
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select {
case c.outbox <- asyncMessage{msg, done}:
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return true
case <-c.closed:
case <-ctx.Done():
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}
if done != nil {
close(done)
}
return false
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}
func (c *rawConnection) writerLoop() {
select {
case cc := <-c.clusterConfigBox:
err := c.writeMessage(cc)
if err != nil {
c.internalClose(err)
return
}
case hm := <-c.closeBox:
_ = c.writeMessage(hm.msg)
close(hm.done)
return
case <-c.closed:
return
}
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for {
select {
case cc := <-c.clusterConfigBox:
err := c.writeMessage(cc)
if err != nil {
c.internalClose(err)
return
}
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case hm := <-c.outbox:
err := c.writeMessage(hm.msg)
if hm.done != nil {
close(hm.done)
}
if err != nil {
c.internalClose(err)
return
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}
case hm := <-c.closeBox:
_ = c.writeMessage(hm.msg)
close(hm.done)
return
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case <-c.closed:
return
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}
}
}
func (c *rawConnection) writeMessage(msg message) error {
if c.shouldCompressMessage(msg) {
return c.writeCompressedMessage(msg)
}
return c.writeUncompressedMessage(msg)
}
func (c *rawConnection) writeCompressedMessage(msg message) error {
size := msg.ProtoSize()
buf := BufferPool.Get(size)
if _, err := msg.MarshalTo(buf); err != nil {
return errors.Wrap(err, "marshalling message")
}
compressed, err := c.lz4Compress(buf)
if err != nil {
return errors.Wrap(err, "compressing message")
}
hdr := Header{
Type: c.typeOf(msg),
Compression: MessageCompressionLZ4,
}
hdrSize := hdr.ProtoSize()
if hdrSize > 1<<16-1 {
panic("impossibly large header")
}
totSize := 2 + hdrSize + 4 + len(compressed)
buf = BufferPool.Upgrade(buf, totSize)
// Header length
binary.BigEndian.PutUint16(buf, uint16(hdrSize))
// Header
if _, err := hdr.MarshalTo(buf[2:]); err != nil {
return errors.Wrap(err, "marshalling header")
}
// Message length
binary.BigEndian.PutUint32(buf[2+hdrSize:], uint32(len(compressed)))
// Message
copy(buf[2+hdrSize+4:], compressed)
BufferPool.Put(compressed)
n, err := c.cw.Write(buf)
BufferPool.Put(buf)
l.Debugf("wrote %d bytes on the wire (2 bytes length, %d bytes header, 4 bytes message length, %d bytes message (%d uncompressed)), err=%v", n, hdrSize, len(compressed), size, err)
if err != nil {
return errors.Wrap(err, "writing message")
}
return nil
}
func (c *rawConnection) writeUncompressedMessage(msg message) error {
size := msg.ProtoSize()
hdr := Header{
Type: c.typeOf(msg),
}
hdrSize := hdr.ProtoSize()
if hdrSize > 1<<16-1 {
panic("impossibly large header")
}
totSize := 2 + hdrSize + 4 + size
buf := BufferPool.Get(totSize)
// Header length
binary.BigEndian.PutUint16(buf, uint16(hdrSize))
// Header
if _, err := hdr.MarshalTo(buf[2:]); err != nil {
return errors.Wrap(err, "marshalling header")
}
// Message length
binary.BigEndian.PutUint32(buf[2+hdrSize:], uint32(size))
// Message
if _, err := msg.MarshalTo(buf[2+hdrSize+4:]); err != nil {
return errors.Wrap(err, "marshalling message")
}
n, err := c.cw.Write(buf[:totSize])
BufferPool.Put(buf)
l.Debugf("wrote %d bytes on the wire (2 bytes length, %d bytes header, 4 bytes message length, %d bytes message), err=%v", n, hdrSize, size, err)
if err != nil {
return errors.Wrap(err, "writing message")
}
return nil
}
func (c *rawConnection) typeOf(msg message) MessageType {
switch msg.(type) {
case *ClusterConfig:
return MessageTypeClusterConfig
case *Index:
return MessageTypeIndex
case *IndexUpdate:
return MessageTypeIndexUpdate
case *Request:
return MessageTypeRequest
case *Response:
return MessageTypeResponse
case *DownloadProgress:
return MessageTypeDownloadProgress
case *Ping:
return MessageTypePing
case *Close:
return MessageTypeClose
default:
panic("bug: unknown message type")
}
}
func (c *rawConnection) newMessage(t MessageType) (message, error) {
switch t {
case MessageTypeClusterConfig:
return new(ClusterConfig), nil
case MessageTypeIndex:
return new(Index), nil
case MessageTypeIndexUpdate:
return new(IndexUpdate), nil
case MessageTypeRequest:
return new(Request), nil
case MessageTypeResponse:
return new(Response), nil
case MessageTypeDownloadProgress:
return new(DownloadProgress), nil
case MessageTypePing:
return new(Ping), nil
case MessageTypeClose:
return new(Close), nil
default:
return nil, errUnknownMessage
}
}
func (c *rawConnection) shouldCompressMessage(msg message) bool {
switch c.compression {
case CompressionNever:
return false
case CompressionAlways:
// Use compression for large enough messages
return msg.ProtoSize() >= compressionThreshold
case CompressionMetadata:
_, isResponse := msg.(*Response)
// Compress if it's large enough and not a response message
return !isResponse && msg.ProtoSize() >= compressionThreshold
default:
panic("unknown compression setting")
}
}
// Close is called when the connection is regularely closed and thus the Close
// BEP message is sent before terminating the actual connection. The error
// argument specifies the reason for closing the connection.
func (c *rawConnection) Close(err error) {
c.sendCloseOnce.Do(func() {
done := make(chan struct{})
timeout := time.NewTimer(CloseTimeout)
select {
case c.closeBox <- asyncMessage{&Close{err.Error()}, done}:
select {
case <-done:
case <-timeout.C:
case <-c.closed:
}
case <-timeout.C:
case <-c.closed:
}
})
// Close might be called from a method that is called from within
// dispatcherLoop, resulting in a deadlock.
// The sending above must happen before spawning the routine, to prevent
// the underlying connection from terminating before sending the close msg.
go c.internalClose(err)
}
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// internalClose is called if there is an unexpected error during normal operation.
func (c *rawConnection) internalClose(err error) {
c.closeOnce.Do(func() {
l.Debugln("close due to", err)
close(c.closed)
c.awaitingMut.Lock()
for i, ch := range c.awaiting {
if ch != nil {
close(ch)
delete(c.awaiting, i)
}
}
c.awaitingMut.Unlock()
<-c.dispatcherLoopStopped
c.receiver.Closed(c, err)
})
}
// The pingSender makes sure that we've sent a message within the last
// PingSendInterval. If we already have something sent in the last
// PingSendInterval/2, we do nothing. Otherwise we send a ping message. This
// results in an effecting ping interval of somewhere between
// PingSendInterval/2 and PingSendInterval.
func (c *rawConnection) pingSender() {
ticker := time.NewTicker(PingSendInterval / 2)
defer ticker.Stop()
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for {
select {
case <-ticker.C:
d := time.Since(c.cw.Last())
if d < PingSendInterval/2 {
Implement facility based logger, debugging via REST API This implements a new debug/trace infrastructure based on a slightly hacked up logger. Instead of the traditional "if debug { ... }" I've rewritten the logger to have no-op Debugln and Debugf, unless debugging has been enabled for a given "facility". The "facility" is just a string, typically a package name. This will be slightly slower than before; but not that much as it's mostly a function call that returns immediately. For the cases where it matters (the Debugln takes a hex.Dump() of something for example, and it's not in a very occasional "if err != nil" branch) there is an l.ShouldDebug(facility) that is fast enough to be used like the old "if debug". The point of all this is that we can now toggle debugging for the various packages on and off at runtime. There's a new method /rest/system/debug that can be POSTed a set of facilities to enable and disable debug for, or GET from to get a list of facilities with descriptions and their current debug status. Similarly a /rest/system/log?since=... can grab the latest log entries, up to 250 of them (hardcoded constant in main.go) plus the initial few. Not implemented in this commit (but planned) is a simple debug GUI available on /debug that shows the current log in an easily pasteable format and has checkboxes to enable the various debug facilities. The debug instructions to a user then becomes "visit this URL, check these boxes, reproduce your problem, copy and paste the log". The actual log viewer on the hypothetical /debug URL can poll regularly for new log entries and this bypass the 250 line limit. The existing STTRACE=foo variable is still obeyed and just sets the start state of the system.
2015-10-03 15:25:21 +00:00
l.Debugln(c.id, "ping skipped after wr", d)
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continue
}
Implement facility based logger, debugging via REST API This implements a new debug/trace infrastructure based on a slightly hacked up logger. Instead of the traditional "if debug { ... }" I've rewritten the logger to have no-op Debugln and Debugf, unless debugging has been enabled for a given "facility". The "facility" is just a string, typically a package name. This will be slightly slower than before; but not that much as it's mostly a function call that returns immediately. For the cases where it matters (the Debugln takes a hex.Dump() of something for example, and it's not in a very occasional "if err != nil" branch) there is an l.ShouldDebug(facility) that is fast enough to be used like the old "if debug". The point of all this is that we can now toggle debugging for the various packages on and off at runtime. There's a new method /rest/system/debug that can be POSTed a set of facilities to enable and disable debug for, or GET from to get a list of facilities with descriptions and their current debug status. Similarly a /rest/system/log?since=... can grab the latest log entries, up to 250 of them (hardcoded constant in main.go) plus the initial few. Not implemented in this commit (but planned) is a simple debug GUI available on /debug that shows the current log in an easily pasteable format and has checkboxes to enable the various debug facilities. The debug instructions to a user then becomes "visit this URL, check these boxes, reproduce your problem, copy and paste the log". The actual log viewer on the hypothetical /debug URL can poll regularly for new log entries and this bypass the 250 line limit. The existing STTRACE=foo variable is still obeyed and just sets the start state of the system.
2015-10-03 15:25:21 +00:00
l.Debugln(c.id, "ping -> after", d)
c.ping()
case <-c.closed:
return
}
}
}
// The pingReceiver checks that we've received a message (any message will do,
// but we expect pings in the absence of other messages) within the last
// ReceiveTimeout. If not, we close the connection with an ErrTimeout.
func (c *rawConnection) pingReceiver() {
ticker := time.NewTicker(ReceiveTimeout / 2)
defer ticker.Stop()
for {
select {
case <-ticker.C:
d := time.Since(c.cr.Last())
if d > ReceiveTimeout {
Implement facility based logger, debugging via REST API This implements a new debug/trace infrastructure based on a slightly hacked up logger. Instead of the traditional "if debug { ... }" I've rewritten the logger to have no-op Debugln and Debugf, unless debugging has been enabled for a given "facility". The "facility" is just a string, typically a package name. This will be slightly slower than before; but not that much as it's mostly a function call that returns immediately. For the cases where it matters (the Debugln takes a hex.Dump() of something for example, and it's not in a very occasional "if err != nil" branch) there is an l.ShouldDebug(facility) that is fast enough to be used like the old "if debug". The point of all this is that we can now toggle debugging for the various packages on and off at runtime. There's a new method /rest/system/debug that can be POSTed a set of facilities to enable and disable debug for, or GET from to get a list of facilities with descriptions and their current debug status. Similarly a /rest/system/log?since=... can grab the latest log entries, up to 250 of them (hardcoded constant in main.go) plus the initial few. Not implemented in this commit (but planned) is a simple debug GUI available on /debug that shows the current log in an easily pasteable format and has checkboxes to enable the various debug facilities. The debug instructions to a user then becomes "visit this URL, check these boxes, reproduce your problem, copy and paste the log". The actual log viewer on the hypothetical /debug URL can poll regularly for new log entries and this bypass the 250 line limit. The existing STTRACE=foo variable is still obeyed and just sets the start state of the system.
2015-10-03 15:25:21 +00:00
l.Debugln(c.id, "ping timeout", d)
c.internalClose(ErrTimeout)
}
Implement facility based logger, debugging via REST API This implements a new debug/trace infrastructure based on a slightly hacked up logger. Instead of the traditional "if debug { ... }" I've rewritten the logger to have no-op Debugln and Debugf, unless debugging has been enabled for a given "facility". The "facility" is just a string, typically a package name. This will be slightly slower than before; but not that much as it's mostly a function call that returns immediately. For the cases where it matters (the Debugln takes a hex.Dump() of something for example, and it's not in a very occasional "if err != nil" branch) there is an l.ShouldDebug(facility) that is fast enough to be used like the old "if debug". The point of all this is that we can now toggle debugging for the various packages on and off at runtime. There's a new method /rest/system/debug that can be POSTed a set of facilities to enable and disable debug for, or GET from to get a list of facilities with descriptions and their current debug status. Similarly a /rest/system/log?since=... can grab the latest log entries, up to 250 of them (hardcoded constant in main.go) plus the initial few. Not implemented in this commit (but planned) is a simple debug GUI available on /debug that shows the current log in an easily pasteable format and has checkboxes to enable the various debug facilities. The debug instructions to a user then becomes "visit this URL, check these boxes, reproduce your problem, copy and paste the log". The actual log viewer on the hypothetical /debug URL can poll regularly for new log entries and this bypass the 250 line limit. The existing STTRACE=foo variable is still obeyed and just sets the start state of the system.
2015-10-03 15:25:21 +00:00
l.Debugln(c.id, "last read within", d)
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case <-c.closed:
return
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}
}
}
type Statistics struct {
At time.Time
InBytesTotal int64
OutBytesTotal int64
StartedAt time.Time
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}
func (c *rawConnection) Statistics() Statistics {
return Statistics{
At: time.Now(),
InBytesTotal: c.cr.Tot(),
OutBytesTotal: c.cw.Tot(),
StartedAt: c.startTime,
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}
}
func (c *rawConnection) lz4Compress(src []byte) ([]byte, error) {
var err error
buf := BufferPool.Get(lz4.CompressBound(len(src)))
compressed, err := lz4.Encode(buf, src)
if err != nil {
return nil, err
}
if &compressed[0] != &buf[0] {
panic("bug: lz4.Compress allocated, which it must not (should use buffer pool)")
}
binary.BigEndian.PutUint32(compressed, binary.LittleEndian.Uint32(compressed))
return compressed, nil
}
func (c *rawConnection) lz4Decompress(src []byte) ([]byte, error) {
size := binary.BigEndian.Uint32(src)
binary.LittleEndian.PutUint32(src, size)
var err error
buf := BufferPool.Get(int(size))
decoded, err := lz4.Decode(buf, src)
if err != nil {
return nil, err
}
if &decoded[0] != &buf[0] {
panic("bug: lz4.Decode allocated, which it must not (should use buffer pool)")
}
return decoded, nil
}