// Copyright (C) 2014 The Protocol Authors. package protocol import ( "bytes" "encoding/binary" "encoding/json" "errors" "fmt" "time" "github.com/syncthing/syncthing/lib/build" "github.com/syncthing/syncthing/lib/rand" "github.com/syncthing/syncthing/lib/sha256" ) const ( SyntheticDirectorySize = 128 HelloMessageMagic uint32 = 0x2EA7D90B Version13HelloMagic uint32 = 0x9F79BC40 // old ) // FileIntf is the set of methods implemented by both FileInfo and // db.FileInfoTruncated. type FileIntf interface { FileSize() int64 FileName() string FileLocalFlags() uint32 IsDeleted() bool IsInvalid() bool IsIgnored() bool IsUnsupported() bool MustRescan() bool IsReceiveOnlyChanged() bool IsDirectory() bool IsSymlink() bool ShouldConflict() bool HasPermissionBits() bool SequenceNo() int64 BlockSize() int FileVersion() Vector FileType() FileInfoType FilePermissions() uint32 FileModifiedBy() ShortID ModTime() time.Time PlatformData() PlatformData InodeChangeTime() time.Time FileBlocksHash() []byte } func (Hello) Magic() uint32 { return HelloMessageMagic } func (f FileInfo) String() string { switch f.Type { case FileInfoTypeDirectory: return fmt.Sprintf("Directory{Name:%q, Sequence:%d, Permissions:0%o, ModTime:%v, Version:%v, VersionHash:%x, Deleted:%v, Invalid:%v, LocalFlags:0x%x, NoPermissions:%v, Platform:%v, InodeChangeTime:%v}", f.Name, f.Sequence, f.Permissions, f.ModTime(), f.Version, f.VersionHash, f.Deleted, f.RawInvalid, f.LocalFlags, f.NoPermissions, f.Platform, f.InodeChangeTime()) case FileInfoTypeFile: return fmt.Sprintf("File{Name:%q, Sequence:%d, Permissions:0%o, ModTime:%v, Version:%v, VersionHash:%x, Length:%d, Deleted:%v, Invalid:%v, LocalFlags:0x%x, NoPermissions:%v, BlockSize:%d, NumBlocks:%d, BlocksHash:%x, Platform:%v, InodeChangeTime:%v}", f.Name, f.Sequence, f.Permissions, f.ModTime(), f.Version, f.VersionHash, f.Size, f.Deleted, f.RawInvalid, f.LocalFlags, f.NoPermissions, f.RawBlockSize, len(f.Blocks), f.BlocksHash, f.Platform, f.InodeChangeTime()) case FileInfoTypeSymlink, FileInfoTypeSymlinkDirectory, FileInfoTypeSymlinkFile: return fmt.Sprintf("Symlink{Name:%q, Type:%v, Sequence:%d, Version:%v, VersionHash:%x, Deleted:%v, Invalid:%v, LocalFlags:0x%x, NoPermissions:%v, SymlinkTarget:%q, Platform:%v, InodeChangeTime:%v}", f.Name, f.Type, f.Sequence, f.Version, f.VersionHash, f.Deleted, f.RawInvalid, f.LocalFlags, f.NoPermissions, f.SymlinkTarget, f.Platform, f.InodeChangeTime()) default: panic("mystery file type detected") } } func (f FileInfo) IsDeleted() bool { return f.Deleted } func (f FileInfo) IsInvalid() bool { return f.RawInvalid || f.LocalFlags&LocalInvalidFlags != 0 } func (f FileInfo) IsUnsupported() bool { return f.LocalFlags&FlagLocalUnsupported != 0 } func (f FileInfo) IsIgnored() bool { return f.LocalFlags&FlagLocalIgnored != 0 } func (f FileInfo) MustRescan() bool { return f.LocalFlags&FlagLocalMustRescan != 0 } func (f FileInfo) IsReceiveOnlyChanged() bool { return f.LocalFlags&FlagLocalReceiveOnly != 0 } func (f FileInfo) IsDirectory() bool { return f.Type == FileInfoTypeDirectory } func (f FileInfo) ShouldConflict() bool { return f.LocalFlags&LocalConflictFlags != 0 } func (f FileInfo) IsSymlink() bool { switch f.Type { case FileInfoTypeSymlink, FileInfoTypeSymlinkDirectory, FileInfoTypeSymlinkFile: return true default: return false } } func (f FileInfo) HasPermissionBits() bool { return !f.NoPermissions } func (f FileInfo) FileSize() int64 { if f.Deleted { return 0 } if f.IsDirectory() || f.IsSymlink() { return SyntheticDirectorySize } return f.Size } func (f FileInfo) BlockSize() int { if f.RawBlockSize < MinBlockSize { return MinBlockSize } return f.RawBlockSize } func (f FileInfo) FileName() string { return f.Name } func (f FileInfo) FileLocalFlags() uint32 { return f.LocalFlags } func (f FileInfo) ModTime() time.Time { return time.Unix(f.ModifiedS, int64(f.ModifiedNs)) } func (f FileInfo) SequenceNo() int64 { return f.Sequence } func (f FileInfo) FileVersion() Vector { return f.Version } func (f FileInfo) FileType() FileInfoType { return f.Type } func (f FileInfo) FilePermissions() uint32 { return f.Permissions } func (f FileInfo) FileModifiedBy() ShortID { return f.ModifiedBy } func (f FileInfo) PlatformData() PlatformData { return f.Platform } func (f FileInfo) InodeChangeTime() time.Time { return time.Unix(0, f.InodeChangeNs) } func (f FileInfo) FileBlocksHash() []byte { return f.BlocksHash } // WinsConflict returns true if "f" is the one to choose when it is in // conflict with "other". func WinsConflict(f, other FileIntf) bool { // If only one of the files is invalid, that one loses. if f.IsInvalid() != other.IsInvalid() { return !f.IsInvalid() } // If a modification is in conflict with a delete, we pick the // modification. if !f.IsDeleted() && other.IsDeleted() { return true } if f.IsDeleted() && !other.IsDeleted() { return false } // The one with the newer modification time wins. if f.ModTime().After(other.ModTime()) { return true } if f.ModTime().Before(other.ModTime()) { return false } // The modification times were equal. Use the device ID in the version // vector as tie breaker. return f.FileVersion().Compare(other.FileVersion()) == ConcurrentGreater } type FileInfoComparison struct { ModTimeWindow time.Duration IgnorePerms bool IgnoreBlocks bool IgnoreFlags uint32 IgnoreOwnership bool IgnoreXattrs bool } func (f FileInfo) IsEquivalent(other FileInfo, modTimeWindow time.Duration) bool { return f.isEquivalent(other, FileInfoComparison{ModTimeWindow: modTimeWindow}) } func (f FileInfo) IsEquivalentOptional(other FileInfo, comp FileInfoComparison) bool { return f.isEquivalent(other, comp) } // isEquivalent checks that the two file infos represent the same actual file content, // i.e. it does purposely not check only selected (see below) struct members. // Permissions (config) and blocks (scanning) can be excluded from the comparison. // Any file info is not "equivalent", if it has different // - type // - deleted flag // - invalid flag // - permissions, unless they are ignored // // A file is not "equivalent", if it has different // - modification time (difference bigger than modTimeWindow) // - size // - blocks, unless there are no blocks to compare (scanning) // - os data // // A symlink is not "equivalent", if it has different // - target // // A directory does not have anything specific to check. func (f FileInfo) isEquivalent(other FileInfo, comp FileInfoComparison) bool { if f.MustRescan() || other.MustRescan() { // These are per definition not equivalent because they don't // represent a valid state, even if both happen to have the // MustRescan bit set. return false } // If we care about either ownership or xattrs, are recording inode change // times and it changed, they are not equal. if !(comp.IgnoreOwnership && comp.IgnoreXattrs) && f.InodeChangeNs != 0 && other.InodeChangeNs != 0 && f.InodeChangeNs != other.InodeChangeNs { return false } // Mask out the ignored local flags before checking IsInvalid() below f.LocalFlags &^= comp.IgnoreFlags other.LocalFlags &^= comp.IgnoreFlags if f.Name != other.Name || f.Type != other.Type || f.Deleted != other.Deleted || f.IsInvalid() != other.IsInvalid() { return false } if !comp.IgnoreOwnership && f.Platform != other.Platform { if !unixOwnershipEqual(f.Platform.Unix, other.Platform.Unix) { return false } if !windowsOwnershipEqual(f.Platform.Windows, other.Platform.Windows) { return false } } if !comp.IgnoreXattrs && f.Platform != other.Platform { if !xattrsEqual(f.Platform.Linux, other.Platform.Linux) { return false } if !xattrsEqual(f.Platform.Darwin, other.Platform.Darwin) { return false } if !xattrsEqual(f.Platform.FreeBSD, other.Platform.FreeBSD) { return false } if !xattrsEqual(f.Platform.NetBSD, other.Platform.NetBSD) { return false } } if !comp.IgnorePerms && !f.NoPermissions && !other.NoPermissions && !PermsEqual(f.Permissions, other.Permissions) { return false } switch f.Type { case FileInfoTypeFile: return f.Size == other.Size && ModTimeEqual(f.ModTime(), other.ModTime(), comp.ModTimeWindow) && (comp.IgnoreBlocks || f.BlocksEqual(other)) case FileInfoTypeSymlink: return f.SymlinkTarget == other.SymlinkTarget case FileInfoTypeDirectory: return true } return false } func ModTimeEqual(a, b time.Time, modTimeWindow time.Duration) bool { if a.Equal(b) { return true } diff := a.Sub(b) if diff < 0 { diff *= -1 } return diff < modTimeWindow } func PermsEqual(a, b uint32) bool { if build.IsWindows { // There is only writeable and read only, represented for user, group // and other equally. We only compare against user. return a&0600 == b&0600 } // All bits count return a&0777 == b&0777 } // BlocksEqual returns true when the two files have identical block lists. func (f FileInfo) BlocksEqual(other FileInfo) bool { // If both sides have blocks hashes and they match, we are good. If they // don't match still check individual block hashes to catch differences // in weak hashes only (e.g. after switching weak hash algo). if len(f.BlocksHash) > 0 && len(other.BlocksHash) > 0 && bytes.Equal(f.BlocksHash, other.BlocksHash) { return true } // Actually compare the block lists in full. return blocksEqual(f.Blocks, other.Blocks) } // Xattrs is a convenience method to return the extended attributes of the // file for the current platform. func (f *PlatformData) Xattrs() []Xattr { switch { case build.IsLinux && f.Linux != nil: return f.Linux.Xattrs case build.IsDarwin && f.Darwin != nil: return f.Darwin.Xattrs case build.IsFreeBSD && f.FreeBSD != nil: return f.FreeBSD.Xattrs case build.IsNetBSD && f.NetBSD != nil: return f.NetBSD.Xattrs default: return nil } } // SetXattrs is a convenience method to set the extended attributes of the // file for the current platform. func (p *PlatformData) SetXattrs(xattrs []Xattr) { switch { case build.IsLinux: if p.Linux == nil { p.Linux = &XattrData{} } p.Linux.Xattrs = xattrs case build.IsDarwin: if p.Darwin == nil { p.Darwin = &XattrData{} } p.Darwin.Xattrs = xattrs case build.IsFreeBSD: if p.FreeBSD == nil { p.FreeBSD = &XattrData{} } p.FreeBSD.Xattrs = xattrs case build.IsNetBSD: if p.NetBSD == nil { p.NetBSD = &XattrData{} } p.NetBSD.Xattrs = xattrs } } // MergeWith copies platform data from other, for platforms where it's not // already set on p. func (p *PlatformData) MergeWith(other *PlatformData) { if p.Unix == nil { p.Unix = other.Unix } if p.Windows == nil { p.Windows = other.Windows } if p.Linux == nil { p.Linux = other.Linux } if p.Darwin == nil { p.Darwin = other.Darwin } if p.FreeBSD == nil { p.FreeBSD = other.FreeBSD } if p.NetBSD == nil { p.NetBSD = other.NetBSD } } // blocksEqual returns whether two slices of blocks are exactly the same hash // and index pair wise. func blocksEqual(a, b []BlockInfo) bool { if len(b) != len(a) { return false } for i, sblk := range a { if !bytes.Equal(sblk.Hash, b[i].Hash) { return false } } return true } func (f *FileInfo) SetMustRescan() { f.setLocalFlags(FlagLocalMustRescan) } func (f *FileInfo) SetIgnored() { f.setLocalFlags(FlagLocalIgnored) } func (f *FileInfo) SetUnsupported() { f.setLocalFlags(FlagLocalUnsupported) } func (f *FileInfo) SetDeleted(by ShortID) { f.ModifiedBy = by f.Deleted = true f.Version = f.Version.Update(by) f.ModifiedS = time.Now().Unix() f.setNoContent() } func (f *FileInfo) setLocalFlags(flags uint32) { f.RawInvalid = false f.LocalFlags = flags f.setNoContent() } func (f *FileInfo) setNoContent() { f.Blocks = nil f.BlocksHash = nil f.Size = 0 } func (b BlockInfo) String() string { return fmt.Sprintf("Block{%d/%d/%d/%x}", b.Offset, b.Size, b.WeakHash, b.Hash) } // IsEmpty returns true if the block is a full block of zeroes. func (b BlockInfo) IsEmpty() bool { if v, ok := sha256OfEmptyBlock[int(b.Size)]; ok { return bytes.Equal(b.Hash, v[:]) } return false } type IndexID uint64 func (i IndexID) String() string { return fmt.Sprintf("0x%016X", uint64(i)) } func (i IndexID) Marshal() ([]byte, error) { bs := make([]byte, 8) binary.BigEndian.PutUint64(bs, uint64(i)) return bs, nil } func (i *IndexID) Unmarshal(bs []byte) error { if len(bs) != 8 { return errors.New("incorrect IndexID length") } *i = IndexID(binary.BigEndian.Uint64(bs)) return nil } func NewIndexID() IndexID { return IndexID(rand.Uint64()) } func (f Folder) Description() string { // used by logging stuff if f.Label == "" { return f.ID } return fmt.Sprintf("%q (%s)", f.Label, f.ID) } func BlocksHash(bs []BlockInfo) []byte { h := sha256.New() for _, b := range bs { _, _ = h.Write(b.Hash) _ = binary.Write(h, binary.BigEndian, b.WeakHash) } return h.Sum(nil) } func VectorHash(v Vector) []byte { h := sha256.New() for _, c := range v.Counters { if err := binary.Write(h, binary.BigEndian, c.ID); err != nil { panic("impossible: failed to write c.ID to hash function: " + err.Error()) } if err := binary.Write(h, binary.BigEndian, c.Value); err != nil { panic("impossible: failed to write c.Value to hash function: " + err.Error()) } } return h.Sum(nil) } func (x *FileInfoType) MarshalJSON() ([]byte, error) { return json.Marshal(x.String()) } func (x *FileInfoType) UnmarshalJSON(data []byte) error { var s string if err := json.Unmarshal(data, &s); err != nil { return err } n, ok := FileInfoType_value[s] if !ok { return errors.New("invalid value: " + s) } *x = FileInfoType(n) return nil } func xattrsEqual(a, b *XattrData) bool { aEmpty := a == nil || len(a.Xattrs) == 0 bEmpty := b == nil || len(b.Xattrs) == 0 if aEmpty && bEmpty { return true } if aEmpty || bEmpty { // Only one side is empty, so they can't be equal. return false } if len(a.Xattrs) != len(b.Xattrs) { return false } for i := range a.Xattrs { if a.Xattrs[i].Name != b.Xattrs[i].Name { return false } if !bytes.Equal(a.Xattrs[i].Value, b.Xattrs[i].Value) { return false } } return true } func unixOwnershipEqual(a, b *UnixData) bool { if a == nil && b == nil { return true } if a == nil || b == nil { return false } ownerEqual := a.OwnerName == "" || b.OwnerName == "" || a.OwnerName == b.OwnerName groupEqual := a.GroupName == "" || b.GroupName == "" || a.GroupName == b.GroupName return a.UID == b.UID && a.GID == b.GID && ownerEqual && groupEqual } func windowsOwnershipEqual(a, b *WindowsData) bool { if a == nil && b == nil { return true } if a == nil || b == nil { return false } return a.OwnerName == b.OwnerName && a.OwnerIsGroup == b.OwnerIsGroup }