package sftp // ssh_FXP_ATTRS support // see http://tools.ietf.org/html/draft-ietf-secsh-filexfer-02#section-5 import ( "os" "syscall" "time" ) const ( ssh_FILEXFER_ATTR_SIZE = 0x00000001 ssh_FILEXFER_ATTR_UIDGID = 0x00000002 ssh_FILEXFER_ATTR_PERMISSIONS = 0x00000004 ssh_FILEXFER_ATTR_ACMODTIME = 0x00000008 ssh_FILEXFER_ATTR_EXTENDED = 0x80000000 ) // fileInfo is an artificial type designed to satisfy os.FileInfo. type fileInfo struct { name string size int64 mode os.FileMode mtime time.Time sys interface{} } // Name returns the base name of the file. func (fi *fileInfo) Name() string { return fi.name } // Size returns the length in bytes for regular files; system-dependent for others. func (fi *fileInfo) Size() int64 { return fi.size } // Mode returns file mode bits. func (fi *fileInfo) Mode() os.FileMode { return fi.mode } // ModTime returns the last modification time of the file. func (fi *fileInfo) ModTime() time.Time { return fi.mtime } // IsDir returns true if the file is a directory. func (fi *fileInfo) IsDir() bool { return fi.Mode().IsDir() } func (fi *fileInfo) Sys() interface{} { return fi.sys } // FileStat holds the original unmarshalled values from a call to READDIR or *STAT. // It is exported for the purposes of accessing the raw values via os.FileInfo.Sys() type FileStat struct { Size uint64 Mode uint32 Mtime uint32 Atime uint32 UID uint32 GID uint32 Extended []StatExtended } // StatExtended contains additional, extended information for a FileStat. type StatExtended struct { ExtType string ExtData string } func fileInfoFromStat(st *FileStat, name string) os.FileInfo { fs := &fileInfo{ name: name, size: int64(st.Size), mode: toFileMode(st.Mode), mtime: time.Unix(int64(st.Mtime), 0), sys: st, } return fs } func fileStatFromInfo(fi os.FileInfo) (uint32, FileStat) { mtime := fi.ModTime().Unix() atime := mtime var flags uint32 = ssh_FILEXFER_ATTR_SIZE | ssh_FILEXFER_ATTR_PERMISSIONS | ssh_FILEXFER_ATTR_ACMODTIME fileStat := FileStat{ Size: uint64(fi.Size()), Mode: fromFileMode(fi.Mode()), Mtime: uint32(mtime), Atime: uint32(atime), } // os specific file stat decoding fileStatFromInfoOs(fi, &flags, &fileStat) return flags, fileStat } func unmarshalAttrs(b []byte) (*FileStat, []byte) { flags, b := unmarshalUint32(b) return getFileStat(flags, b) } func getFileStat(flags uint32, b []byte) (*FileStat, []byte) { var fs FileStat if flags&ssh_FILEXFER_ATTR_SIZE == ssh_FILEXFER_ATTR_SIZE { fs.Size, b = unmarshalUint64(b) } if flags&ssh_FILEXFER_ATTR_UIDGID == ssh_FILEXFER_ATTR_UIDGID { fs.UID, b = unmarshalUint32(b) } if flags&ssh_FILEXFER_ATTR_UIDGID == ssh_FILEXFER_ATTR_UIDGID { fs.GID, b = unmarshalUint32(b) } if flags&ssh_FILEXFER_ATTR_PERMISSIONS == ssh_FILEXFER_ATTR_PERMISSIONS { fs.Mode, b = unmarshalUint32(b) } if flags&ssh_FILEXFER_ATTR_ACMODTIME == ssh_FILEXFER_ATTR_ACMODTIME { fs.Atime, b = unmarshalUint32(b) fs.Mtime, b = unmarshalUint32(b) } if flags&ssh_FILEXFER_ATTR_EXTENDED == ssh_FILEXFER_ATTR_EXTENDED { var count uint32 count, b = unmarshalUint32(b) ext := make([]StatExtended, count, count) for i := uint32(0); i < count; i++ { var typ string var data string typ, b = unmarshalString(b) data, b = unmarshalString(b) ext[i] = StatExtended{typ, data} } fs.Extended = ext } return &fs, b } func marshalFileInfo(b []byte, fi os.FileInfo) []byte { // attributes variable struct, and also variable per protocol version // spec version 3 attributes: // uint32 flags // uint64 size present only if flag SSH_FILEXFER_ATTR_SIZE // uint32 uid present only if flag SSH_FILEXFER_ATTR_UIDGID // uint32 gid present only if flag SSH_FILEXFER_ATTR_UIDGID // uint32 permissions present only if flag SSH_FILEXFER_ATTR_PERMISSIONS // uint32 atime present only if flag SSH_FILEXFER_ACMODTIME // uint32 mtime present only if flag SSH_FILEXFER_ACMODTIME // uint32 extended_count present only if flag SSH_FILEXFER_ATTR_EXTENDED // string extended_type // string extended_data // ... more extended data (extended_type - extended_data pairs), // so that number of pairs equals extended_count flags, fileStat := fileStatFromInfo(fi) b = marshalUint32(b, flags) if flags&ssh_FILEXFER_ATTR_SIZE != 0 { b = marshalUint64(b, fileStat.Size) } if flags&ssh_FILEXFER_ATTR_UIDGID != 0 { b = marshalUint32(b, fileStat.UID) b = marshalUint32(b, fileStat.GID) } if flags&ssh_FILEXFER_ATTR_PERMISSIONS != 0 { b = marshalUint32(b, fileStat.Mode) } if flags&ssh_FILEXFER_ATTR_ACMODTIME != 0 { b = marshalUint32(b, fileStat.Atime) b = marshalUint32(b, fileStat.Mtime) } return b } // toFileMode converts sftp filemode bits to the os.FileMode specification func toFileMode(mode uint32) os.FileMode { var fm = os.FileMode(mode & 0777) switch mode & syscall.S_IFMT { case syscall.S_IFBLK: fm |= os.ModeDevice case syscall.S_IFCHR: fm |= os.ModeDevice | os.ModeCharDevice case syscall.S_IFDIR: fm |= os.ModeDir case syscall.S_IFIFO: fm |= os.ModeNamedPipe case syscall.S_IFLNK: fm |= os.ModeSymlink case syscall.S_IFREG: // nothing to do case syscall.S_IFSOCK: fm |= os.ModeSocket } if mode&syscall.S_ISGID != 0 { fm |= os.ModeSetgid } if mode&syscall.S_ISUID != 0 { fm |= os.ModeSetuid } if mode&syscall.S_ISVTX != 0 { fm |= os.ModeSticky } return fm } // fromFileMode converts from the os.FileMode specification to sftp filemode bits func fromFileMode(mode os.FileMode) uint32 { ret := uint32(0) if mode&os.ModeDevice != 0 { if mode&os.ModeCharDevice != 0 { ret |= syscall.S_IFCHR } else { ret |= syscall.S_IFBLK } } if mode&os.ModeDir != 0 { ret |= syscall.S_IFDIR } if mode&os.ModeSymlink != 0 { ret |= syscall.S_IFLNK } if mode&os.ModeNamedPipe != 0 { ret |= syscall.S_IFIFO } if mode&os.ModeSetgid != 0 { ret |= syscall.S_ISGID } if mode&os.ModeSetuid != 0 { ret |= syscall.S_ISUID } if mode&os.ModeSticky != 0 { ret |= syscall.S_ISVTX } if mode&os.ModeSocket != 0 { ret |= syscall.S_IFSOCK } if mode&os.ModeType == 0 { ret |= syscall.S_IFREG } ret |= uint32(mode & os.ModePerm) return ret }