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author | Wim <wim@42.be> | 2018-03-04 23:46:13 +0100 |
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committer | Wim <wim@42.be> | 2018-03-04 23:46:13 +0100 |
commit | 25a72113b122f984c904b24c4af23a1cba1eff45 (patch) | |
tree | f0fb7067d7c958d60ac964afa5b8d5fb79ebc339 /vendor/github.com/pkg/sftp/server.go | |
parent | 79c4ad5015bd2be47b32141c6d53f0d128bf865b (diff) | |
download | matterbridge-msglm-25a72113b122f984c904b24c4af23a1cba1eff45.tar.gz matterbridge-msglm-25a72113b122f984c904b24c4af23a1cba1eff45.tar.bz2 matterbridge-msglm-25a72113b122f984c904b24c4af23a1cba1eff45.zip |
Add vendor files for spf13/viper
Diffstat (limited to 'vendor/github.com/pkg/sftp/server.go')
-rw-r--r-- | vendor/github.com/pkg/sftp/server.go | 675 |
1 files changed, 675 insertions, 0 deletions
diff --git a/vendor/github.com/pkg/sftp/server.go b/vendor/github.com/pkg/sftp/server.go new file mode 100644 index 00000000..16678d1f --- /dev/null +++ b/vendor/github.com/pkg/sftp/server.go @@ -0,0 +1,675 @@ +package sftp + +// sftp server counterpart + +import ( + "encoding" + "fmt" + "io" + "io/ioutil" + "os" + "path/filepath" + "strconv" + "sync" + "syscall" + "time" + + "github.com/pkg/errors" +) + +const ( + SftpServerWorkerCount = 8 +) + +// Server is an SSH File Transfer Protocol (sftp) server. +// This is intended to provide the sftp subsystem to an ssh server daemon. +// This implementation currently supports most of sftp server protocol version 3, +// as specified at http://tools.ietf.org/html/draft-ietf-secsh-filexfer-02 +type Server struct { + *serverConn + debugStream io.Writer + readOnly bool + pktMgr *packetManager + openFiles map[string]*os.File + openFilesLock sync.RWMutex + handleCount int + maxTxPacket uint32 +} + +func (svr *Server) nextHandle(f *os.File) string { + svr.openFilesLock.Lock() + defer svr.openFilesLock.Unlock() + svr.handleCount++ + handle := strconv.Itoa(svr.handleCount) + svr.openFiles[handle] = f + return handle +} + +func (svr *Server) closeHandle(handle string) error { + svr.openFilesLock.Lock() + defer svr.openFilesLock.Unlock() + if f, ok := svr.openFiles[handle]; ok { + delete(svr.openFiles, handle) + return f.Close() + } + + return syscall.EBADF +} + +func (svr *Server) getHandle(handle string) (*os.File, bool) { + svr.openFilesLock.RLock() + defer svr.openFilesLock.RUnlock() + f, ok := svr.openFiles[handle] + return f, ok +} + +type serverRespondablePacket interface { + encoding.BinaryUnmarshaler + id() uint32 + respond(svr *Server) error +} + +// NewServer creates a new Server instance around the provided streams, serving +// content from the root of the filesystem. Optionally, ServerOption +// functions may be specified to further configure the Server. +// +// A subsequent call to Serve() is required to begin serving files over SFTP. +func NewServer(rwc io.ReadWriteCloser, options ...ServerOption) (*Server, error) { + svrConn := &serverConn{ + conn: conn{ + Reader: rwc, + WriteCloser: rwc, + }, + } + s := &Server{ + serverConn: svrConn, + debugStream: ioutil.Discard, + pktMgr: newPktMgr(svrConn), + openFiles: make(map[string]*os.File), + maxTxPacket: 1 << 15, + } + + for _, o := range options { + if err := o(s); err != nil { + return nil, err + } + } + + return s, nil +} + +// A ServerOption is a function which applies configuration to a Server. +type ServerOption func(*Server) error + +// WithDebug enables Server debugging output to the supplied io.Writer. +func WithDebug(w io.Writer) ServerOption { + return func(s *Server) error { + s.debugStream = w + return nil + } +} + +// ReadOnly configures a Server to serve files in read-only mode. +func ReadOnly() ServerOption { + return func(s *Server) error { + s.readOnly = true + return nil + } +} + +type rxPacket struct { + pktType fxp + pktBytes []byte +} + +// Up to N parallel servers +func (svr *Server) sftpServerWorker(pktChan chan requestPacket) error { + for pkt := range pktChan { + + // readonly checks + readonly := true + switch pkt := pkt.(type) { + case notReadOnly: + readonly = false + case *sshFxpOpenPacket: + readonly = pkt.readonly() + case *sshFxpExtendedPacket: + readonly = pkt.SpecificPacket.readonly() + } + + // If server is operating read-only and a write operation is requested, + // return permission denied + if !readonly && svr.readOnly { + if err := svr.sendError(pkt, syscall.EPERM); err != nil { + return errors.Wrap(err, "failed to send read only packet response") + } + continue + } + + if err := handlePacket(svr, pkt); err != nil { + return err + } + } + return nil +} + +func handlePacket(s *Server, p interface{}) error { + switch p := p.(type) { + case *sshFxInitPacket: + return s.sendPacket(sshFxVersionPacket{sftpProtocolVersion, nil}) + case *sshFxpStatPacket: + // stat the requested file + info, err := os.Stat(p.Path) + if err != nil { + return s.sendError(p, err) + } + return s.sendPacket(sshFxpStatResponse{ + ID: p.ID, + info: info, + }) + case *sshFxpLstatPacket: + // stat the requested file + info, err := os.Lstat(p.Path) + if err != nil { + return s.sendError(p, err) + } + return s.sendPacket(sshFxpStatResponse{ + ID: p.ID, + info: info, + }) + case *sshFxpFstatPacket: + f, ok := s.getHandle(p.Handle) + if !ok { + return s.sendError(p, syscall.EBADF) + } + + info, err := f.Stat() + if err != nil { + return s.sendError(p, err) + } + + return s.sendPacket(sshFxpStatResponse{ + ID: p.ID, + info: info, + }) + case *sshFxpMkdirPacket: + // TODO FIXME: ignore flags field + err := os.Mkdir(p.Path, 0755) + return s.sendError(p, err) + case *sshFxpRmdirPacket: + err := os.Remove(p.Path) + return s.sendError(p, err) + case *sshFxpRemovePacket: + err := os.Remove(p.Filename) + return s.sendError(p, err) + case *sshFxpRenamePacket: + err := os.Rename(p.Oldpath, p.Newpath) + return s.sendError(p, err) + case *sshFxpSymlinkPacket: + err := os.Symlink(p.Targetpath, p.Linkpath) + return s.sendError(p, err) + case *sshFxpClosePacket: + return s.sendError(p, s.closeHandle(p.Handle)) + case *sshFxpReadlinkPacket: + f, err := os.Readlink(p.Path) + if err != nil { + return s.sendError(p, err) + } + + return s.sendPacket(sshFxpNamePacket{ + ID: p.ID, + NameAttrs: []sshFxpNameAttr{{ + Name: f, + LongName: f, + Attrs: emptyFileStat, + }}, + }) + + case *sshFxpRealpathPacket: + f, err := filepath.Abs(p.Path) + if err != nil { + return s.sendError(p, err) + } + f = cleanPath(f) + return s.sendPacket(sshFxpNamePacket{ + ID: p.ID, + NameAttrs: []sshFxpNameAttr{{ + Name: f, + LongName: f, + Attrs: emptyFileStat, + }}, + }) + case *sshFxpOpendirPacket: + return sshFxpOpenPacket{ + ID: p.ID, + Path: p.Path, + Pflags: ssh_FXF_READ, + }.respond(s) + case *sshFxpReadPacket: + f, ok := s.getHandle(p.Handle) + if !ok { + return s.sendError(p, syscall.EBADF) + } + + data := make([]byte, clamp(p.Len, s.maxTxPacket)) + n, err := f.ReadAt(data, int64(p.Offset)) + if err != nil && (err != io.EOF || n == 0) { + return s.sendError(p, err) + } + return s.sendPacket(sshFxpDataPacket{ + ID: p.ID, + Length: uint32(n), + Data: data[:n], + }) + case *sshFxpWritePacket: + f, ok := s.getHandle(p.Handle) + if !ok { + return s.sendError(p, syscall.EBADF) + } + + _, err := f.WriteAt(p.Data, int64(p.Offset)) + return s.sendError(p, err) + case serverRespondablePacket: + err := p.respond(s) + return errors.Wrap(err, "pkt.respond failed") + default: + return errors.Errorf("unexpected packet type %T", p) + } +} + +// Serve serves SFTP connections until the streams stop or the SFTP subsystem +// is stopped. +func (svr *Server) Serve() error { + var wg sync.WaitGroup + runWorker := func(ch requestChan) { + wg.Add(1) + go func() { + defer wg.Done() + if err := svr.sftpServerWorker(ch); err != nil { + svr.conn.Close() // shuts down recvPacket + } + }() + } + pktChan := svr.pktMgr.workerChan(runWorker) + + var err error + var pkt requestPacket + var pktType uint8 + var pktBytes []byte + for { + pktType, pktBytes, err = svr.recvPacket() + if err != nil { + break + } + + pkt, err = makePacket(rxPacket{fxp(pktType), pktBytes}) + if err != nil { + debug("makePacket err: %v", err) + svr.conn.Close() // shuts down recvPacket + break + } + + pktChan <- pkt + } + + close(pktChan) // shuts down sftpServerWorkers + wg.Wait() // wait for all workers to exit + + // close any still-open files + for handle, file := range svr.openFiles { + fmt.Fprintf(svr.debugStream, "sftp server file with handle %q left open: %v\n", handle, file.Name()) + file.Close() + } + return err // error from recvPacket +} + +// Wrap underlying connection methods to use packetManager +func (svr *Server) sendPacket(m encoding.BinaryMarshaler) error { + if pkt, ok := m.(responsePacket); ok { + svr.pktMgr.readyPacket(pkt) + } else { + return errors.Errorf("unexpected packet type %T", m) + } + return nil +} + +func (svr *Server) sendError(p ider, err error) error { + return svr.sendPacket(statusFromError(p, err)) +} + +type ider interface { + id() uint32 +} + +// The init packet has no ID, so we just return a zero-value ID +func (p sshFxInitPacket) id() uint32 { return 0 } + +type sshFxpStatResponse struct { + ID uint32 + info os.FileInfo +} + +func (p sshFxpStatResponse) MarshalBinary() ([]byte, error) { + b := []byte{ssh_FXP_ATTRS} + b = marshalUint32(b, p.ID) + b = marshalFileInfo(b, p.info) + return b, nil +} + +var emptyFileStat = []interface{}{uint32(0)} + +func (p sshFxpOpenPacket) readonly() bool { + return !p.hasPflags(ssh_FXF_WRITE) +} + +func (p sshFxpOpenPacket) hasPflags(flags ...uint32) bool { + for _, f := range flags { + if p.Pflags&f == 0 { + return false + } + } + return true +} + +func (p sshFxpOpenPacket) respond(svr *Server) error { + var osFlags int + if p.hasPflags(ssh_FXF_READ, ssh_FXF_WRITE) { + osFlags |= os.O_RDWR + } else if p.hasPflags(ssh_FXF_WRITE) { + osFlags |= os.O_WRONLY + } else if p.hasPflags(ssh_FXF_READ) { + osFlags |= os.O_RDONLY + } else { + // how are they opening? + return svr.sendError(p, syscall.EINVAL) + } + + if p.hasPflags(ssh_FXF_APPEND) { + osFlags |= os.O_APPEND + } + if p.hasPflags(ssh_FXF_CREAT) { + osFlags |= os.O_CREATE + } + if p.hasPflags(ssh_FXF_TRUNC) { + osFlags |= os.O_TRUNC + } + if p.hasPflags(ssh_FXF_EXCL) { + osFlags |= os.O_EXCL + } + + f, err := os.OpenFile(p.Path, osFlags, 0644) + if err != nil { + return svr.sendError(p, err) + } + + handle := svr.nextHandle(f) + return svr.sendPacket(sshFxpHandlePacket{p.ID, handle}) +} + +func (p sshFxpReaddirPacket) respond(svr *Server) error { + f, ok := svr.getHandle(p.Handle) + if !ok { + return svr.sendError(p, syscall.EBADF) + } + + dirname := f.Name() + dirents, err := f.Readdir(128) + if err != nil { + return svr.sendError(p, err) + } + + ret := sshFxpNamePacket{ID: p.ID} + for _, dirent := range dirents { + ret.NameAttrs = append(ret.NameAttrs, sshFxpNameAttr{ + Name: dirent.Name(), + LongName: runLs(dirname, dirent), + Attrs: []interface{}{dirent}, + }) + } + return svr.sendPacket(ret) +} + +func (p sshFxpSetstatPacket) respond(svr *Server) error { + // additional unmarshalling is required for each possibility here + b := p.Attrs.([]byte) + var err error + + debug("setstat name \"%s\"", p.Path) + if (p.Flags & ssh_FILEXFER_ATTR_SIZE) != 0 { + var size uint64 + if size, b, err = unmarshalUint64Safe(b); err == nil { + err = os.Truncate(p.Path, int64(size)) + } + } + if (p.Flags & ssh_FILEXFER_ATTR_PERMISSIONS) != 0 { + var mode uint32 + if mode, b, err = unmarshalUint32Safe(b); err == nil { + err = os.Chmod(p.Path, os.FileMode(mode)) + } + } + if (p.Flags & ssh_FILEXFER_ATTR_ACMODTIME) != 0 { + var atime uint32 + var mtime uint32 + if atime, b, err = unmarshalUint32Safe(b); err != nil { + } else if mtime, b, err = unmarshalUint32Safe(b); err != nil { + } else { + atimeT := time.Unix(int64(atime), 0) + mtimeT := time.Unix(int64(mtime), 0) + err = os.Chtimes(p.Path, atimeT, mtimeT) + } + } + if (p.Flags & ssh_FILEXFER_ATTR_UIDGID) != 0 { + var uid uint32 + var gid uint32 + if uid, b, err = unmarshalUint32Safe(b); err != nil { + } else if gid, _, err = unmarshalUint32Safe(b); err != nil { + } else { + err = os.Chown(p.Path, int(uid), int(gid)) + } + } + + return svr.sendError(p, err) +} + +func (p sshFxpFsetstatPacket) respond(svr *Server) error { + f, ok := svr.getHandle(p.Handle) + if !ok { + return svr.sendError(p, syscall.EBADF) + } + + // additional unmarshalling is required for each possibility here + b := p.Attrs.([]byte) + var err error + + debug("fsetstat name \"%s\"", f.Name()) + if (p.Flags & ssh_FILEXFER_ATTR_SIZE) != 0 { + var size uint64 + if size, b, err = unmarshalUint64Safe(b); err == nil { + err = f.Truncate(int64(size)) + } + } + if (p.Flags & ssh_FILEXFER_ATTR_PERMISSIONS) != 0 { + var mode uint32 + if mode, b, err = unmarshalUint32Safe(b); err == nil { + err = f.Chmod(os.FileMode(mode)) + } + } + if (p.Flags & ssh_FILEXFER_ATTR_ACMODTIME) != 0 { + var atime uint32 + var mtime uint32 + if atime, b, err = unmarshalUint32Safe(b); err != nil { + } else if mtime, b, err = unmarshalUint32Safe(b); err != nil { + } else { + atimeT := time.Unix(int64(atime), 0) + mtimeT := time.Unix(int64(mtime), 0) + err = os.Chtimes(f.Name(), atimeT, mtimeT) + } + } + if (p.Flags & ssh_FILEXFER_ATTR_UIDGID) != 0 { + var uid uint32 + var gid uint32 + if uid, b, err = unmarshalUint32Safe(b); err != nil { + } else if gid, _, err = unmarshalUint32Safe(b); err != nil { + } else { + err = f.Chown(int(uid), int(gid)) + } + } + + return svr.sendError(p, err) +} + +// translateErrno translates a syscall error number to a SFTP error code. +func translateErrno(errno syscall.Errno) uint32 { + switch errno { + case 0: + return ssh_FX_OK + case syscall.ENOENT: + return ssh_FX_NO_SUCH_FILE + case syscall.EPERM: + return ssh_FX_PERMISSION_DENIED + } + + return ssh_FX_FAILURE +} + +func statusFromError(p ider, err error) sshFxpStatusPacket { + ret := sshFxpStatusPacket{ + ID: p.id(), + StatusError: StatusError{ + // ssh_FX_OK = 0 + // ssh_FX_EOF = 1 + // ssh_FX_NO_SUCH_FILE = 2 ENOENT + // ssh_FX_PERMISSION_DENIED = 3 + // ssh_FX_FAILURE = 4 + // ssh_FX_BAD_MESSAGE = 5 + // ssh_FX_NO_CONNECTION = 6 + // ssh_FX_CONNECTION_LOST = 7 + // ssh_FX_OP_UNSUPPORTED = 8 + Code: ssh_FX_OK, + }, + } + if err == nil { + return ret + } + + debug("statusFromError: error is %T %#v", err, err) + ret.StatusError.Code = ssh_FX_FAILURE + ret.StatusError.msg = err.Error() + + switch e := err.(type) { + case syscall.Errno: + ret.StatusError.Code = translateErrno(e) + case *os.PathError: + debug("statusFromError,pathError: error is %T %#v", e.Err, e.Err) + if errno, ok := e.Err.(syscall.Errno); ok { + ret.StatusError.Code = translateErrno(errno) + } + case fxerr: + ret.StatusError.Code = uint32(e) + default: + switch e { + case io.EOF: + ret.StatusError.Code = ssh_FX_EOF + case os.ErrNotExist: + ret.StatusError.Code = ssh_FX_NO_SUCH_FILE + } + } + + return ret +} + +func clamp(v, max uint32) uint32 { + if v > max { + return max + } + return v +} + +func runLsTypeWord(dirent os.FileInfo) string { + // find first character, the type char + // b Block special file. + // c Character special file. + // d Directory. + // l Symbolic link. + // s Socket link. + // p FIFO. + // - Regular file. + tc := '-' + mode := dirent.Mode() + if (mode & os.ModeDir) != 0 { + tc = 'd' + } else if (mode & os.ModeDevice) != 0 { + tc = 'b' + if (mode & os.ModeCharDevice) != 0 { + tc = 'c' + } + } else if (mode & os.ModeSymlink) != 0 { + tc = 'l' + } else if (mode & os.ModeSocket) != 0 { + tc = 's' + } else if (mode & os.ModeNamedPipe) != 0 { + tc = 'p' + } + + // owner + orc := '-' + if (mode & 0400) != 0 { + orc = 'r' + } + owc := '-' + if (mode & 0200) != 0 { + owc = 'w' + } + oxc := '-' + ox := (mode & 0100) != 0 + setuid := (mode & os.ModeSetuid) != 0 + if ox && setuid { + oxc = 's' + } else if setuid { + oxc = 'S' + } else if ox { + oxc = 'x' + } + + // group + grc := '-' + if (mode & 040) != 0 { + grc = 'r' + } + gwc := '-' + if (mode & 020) != 0 { + gwc = 'w' + } + gxc := '-' + gx := (mode & 010) != 0 + setgid := (mode & os.ModeSetgid) != 0 + if gx && setgid { + gxc = 's' + } else if setgid { + gxc = 'S' + } else if gx { + gxc = 'x' + } + + // all / others + arc := '-' + if (mode & 04) != 0 { + arc = 'r' + } + awc := '-' + if (mode & 02) != 0 { + awc = 'w' + } + axc := '-' + ax := (mode & 01) != 0 + sticky := (mode & os.ModeSticky) != 0 + if ax && sticky { + axc = 't' + } else if sticky { + axc = 'T' + } else if ax { + axc = 'x' + } + + return fmt.Sprintf("%c%c%c%c%c%c%c%c%c%c", tc, orc, owc, oxc, grc, gwc, gxc, arc, awc, axc) +} |