diff options
Diffstat (limited to 'vendor/github.com/pkg/sftp/packet.go')
-rw-r--r-- | vendor/github.com/pkg/sftp/packet.go | 1276 |
1 files changed, 1276 insertions, 0 deletions
diff --git a/vendor/github.com/pkg/sftp/packet.go b/vendor/github.com/pkg/sftp/packet.go new file mode 100644 index 000000000..4059cf8e0 --- /dev/null +++ b/vendor/github.com/pkg/sftp/packet.go @@ -0,0 +1,1276 @@ +package sftp + +import ( + "bytes" + "encoding" + "encoding/binary" + "errors" + "fmt" + "io" + "os" + "reflect" +) + +var ( + errLongPacket = errors.New("packet too long") + errShortPacket = errors.New("packet too short") + errUnknownExtendedPacket = errors.New("unknown extended packet") +) + +const ( + maxMsgLength = 256 * 1024 + debugDumpTxPacket = false + debugDumpRxPacket = false + debugDumpTxPacketBytes = false + debugDumpRxPacketBytes = false +) + +func marshalUint32(b []byte, v uint32) []byte { + return append(b, byte(v>>24), byte(v>>16), byte(v>>8), byte(v)) +} + +func marshalUint64(b []byte, v uint64) []byte { + return marshalUint32(marshalUint32(b, uint32(v>>32)), uint32(v)) +} + +func marshalString(b []byte, v string) []byte { + return append(marshalUint32(b, uint32(len(v))), v...) +} + +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&sshFileXferAttrSize != 0 { + b = marshalUint64(b, fileStat.Size) + } + if flags&sshFileXferAttrUIDGID != 0 { + b = marshalUint32(b, fileStat.UID) + b = marshalUint32(b, fileStat.GID) + } + if flags&sshFileXferAttrPermissions != 0 { + b = marshalUint32(b, fileStat.Mode) + } + if flags&sshFileXferAttrACmodTime != 0 { + b = marshalUint32(b, fileStat.Atime) + b = marshalUint32(b, fileStat.Mtime) + } + + return b +} + +func marshalStatus(b []byte, err StatusError) []byte { + b = marshalUint32(b, err.Code) + b = marshalString(b, err.msg) + b = marshalString(b, err.lang) + return b +} + +func marshal(b []byte, v interface{}) []byte { + if v == nil { + return b + } + switch v := v.(type) { + case uint8: + return append(b, v) + case uint32: + return marshalUint32(b, v) + case uint64: + return marshalUint64(b, v) + case string: + return marshalString(b, v) + case os.FileInfo: + return marshalFileInfo(b, v) + default: + switch d := reflect.ValueOf(v); d.Kind() { + case reflect.Struct: + for i, n := 0, d.NumField(); i < n; i++ { + b = marshal(b, d.Field(i).Interface()) + } + return b + case reflect.Slice: + for i, n := 0, d.Len(); i < n; i++ { + b = marshal(b, d.Index(i).Interface()) + } + return b + default: + panic(fmt.Sprintf("marshal(%#v): cannot handle type %T", v, v)) + } + } +} + +func unmarshalUint32(b []byte) (uint32, []byte) { + v := uint32(b[3]) | uint32(b[2])<<8 | uint32(b[1])<<16 | uint32(b[0])<<24 + return v, b[4:] +} + +func unmarshalUint32Safe(b []byte) (uint32, []byte, error) { + var v uint32 + if len(b) < 4 { + return 0, nil, errShortPacket + } + v, b = unmarshalUint32(b) + return v, b, nil +} + +func unmarshalUint64(b []byte) (uint64, []byte) { + h, b := unmarshalUint32(b) + l, b := unmarshalUint32(b) + return uint64(h)<<32 | uint64(l), b +} + +func unmarshalUint64Safe(b []byte) (uint64, []byte, error) { + var v uint64 + if len(b) < 8 { + return 0, nil, errShortPacket + } + v, b = unmarshalUint64(b) + return v, b, nil +} + +func unmarshalString(b []byte) (string, []byte) { + n, b := unmarshalUint32(b) + return string(b[:n]), b[n:] +} + +func unmarshalStringSafe(b []byte) (string, []byte, error) { + n, b, err := unmarshalUint32Safe(b) + if err != nil { + return "", nil, err + } + if int64(n) > int64(len(b)) { + return "", nil, errShortPacket + } + return string(b[:n]), b[n:], nil +} + +func unmarshalAttrs(b []byte) (*FileStat, []byte) { + flags, b := unmarshalUint32(b) + return unmarshalFileStat(flags, b) +} + +func unmarshalFileStat(flags uint32, b []byte) (*FileStat, []byte) { + var fs FileStat + if flags&sshFileXferAttrSize == sshFileXferAttrSize { + fs.Size, b, _ = unmarshalUint64Safe(b) + } + if flags&sshFileXferAttrUIDGID == sshFileXferAttrUIDGID { + fs.UID, b, _ = unmarshalUint32Safe(b) + } + if flags&sshFileXferAttrUIDGID == sshFileXferAttrUIDGID { + fs.GID, b, _ = unmarshalUint32Safe(b) + } + if flags&sshFileXferAttrPermissions == sshFileXferAttrPermissions { + fs.Mode, b, _ = unmarshalUint32Safe(b) + } + if flags&sshFileXferAttrACmodTime == sshFileXferAttrACmodTime { + fs.Atime, b, _ = unmarshalUint32Safe(b) + fs.Mtime, b, _ = unmarshalUint32Safe(b) + } + if flags&sshFileXferAttrExtended == sshFileXferAttrExtended { + var count uint32 + count, b, _ = unmarshalUint32Safe(b) + ext := make([]StatExtended, count) + for i := uint32(0); i < count; i++ { + var typ string + var data string + typ, b, _ = unmarshalStringSafe(b) + data, b, _ = unmarshalStringSafe(b) + ext[i] = StatExtended{ + ExtType: typ, + ExtData: data, + } + } + fs.Extended = ext + } + return &fs, b +} + +func unmarshalStatus(id uint32, data []byte) error { + sid, data := unmarshalUint32(data) + if sid != id { + return &unexpectedIDErr{id, sid} + } + code, data := unmarshalUint32(data) + msg, data, _ := unmarshalStringSafe(data) + lang, _, _ := unmarshalStringSafe(data) + return &StatusError{ + Code: code, + msg: msg, + lang: lang, + } +} + +type packetMarshaler interface { + marshalPacket() (header, payload []byte, err error) +} + +func marshalPacket(m encoding.BinaryMarshaler) (header, payload []byte, err error) { + if m, ok := m.(packetMarshaler); ok { + return m.marshalPacket() + } + + header, err = m.MarshalBinary() + return +} + +// sendPacket marshals p according to RFC 4234. +func sendPacket(w io.Writer, m encoding.BinaryMarshaler) error { + header, payload, err := marshalPacket(m) + if err != nil { + return fmt.Errorf("binary marshaller failed: %w", err) + } + + length := len(header) + len(payload) - 4 // subtract the uint32(length) from the start + if debugDumpTxPacketBytes { + debug("send packet: %s %d bytes %x%x", fxp(header[4]), length, header[5:], payload) + } else if debugDumpTxPacket { + debug("send packet: %s %d bytes", fxp(header[4]), length) + } + + binary.BigEndian.PutUint32(header[:4], uint32(length)) + + if _, err := w.Write(header); err != nil { + return fmt.Errorf("failed to send packet: %w", err) + } + + if len(payload) > 0 { + if _, err := w.Write(payload); err != nil { + return fmt.Errorf("failed to send packet payload: %w", err) + } + } + + return nil +} + +func recvPacket(r io.Reader, alloc *allocator, orderID uint32) (uint8, []byte, error) { + var b []byte + if alloc != nil { + b = alloc.GetPage(orderID) + } else { + b = make([]byte, 4) + } + if _, err := io.ReadFull(r, b[:4]); err != nil { + return 0, nil, err + } + length, _ := unmarshalUint32(b) + if length > maxMsgLength { + debug("recv packet %d bytes too long", length) + return 0, nil, errLongPacket + } + if length == 0 { + debug("recv packet of 0 bytes too short") + return 0, nil, errShortPacket + } + if alloc == nil { + b = make([]byte, length) + } + if _, err := io.ReadFull(r, b[:length]); err != nil { + debug("recv packet %d bytes: err %v", length, err) + return 0, nil, err + } + if debugDumpRxPacketBytes { + debug("recv packet: %s %d bytes %x", fxp(b[0]), length, b[1:length]) + } else if debugDumpRxPacket { + debug("recv packet: %s %d bytes", fxp(b[0]), length) + } + return b[0], b[1:length], nil +} + +type extensionPair struct { + Name string + Data string +} + +func unmarshalExtensionPair(b []byte) (extensionPair, []byte, error) { + var ep extensionPair + var err error + ep.Name, b, err = unmarshalStringSafe(b) + if err != nil { + return ep, b, err + } + ep.Data, b, err = unmarshalStringSafe(b) + return ep, b, err +} + +// Here starts the definition of packets along with their MarshalBinary +// implementations. +// Manually writing the marshalling logic wins us a lot of time and +// allocation. + +type sshFxInitPacket struct { + Version uint32 + Extensions []extensionPair +} + +func (p *sshFxInitPacket) MarshalBinary() ([]byte, error) { + l := 4 + 1 + 4 // uint32(length) + byte(type) + uint32(version) + for _, e := range p.Extensions { + l += 4 + len(e.Name) + 4 + len(e.Data) + } + + b := make([]byte, 4, l) + b = append(b, sshFxpInit) + b = marshalUint32(b, p.Version) + + for _, e := range p.Extensions { + b = marshalString(b, e.Name) + b = marshalString(b, e.Data) + } + + return b, nil +} + +func (p *sshFxInitPacket) UnmarshalBinary(b []byte) error { + var err error + if p.Version, b, err = unmarshalUint32Safe(b); err != nil { + return err + } + for len(b) > 0 { + var ep extensionPair + ep, b, err = unmarshalExtensionPair(b) + if err != nil { + return err + } + p.Extensions = append(p.Extensions, ep) + } + return nil +} + +type sshFxVersionPacket struct { + Version uint32 + Extensions []sshExtensionPair +} + +type sshExtensionPair struct { + Name, Data string +} + +func (p *sshFxVersionPacket) MarshalBinary() ([]byte, error) { + l := 4 + 1 + 4 // uint32(length) + byte(type) + uint32(version) + for _, e := range p.Extensions { + l += 4 + len(e.Name) + 4 + len(e.Data) + } + + b := make([]byte, 4, l) + b = append(b, sshFxpVersion) + b = marshalUint32(b, p.Version) + + for _, e := range p.Extensions { + b = marshalString(b, e.Name) + b = marshalString(b, e.Data) + } + + return b, nil +} + +func marshalIDStringPacket(packetType byte, id uint32, str string) ([]byte, error) { + l := 4 + 1 + 4 + // uint32(length) + byte(type) + uint32(id) + 4 + len(str) + + b := make([]byte, 4, l) + b = append(b, packetType) + b = marshalUint32(b, id) + b = marshalString(b, str) + + return b, nil +} + +func unmarshalIDString(b []byte, id *uint32, str *string) error { + var err error + *id, b, err = unmarshalUint32Safe(b) + if err != nil { + return err + } + *str, _, err = unmarshalStringSafe(b) + return err +} + +type sshFxpReaddirPacket struct { + ID uint32 + Handle string +} + +func (p *sshFxpReaddirPacket) id() uint32 { return p.ID } + +func (p *sshFxpReaddirPacket) MarshalBinary() ([]byte, error) { + return marshalIDStringPacket(sshFxpReaddir, p.ID, p.Handle) +} + +func (p *sshFxpReaddirPacket) UnmarshalBinary(b []byte) error { + return unmarshalIDString(b, &p.ID, &p.Handle) +} + +type sshFxpOpendirPacket struct { + ID uint32 + Path string +} + +func (p *sshFxpOpendirPacket) id() uint32 { return p.ID } + +func (p *sshFxpOpendirPacket) MarshalBinary() ([]byte, error) { + return marshalIDStringPacket(sshFxpOpendir, p.ID, p.Path) +} + +func (p *sshFxpOpendirPacket) UnmarshalBinary(b []byte) error { + return unmarshalIDString(b, &p.ID, &p.Path) +} + +type sshFxpLstatPacket struct { + ID uint32 + Path string +} + +func (p *sshFxpLstatPacket) id() uint32 { return p.ID } + +func (p *sshFxpLstatPacket) MarshalBinary() ([]byte, error) { + return marshalIDStringPacket(sshFxpLstat, p.ID, p.Path) +} + +func (p *sshFxpLstatPacket) UnmarshalBinary(b []byte) error { + return unmarshalIDString(b, &p.ID, &p.Path) +} + +type sshFxpStatPacket struct { + ID uint32 + Path string +} + +func (p *sshFxpStatPacket) id() uint32 { return p.ID } + +func (p *sshFxpStatPacket) MarshalBinary() ([]byte, error) { + return marshalIDStringPacket(sshFxpStat, p.ID, p.Path) +} + +func (p *sshFxpStatPacket) UnmarshalBinary(b []byte) error { + return unmarshalIDString(b, &p.ID, &p.Path) +} + +type sshFxpFstatPacket struct { + ID uint32 + Handle string +} + +func (p *sshFxpFstatPacket) id() uint32 { return p.ID } + +func (p *sshFxpFstatPacket) MarshalBinary() ([]byte, error) { + return marshalIDStringPacket(sshFxpFstat, p.ID, p.Handle) +} + +func (p *sshFxpFstatPacket) UnmarshalBinary(b []byte) error { + return unmarshalIDString(b, &p.ID, &p.Handle) +} + +type sshFxpClosePacket struct { + ID uint32 + Handle string +} + +func (p *sshFxpClosePacket) id() uint32 { return p.ID } + +func (p *sshFxpClosePacket) MarshalBinary() ([]byte, error) { + return marshalIDStringPacket(sshFxpClose, p.ID, p.Handle) +} + +func (p *sshFxpClosePacket) UnmarshalBinary(b []byte) error { + return unmarshalIDString(b, &p.ID, &p.Handle) +} + +type sshFxpRemovePacket struct { + ID uint32 + Filename string +} + +func (p *sshFxpRemovePacket) id() uint32 { return p.ID } + +func (p *sshFxpRemovePacket) MarshalBinary() ([]byte, error) { + return marshalIDStringPacket(sshFxpRemove, p.ID, p.Filename) +} + +func (p *sshFxpRemovePacket) UnmarshalBinary(b []byte) error { + return unmarshalIDString(b, &p.ID, &p.Filename) +} + +type sshFxpRmdirPacket struct { + ID uint32 + Path string +} + +func (p *sshFxpRmdirPacket) id() uint32 { return p.ID } + +func (p *sshFxpRmdirPacket) MarshalBinary() ([]byte, error) { + return marshalIDStringPacket(sshFxpRmdir, p.ID, p.Path) +} + +func (p *sshFxpRmdirPacket) UnmarshalBinary(b []byte) error { + return unmarshalIDString(b, &p.ID, &p.Path) +} + +type sshFxpSymlinkPacket struct { + ID uint32 + Targetpath string + Linkpath string +} + +func (p *sshFxpSymlinkPacket) id() uint32 { return p.ID } + +func (p *sshFxpSymlinkPacket) MarshalBinary() ([]byte, error) { + l := 4 + 1 + 4 + // uint32(length) + byte(type) + uint32(id) + 4 + len(p.Targetpath) + + 4 + len(p.Linkpath) + + b := make([]byte, 4, l) + b = append(b, sshFxpSymlink) + b = marshalUint32(b, p.ID) + b = marshalString(b, p.Targetpath) + b = marshalString(b, p.Linkpath) + + return b, nil +} + +func (p *sshFxpSymlinkPacket) UnmarshalBinary(b []byte) error { + var err error + if p.ID, b, err = unmarshalUint32Safe(b); err != nil { + return err + } else if p.Targetpath, b, err = unmarshalStringSafe(b); err != nil { + return err + } else if p.Linkpath, _, err = unmarshalStringSafe(b); err != nil { + return err + } + return nil +} + +type sshFxpHardlinkPacket struct { + ID uint32 + Oldpath string + Newpath string +} + +func (p *sshFxpHardlinkPacket) id() uint32 { return p.ID } + +func (p *sshFxpHardlinkPacket) MarshalBinary() ([]byte, error) { + const ext = "hardlink@openssh.com" + l := 4 + 1 + 4 + // uint32(length) + byte(type) + uint32(id) + 4 + len(ext) + + 4 + len(p.Oldpath) + + 4 + len(p.Newpath) + + b := make([]byte, 4, l) + b = append(b, sshFxpExtended) + b = marshalUint32(b, p.ID) + b = marshalString(b, ext) + b = marshalString(b, p.Oldpath) + b = marshalString(b, p.Newpath) + + return b, nil +} + +type sshFxpReadlinkPacket struct { + ID uint32 + Path string +} + +func (p *sshFxpReadlinkPacket) id() uint32 { return p.ID } + +func (p *sshFxpReadlinkPacket) MarshalBinary() ([]byte, error) { + return marshalIDStringPacket(sshFxpReadlink, p.ID, p.Path) +} + +func (p *sshFxpReadlinkPacket) UnmarshalBinary(b []byte) error { + return unmarshalIDString(b, &p.ID, &p.Path) +} + +type sshFxpRealpathPacket struct { + ID uint32 + Path string +} + +func (p *sshFxpRealpathPacket) id() uint32 { return p.ID } + +func (p *sshFxpRealpathPacket) MarshalBinary() ([]byte, error) { + return marshalIDStringPacket(sshFxpRealpath, p.ID, p.Path) +} + +func (p *sshFxpRealpathPacket) UnmarshalBinary(b []byte) error { + return unmarshalIDString(b, &p.ID, &p.Path) +} + +type sshFxpNameAttr struct { + Name string + LongName string + Attrs []interface{} +} + +func (p *sshFxpNameAttr) MarshalBinary() ([]byte, error) { + var b []byte + b = marshalString(b, p.Name) + b = marshalString(b, p.LongName) + for _, attr := range p.Attrs { + b = marshal(b, attr) + } + return b, nil +} + +type sshFxpNamePacket struct { + ID uint32 + NameAttrs []*sshFxpNameAttr +} + +func (p *sshFxpNamePacket) marshalPacket() ([]byte, []byte, error) { + l := 4 + 1 + 4 + // uint32(length) + byte(type) + uint32(id) + 4 + + b := make([]byte, 4, l) + b = append(b, sshFxpName) + b = marshalUint32(b, p.ID) + b = marshalUint32(b, uint32(len(p.NameAttrs))) + + var payload []byte + for _, na := range p.NameAttrs { + ab, err := na.MarshalBinary() + if err != nil { + return nil, nil, err + } + + payload = append(payload, ab...) + } + + return b, payload, nil +} + +func (p *sshFxpNamePacket) MarshalBinary() ([]byte, error) { + header, payload, err := p.marshalPacket() + return append(header, payload...), err +} + +type sshFxpOpenPacket struct { + ID uint32 + Path string + Pflags uint32 + Flags uint32 // ignored +} + +func (p *sshFxpOpenPacket) id() uint32 { return p.ID } + +func (p *sshFxpOpenPacket) MarshalBinary() ([]byte, error) { + l := 4 + 1 + 4 + // uint32(length) + byte(type) + uint32(id) + 4 + len(p.Path) + + 4 + 4 + + b := make([]byte, 4, l) + b = append(b, sshFxpOpen) + b = marshalUint32(b, p.ID) + b = marshalString(b, p.Path) + b = marshalUint32(b, p.Pflags) + b = marshalUint32(b, p.Flags) + + return b, nil +} + +func (p *sshFxpOpenPacket) UnmarshalBinary(b []byte) error { + var err error + if p.ID, b, err = unmarshalUint32Safe(b); err != nil { + return err + } else if p.Path, b, err = unmarshalStringSafe(b); err != nil { + return err + } else if p.Pflags, b, err = unmarshalUint32Safe(b); err != nil { + return err + } else if p.Flags, _, err = unmarshalUint32Safe(b); err != nil { + return err + } + return nil +} + +type sshFxpReadPacket struct { + ID uint32 + Len uint32 + Offset uint64 + Handle string +} + +func (p *sshFxpReadPacket) id() uint32 { return p.ID } + +func (p *sshFxpReadPacket) MarshalBinary() ([]byte, error) { + l := 4 + 1 + 4 + // uint32(length) + byte(type) + uint32(id) + 4 + len(p.Handle) + + 8 + 4 // uint64 + uint32 + + b := make([]byte, 4, l) + b = append(b, sshFxpRead) + b = marshalUint32(b, p.ID) + b = marshalString(b, p.Handle) + b = marshalUint64(b, p.Offset) + b = marshalUint32(b, p.Len) + + return b, nil +} + +func (p *sshFxpReadPacket) UnmarshalBinary(b []byte) error { + var err error + if p.ID, b, err = unmarshalUint32Safe(b); err != nil { + return err + } else if p.Handle, b, err = unmarshalStringSafe(b); err != nil { + return err + } else if p.Offset, b, err = unmarshalUint64Safe(b); err != nil { + return err + } else if p.Len, _, err = unmarshalUint32Safe(b); err != nil { + return err + } + return nil +} + +// We need allocate bigger slices with extra capacity to avoid a re-allocation in sshFxpDataPacket.MarshalBinary +// So, we need: uint32(length) + byte(type) + uint32(id) + uint32(data_length) +const dataHeaderLen = 4 + 1 + 4 + 4 + +func (p *sshFxpReadPacket) getDataSlice(alloc *allocator, orderID uint32) []byte { + dataLen := p.Len + if dataLen > maxTxPacket { + dataLen = maxTxPacket + } + + if alloc != nil { + // GetPage returns a slice with capacity = maxMsgLength this is enough to avoid new allocations in + // sshFxpDataPacket.MarshalBinary + return alloc.GetPage(orderID)[:dataLen] + } + + // allocate with extra space for the header + return make([]byte, dataLen, dataLen+dataHeaderLen) +} + +type sshFxpRenamePacket struct { + ID uint32 + Oldpath string + Newpath string +} + +func (p *sshFxpRenamePacket) id() uint32 { return p.ID } + +func (p *sshFxpRenamePacket) MarshalBinary() ([]byte, error) { + l := 4 + 1 + 4 + // uint32(length) + byte(type) + uint32(id) + 4 + len(p.Oldpath) + + 4 + len(p.Newpath) + + b := make([]byte, 4, l) + b = append(b, sshFxpRename) + b = marshalUint32(b, p.ID) + b = marshalString(b, p.Oldpath) + b = marshalString(b, p.Newpath) + + return b, nil +} + +func (p *sshFxpRenamePacket) UnmarshalBinary(b []byte) error { + var err error + if p.ID, b, err = unmarshalUint32Safe(b); err != nil { + return err + } else if p.Oldpath, b, err = unmarshalStringSafe(b); err != nil { + return err + } else if p.Newpath, _, err = unmarshalStringSafe(b); err != nil { + return err + } + return nil +} + +type sshFxpPosixRenamePacket struct { + ID uint32 + Oldpath string + Newpath string +} + +func (p *sshFxpPosixRenamePacket) id() uint32 { return p.ID } + +func (p *sshFxpPosixRenamePacket) MarshalBinary() ([]byte, error) { + const ext = "posix-rename@openssh.com" + l := 4 + 1 + 4 + // uint32(length) + byte(type) + uint32(id) + 4 + len(ext) + + 4 + len(p.Oldpath) + + 4 + len(p.Newpath) + + b := make([]byte, 4, l) + b = append(b, sshFxpExtended) + b = marshalUint32(b, p.ID) + b = marshalString(b, ext) + b = marshalString(b, p.Oldpath) + b = marshalString(b, p.Newpath) + + return b, nil +} + +type sshFxpWritePacket struct { + ID uint32 + Length uint32 + Offset uint64 + Handle string + Data []byte +} + +func (p *sshFxpWritePacket) id() uint32 { return p.ID } + +func (p *sshFxpWritePacket) marshalPacket() ([]byte, []byte, error) { + l := 4 + 1 + 4 + // uint32(length) + byte(type) + uint32(id) + 4 + len(p.Handle) + + 8 + // uint64 + 4 + + b := make([]byte, 4, l) + b = append(b, sshFxpWrite) + b = marshalUint32(b, p.ID) + b = marshalString(b, p.Handle) + b = marshalUint64(b, p.Offset) + b = marshalUint32(b, p.Length) + + return b, p.Data, nil +} + +func (p *sshFxpWritePacket) MarshalBinary() ([]byte, error) { + header, payload, err := p.marshalPacket() + return append(header, payload...), err +} + +func (p *sshFxpWritePacket) UnmarshalBinary(b []byte) error { + var err error + if p.ID, b, err = unmarshalUint32Safe(b); err != nil { + return err + } else if p.Handle, b, err = unmarshalStringSafe(b); err != nil { + return err + } else if p.Offset, b, err = unmarshalUint64Safe(b); err != nil { + return err + } else if p.Length, b, err = unmarshalUint32Safe(b); err != nil { + return err + } else if uint32(len(b)) < p.Length { + return errShortPacket + } + + p.Data = b[:p.Length] + return nil +} + +type sshFxpMkdirPacket struct { + ID uint32 + Flags uint32 // ignored + Path string +} + +func (p *sshFxpMkdirPacket) id() uint32 { return p.ID } + +func (p *sshFxpMkdirPacket) MarshalBinary() ([]byte, error) { + l := 4 + 1 + 4 + // uint32(length) + byte(type) + uint32(id) + 4 + len(p.Path) + + 4 // uint32 + + b := make([]byte, 4, l) + b = append(b, sshFxpMkdir) + b = marshalUint32(b, p.ID) + b = marshalString(b, p.Path) + b = marshalUint32(b, p.Flags) + + return b, nil +} + +func (p *sshFxpMkdirPacket) UnmarshalBinary(b []byte) error { + var err error + if p.ID, b, err = unmarshalUint32Safe(b); err != nil { + return err + } else if p.Path, b, err = unmarshalStringSafe(b); err != nil { + return err + } else if p.Flags, _, err = unmarshalUint32Safe(b); err != nil { + return err + } + return nil +} + +type sshFxpSetstatPacket struct { + ID uint32 + Flags uint32 + Path string + Attrs interface{} +} + +type sshFxpFsetstatPacket struct { + ID uint32 + Flags uint32 + Handle string + Attrs interface{} +} + +func (p *sshFxpSetstatPacket) id() uint32 { return p.ID } +func (p *sshFxpFsetstatPacket) id() uint32 { return p.ID } + +func (p *sshFxpSetstatPacket) marshalPacket() ([]byte, []byte, error) { + l := 4 + 1 + 4 + // uint32(length) + byte(type) + uint32(id) + 4 + len(p.Path) + + 4 // uint32 + + b := make([]byte, 4, l) + b = append(b, sshFxpSetstat) + b = marshalUint32(b, p.ID) + b = marshalString(b, p.Path) + b = marshalUint32(b, p.Flags) + + payload := marshal(nil, p.Attrs) + + return b, payload, nil +} + +func (p *sshFxpSetstatPacket) MarshalBinary() ([]byte, error) { + header, payload, err := p.marshalPacket() + return append(header, payload...), err +} + +func (p *sshFxpFsetstatPacket) marshalPacket() ([]byte, []byte, error) { + l := 4 + 1 + 4 + // uint32(length) + byte(type) + uint32(id) + 4 + len(p.Handle) + + 4 // uint32 + + b := make([]byte, 4, l) + b = append(b, sshFxpFsetstat) + b = marshalUint32(b, p.ID) + b = marshalString(b, p.Handle) + b = marshalUint32(b, p.Flags) + + payload := marshal(nil, p.Attrs) + + return b, payload, nil +} + +func (p *sshFxpFsetstatPacket) MarshalBinary() ([]byte, error) { + header, payload, err := p.marshalPacket() + return append(header, payload...), err +} + +func (p *sshFxpSetstatPacket) UnmarshalBinary(b []byte) error { + var err error + if p.ID, b, err = unmarshalUint32Safe(b); err != nil { + return err + } else if p.Path, b, err = unmarshalStringSafe(b); err != nil { + return err + } else if p.Flags, b, err = unmarshalUint32Safe(b); err != nil { + return err + } + p.Attrs = b + return nil +} + +func (p *sshFxpFsetstatPacket) UnmarshalBinary(b []byte) error { + var err error + if p.ID, b, err = unmarshalUint32Safe(b); err != nil { + return err + } else if p.Handle, b, err = unmarshalStringSafe(b); err != nil { + return err + } else if p.Flags, b, err = unmarshalUint32Safe(b); err != nil { + return err + } + p.Attrs = b + return nil +} + +type sshFxpHandlePacket struct { + ID uint32 + Handle string +} + +func (p *sshFxpHandlePacket) MarshalBinary() ([]byte, error) { + l := 4 + 1 + 4 + // uint32(length) + byte(type) + uint32(id) + 4 + len(p.Handle) + + b := make([]byte, 4, l) + b = append(b, sshFxpHandle) + b = marshalUint32(b, p.ID) + b = marshalString(b, p.Handle) + + return b, nil +} + +type sshFxpStatusPacket struct { + ID uint32 + StatusError +} + +func (p *sshFxpStatusPacket) MarshalBinary() ([]byte, error) { + l := 4 + 1 + 4 + // uint32(length) + byte(type) + uint32(id) + 4 + + 4 + len(p.StatusError.msg) + + 4 + len(p.StatusError.lang) + + b := make([]byte, 4, l) + b = append(b, sshFxpStatus) + b = marshalUint32(b, p.ID) + b = marshalStatus(b, p.StatusError) + + return b, nil +} + +type sshFxpDataPacket struct { + ID uint32 + Length uint32 + Data []byte +} + +func (p *sshFxpDataPacket) marshalPacket() ([]byte, []byte, error) { + l := 4 + 1 + 4 + // uint32(length) + byte(type) + uint32(id) + 4 + + b := make([]byte, 4, l) + b = append(b, sshFxpData) + b = marshalUint32(b, p.ID) + b = marshalUint32(b, p.Length) + + return b, p.Data, nil +} + +// MarshalBinary encodes the receiver into a binary form and returns the result. +// To avoid a new allocation the Data slice must have a capacity >= Length + 9 +// +// This is hand-coded rather than just append(header, payload...), +// in order to try and reuse the r.Data backing store in the packet. +func (p *sshFxpDataPacket) MarshalBinary() ([]byte, error) { + b := append(p.Data, make([]byte, dataHeaderLen)...) + copy(b[dataHeaderLen:], p.Data[:p.Length]) + // b[0:4] will be overwritten with the length in sendPacket + b[4] = sshFxpData + binary.BigEndian.PutUint32(b[5:9], p.ID) + binary.BigEndian.PutUint32(b[9:13], p.Length) + return b, nil +} + +func (p *sshFxpDataPacket) UnmarshalBinary(b []byte) error { + var err error + if p.ID, b, err = unmarshalUint32Safe(b); err != nil { + return err + } else if p.Length, b, err = unmarshalUint32Safe(b); err != nil { + return err + } else if uint32(len(b)) < p.Length { + return errShortPacket + } + + p.Data = b[:p.Length] + return nil +} + +type sshFxpStatvfsPacket struct { + ID uint32 + Path string +} + +func (p *sshFxpStatvfsPacket) id() uint32 { return p.ID } + +func (p *sshFxpStatvfsPacket) MarshalBinary() ([]byte, error) { + const ext = "statvfs@openssh.com" + l := 4 + 1 + 4 + // uint32(length) + byte(type) + uint32(id) + 4 + len(ext) + + 4 + len(p.Path) + + b := make([]byte, 4, l) + b = append(b, sshFxpExtended) + b = marshalUint32(b, p.ID) + b = marshalString(b, ext) + b = marshalString(b, p.Path) + + return b, nil +} + +// A StatVFS contains statistics about a filesystem. +type StatVFS struct { + ID uint32 + Bsize uint64 /* file system block size */ + Frsize uint64 /* fundamental fs block size */ + Blocks uint64 /* number of blocks (unit f_frsize) */ + Bfree uint64 /* free blocks in file system */ + Bavail uint64 /* free blocks for non-root */ + Files uint64 /* total file inodes */ + Ffree uint64 /* free file inodes */ + Favail uint64 /* free file inodes for to non-root */ + Fsid uint64 /* file system id */ + Flag uint64 /* bit mask of f_flag values */ + Namemax uint64 /* maximum filename length */ +} + +// TotalSpace calculates the amount of total space in a filesystem. +func (p *StatVFS) TotalSpace() uint64 { + return p.Frsize * p.Blocks +} + +// FreeSpace calculates the amount of free space in a filesystem. +func (p *StatVFS) FreeSpace() uint64 { + return p.Frsize * p.Bfree +} + +// marshalPacket converts to ssh_FXP_EXTENDED_REPLY packet binary format +func (p *StatVFS) marshalPacket() ([]byte, []byte, error) { + header := []byte{0, 0, 0, 0, sshFxpExtendedReply} + + var buf bytes.Buffer + err := binary.Write(&buf, binary.BigEndian, p) + + return header, buf.Bytes(), err +} + +// MarshalBinary encodes the StatVFS as an SSH_FXP_EXTENDED_REPLY packet. +func (p *StatVFS) MarshalBinary() ([]byte, error) { + header, payload, err := p.marshalPacket() + return append(header, payload...), err +} + +type sshFxpFsyncPacket struct { + ID uint32 + Handle string +} + +func (p *sshFxpFsyncPacket) id() uint32 { return p.ID } + +func (p *sshFxpFsyncPacket) MarshalBinary() ([]byte, error) { + const ext = "fsync@openssh.com" + l := 4 + 1 + 4 + // uint32(length) + byte(type) + uint32(id) + 4 + len(ext) + + 4 + len(p.Handle) + + b := make([]byte, 4, l) + b = append(b, sshFxpExtended) + b = marshalUint32(b, p.ID) + b = marshalString(b, ext) + b = marshalString(b, p.Handle) + + return b, nil +} + +type sshFxpExtendedPacket struct { + ID uint32 + ExtendedRequest string + SpecificPacket interface { + serverRespondablePacket + readonly() bool + } +} + +func (p *sshFxpExtendedPacket) id() uint32 { return p.ID } +func (p *sshFxpExtendedPacket) readonly() bool { + if p.SpecificPacket == nil { + return true + } + return p.SpecificPacket.readonly() +} + +func (p *sshFxpExtendedPacket) respond(svr *Server) responsePacket { + if p.SpecificPacket == nil { + return statusFromError(p.ID, nil) + } + return p.SpecificPacket.respond(svr) +} + +func (p *sshFxpExtendedPacket) UnmarshalBinary(b []byte) error { + var err error + bOrig := b + if p.ID, b, err = unmarshalUint32Safe(b); err != nil { + return err + } else if p.ExtendedRequest, _, err = unmarshalStringSafe(b); err != nil { + return err + } + + // specific unmarshalling + switch p.ExtendedRequest { + case "statvfs@openssh.com": + p.SpecificPacket = &sshFxpExtendedPacketStatVFS{} + case "posix-rename@openssh.com": + p.SpecificPacket = &sshFxpExtendedPacketPosixRename{} + case "hardlink@openssh.com": + p.SpecificPacket = &sshFxpExtendedPacketHardlink{} + default: + return fmt.Errorf("packet type %v: %w", p.SpecificPacket, errUnknownExtendedPacket) + } + + return p.SpecificPacket.UnmarshalBinary(bOrig) +} + +type sshFxpExtendedPacketStatVFS struct { + ID uint32 + ExtendedRequest string + Path string +} + +func (p *sshFxpExtendedPacketStatVFS) id() uint32 { return p.ID } +func (p *sshFxpExtendedPacketStatVFS) readonly() bool { return true } +func (p *sshFxpExtendedPacketStatVFS) UnmarshalBinary(b []byte) error { + var err error + if p.ID, b, err = unmarshalUint32Safe(b); err != nil { + return err + } else if p.ExtendedRequest, b, err = unmarshalStringSafe(b); err != nil { + return err + } else if p.Path, _, err = unmarshalStringSafe(b); err != nil { + return err + } + return nil +} + +type sshFxpExtendedPacketPosixRename struct { + ID uint32 + ExtendedRequest string + Oldpath string + Newpath string +} + +func (p *sshFxpExtendedPacketPosixRename) id() uint32 { return p.ID } +func (p *sshFxpExtendedPacketPosixRename) readonly() bool { return false } +func (p *sshFxpExtendedPacketPosixRename) UnmarshalBinary(b []byte) error { + var err error + if p.ID, b, err = unmarshalUint32Safe(b); err != nil { + return err + } else if p.ExtendedRequest, b, err = unmarshalStringSafe(b); err != nil { + return err + } else if p.Oldpath, b, err = unmarshalStringSafe(b); err != nil { + return err + } else if p.Newpath, _, err = unmarshalStringSafe(b); err != nil { + return err + } + return nil +} + +func (p *sshFxpExtendedPacketPosixRename) respond(s *Server) responsePacket { + err := os.Rename(toLocalPath(p.Oldpath), toLocalPath(p.Newpath)) + return statusFromError(p.ID, err) +} + +type sshFxpExtendedPacketHardlink struct { + ID uint32 + ExtendedRequest string + Oldpath string + Newpath string +} + +// https://github.com/openssh/openssh-portable/blob/master/PROTOCOL +func (p *sshFxpExtendedPacketHardlink) id() uint32 { return p.ID } +func (p *sshFxpExtendedPacketHardlink) readonly() bool { return true } +func (p *sshFxpExtendedPacketHardlink) UnmarshalBinary(b []byte) error { + var err error + if p.ID, b, err = unmarshalUint32Safe(b); err != nil { + return err + } else if p.ExtendedRequest, b, err = unmarshalStringSafe(b); err != nil { + return err + } else if p.Oldpath, b, err = unmarshalStringSafe(b); err != nil { + return err + } else if p.Newpath, _, err = unmarshalStringSafe(b); err != nil { + return err + } + return nil +} + +func (p *sshFxpExtendedPacketHardlink) respond(s *Server) responsePacket { + err := os.Link(toLocalPath(p.Oldpath), toLocalPath(p.Newpath)) + return statusFromError(p.ID, err) +} |