1 files changed, 238 insertions, 0 deletions
diff --git a/vendor/github.com/pkg/sftp/request-server.go b/vendor/github.com/pkg/sftp/request-server.go
new file mode 100644
index 00000000..ec64a1ff
--- /dev/null
+++ b/vendor/github.com/pkg/sftp/request-server.go
@@ -0,0 +1,238 @@
+package sftp
+
+import (
+	"context"
+	"encoding"
+	"io"
+	"path"
+	"path/filepath"
+	"strconv"
+	"sync"
+	"syscall"
+
+	"github.com/pkg/errors"
+)
+
+var maxTxPacket uint32 = 1 << 15
+
+// Handlers contains the 4 SFTP server request handlers.
+type Handlers struct {
+	FileGet  FileReader
+	FilePut  FileWriter
+	FileCmd  FileCmder
+	FileList FileLister
+}
+
+// RequestServer abstracts the sftp protocol with an http request-like protocol
+type RequestServer struct {
+	*serverConn
+	Handlers        Handlers
+	pktMgr          *packetManager
+	openRequests    map[string]*Request
+	openRequestLock sync.RWMutex
+	handleCount     int
+}
+
+// NewRequestServer creates/allocates/returns new RequestServer.
+// Normally there there will be one server per user-session.
+func NewRequestServer(rwc io.ReadWriteCloser, h Handlers) *RequestServer {
+	svrConn := &serverConn{
+		conn: conn{
+			Reader:      rwc,
+			WriteCloser: rwc,
+		},
+	}
+	return &RequestServer{
+		serverConn:   svrConn,
+		Handlers:     h,
+		pktMgr:       newPktMgr(svrConn),
+		openRequests: make(map[string]*Request),
+	}
+}
+
+// New Open packet/Request
+func (rs *RequestServer) nextRequest(r *Request) string {
+	rs.openRequestLock.Lock()
+	defer rs.openRequestLock.Unlock()
+	rs.handleCount++
+	handle := strconv.Itoa(rs.handleCount)
+	rs.openRequests[handle] = r
+	return handle
+}
+
+// Returns Request from openRequests, bool is false if it is missing
+// If the method is different, save/return a new Request w/ that Method.
+//
+// The Requests in openRequests work essentially as open file descriptors that
+// you can do different things with. What you are doing with it are denoted by
+// the first packet of that type (read/write/etc). We create a new Request when
+// it changes to set the request.Method attribute in a thread safe way.
+func (rs *RequestServer) getRequest(handle, method string) (*Request, bool) {
+	rs.openRequestLock.RLock()
+	r, ok := rs.openRequests[handle]
+	rs.openRequestLock.RUnlock()
+	if !ok || r.Method == method {
+		return r, ok
+	}
+	// if we make it here we need to replace the request
+	rs.openRequestLock.Lock()
+	defer rs.openRequestLock.Unlock()
+	r, ok = rs.openRequests[handle]
+	if !ok || r.Method == method { // re-check needed b/c lock race
+		return r, ok
+	}
+	r = r.copy()
+	r.Method = method
+	rs.openRequests[handle] = r
+	return r, ok
+}
+
+func (rs *RequestServer) closeRequest(handle string) error {
+	rs.openRequestLock.Lock()
+	defer rs.openRequestLock.Unlock()
+	if r, ok := rs.openRequests[handle]; ok {
+		delete(rs.openRequests, handle)
+		return r.close()
+	}
+	return syscall.EBADF
+}
+
+// Close the read/write/closer to trigger exiting the main server loop
+func (rs *RequestServer) Close() error { return rs.conn.Close() }
+
+// Serve requests for user session
+func (rs *RequestServer) Serve() error {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	var wg sync.WaitGroup
+	runWorker := func(ch requestChan) {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			if err := rs.packetWorker(ctx, ch); err != nil {
+				rs.conn.Close() // shuts down recvPacket
+			}
+		}()
+	}
+	pktChan := rs.pktMgr.workerChan(runWorker)
+
+	var err error
+	var pkt requestPacket
+	var pktType uint8
+	var pktBytes []byte
+	for {
+		pktType, pktBytes, err = rs.recvPacket()
+		if err != nil {
+			break
+		}
+
+		pkt, err = makePacket(rxPacket{fxp(pktType), pktBytes})
+		if err != nil {
+			debug("makePacket err: %v", err)
+			rs.conn.Close() // shuts down recvPacket
+			break
+		}
+
+		pktChan <- pkt
+	}
+
+	close(pktChan) // shuts down sftpServerWorkers
+	wg.Wait()      // wait for all workers to exit
+
+	// make sure all open requests are properly closed
+	// (eg. possible on dropped connections, client crashes, etc.)
+	for handle, req := range rs.openRequests {
+		delete(rs.openRequests, handle)
+		req.close()
+	}
+
+	return err
+}
+
+func (rs *RequestServer) packetWorker(
+	ctx context.Context, pktChan chan requestPacket,
+) error {
+	for pkt := range pktChan {
+		var rpkt responsePacket
+		switch pkt := pkt.(type) {
+		case *sshFxInitPacket:
+			rpkt = sshFxVersionPacket{sftpProtocolVersion, nil}
+		case *sshFxpClosePacket:
+			handle := pkt.getHandle()
+			rpkt = statusFromError(pkt, rs.closeRequest(handle))
+		case *sshFxpRealpathPacket:
+			rpkt = cleanPacketPath(pkt)
+		case *sshFxpOpendirPacket:
+			request := requestFromPacket(ctx, pkt)
+			handle := rs.nextRequest(request)
+			rpkt = sshFxpHandlePacket{pkt.id(), handle}
+		case *sshFxpOpenPacket:
+			request := requestFromPacket(ctx, pkt)
+			handle := rs.nextRequest(request)
+			rpkt = sshFxpHandlePacket{pkt.id(), handle}
+			if pkt.hasPflags(ssh_FXF_CREAT) {
+				if p := request.call(rs.Handlers, pkt); !isOk(p) {
+					rpkt = p // if error in write, return it
+				}
+			}
+		case hasHandle:
+			handle := pkt.getHandle()
+			request, ok := rs.getRequest(handle, requestMethod(pkt))
+			if !ok {
+				rpkt = statusFromError(pkt, syscall.EBADF)
+			} else {
+				rpkt = request.call(rs.Handlers, pkt)
+			}
+		case hasPath:
+			request := requestFromPacket(ctx, pkt)
+			rpkt = request.call(rs.Handlers, pkt)
+			request.close()
+		default:
+			return errors.Errorf("unexpected packet type %T", pkt)
+		}
+
+		err := rs.sendPacket(rpkt)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// True is responsePacket is an OK status packet
+func isOk(rpkt responsePacket) bool {
+	p, ok := rpkt.(sshFxpStatusPacket)
+	return ok && p.StatusError.Code == ssh_FX_OK
+}
+
+// clean and return name packet for file
+func cleanPacketPath(pkt *sshFxpRealpathPacket) responsePacket {
+	path := cleanPath(pkt.getPath())
+	return &sshFxpNamePacket{
+		ID: pkt.id(),
+		NameAttrs: []sshFxpNameAttr{{
+			Name:     path,
+			LongName: path,
+			Attrs:    emptyFileStat,
+		}},
+	}
+}
+
+// Makes sure we have a clean POSIX (/) absolute path to work with
+func cleanPath(p string) string {
+	p = filepath.ToSlash(p)
+	if !filepath.IsAbs(p) {
+		p = "/" + p
+	}
+	return path.Clean(p)
+}
+
+// Wrap underlying connection methods to use packetManager
+func (rs *RequestServer) sendPacket(m encoding.BinaryMarshaler) error {
+	if pkt, ok := m.(responsePacket); ok {
+		rs.pktMgr.readyPacket(pkt)
+	} else {
+		return errors.Errorf("unexpected packet type %T", m)
+	}
+	return nil
+}