added statvfs@openssh.com extension request

client.go

@@ -7,6 +7,9 @@ import (
 	"path"
 	"sync"
 	"time"
+	"encoding/binary"
+	"bytes"
+	"errors"
 
 	"github.com/kr/fs"
 
@@ -420,6 +423,43 @@ func (c *Client) fstat(handle string) (*FileStat, error) {
 	}
 }
 
+// Get vfs stats from remote host.
+// Implementing statvfs@openssh.com SSH_FXP_EXTENDED feature
+// from http://www.opensource.apple.com/source/OpenSSH/OpenSSH-175/openssh/PROTOCOL?txt
+func (c *Client) StatVFS(path string) (*StatVFS, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	// send the StatVFS packet to the server
+	id := c.nextId()
+	typ, data, err := c.sendRequest(sshFxpStatvfsPacket{
+		Id:   id,
+		Path: path,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	switch typ {
+		// server responded with valid data
+		case ssh_FXP_EXTENDED_REPLY:
+			var response StatVFS
+			err = binary.Read(bytes.NewReader(data), binary.BigEndian, &response)
+			if err != nil {
+	    		return nil, errors.New("can not parse reply")
+			}
+
+			return &response, nil
+
+		// the resquest failed
+		case ssh_FXP_STATUS:
+			return nil, errors.New("statvfs@openssh.com failure")
+
+		default:
+			return nil, unimplementedPacketErr(typ)
+	}
+}
+
 // Join joins any number of path elements into a single path, adding a
 // separating slash if necessary. The result is Cleaned; in particular, all
 // empty strings are ignored.

packet.go

@@ -329,3 +329,45 @@ func (p sshFxpSetstatPacket) MarshalBinary() ([]byte, error) {
 	b = marshal(b, p.Attrs)
 	return b, nil
 }
+
+type sshFxpStatvfsPacket struct {
+	Id uint32
+	Path string
+}
+
+func (p sshFxpStatvfsPacket) MarshalBinary() ([]byte, error) {
+	l := 1 + 4 + // type(byte) + uint32
+		len(p.Path) + 
+		len("statvfs@openssh.com")
+
+
+	b := make([]byte, 0, l)
+	b = append(b, ssh_FXP_EXTENDED)
+	b = marshalUint32(b, p.Id)
+	b = marshalString(b, "statvfs@openssh.com")
+	b = marshalString(b, p.Path)
+	return b, nil
+}
+
+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 */
+}
+
+func (p *StatVFS) TotalSpace() uint64 {
+	return p.Frsize * p.Blocks
+}
+
+func (p *StatVFS) FreeSpace() uint64 {
+	return p.Frsize * p.Bfree
+}