Exemplo n.º 1
0
func (u *Ufs) Wstat(req *srv.Req) {
	var changed bool
	fid := req.Fid.Aux.(*Fid)
	err := fid.stat()
	if err != nil {
		req.RespondError(err)
		return
	}

	dir := &req.Tc.Dir
	if dir.Mode != 0xFFFFFFFF {
		changed = true
		mode := dir.Mode & 0777
		if req.Conn.Dotu {
			if dir.Mode&ninep.DMSETUID > 0 {
				mode |= syscall.S_ISUID
			}
			if dir.Mode&ninep.DMSETGID > 0 {
				mode |= syscall.S_ISGID
			}
		}
		e := os.Chmod(fid.path, os.FileMode(mode))
		if e != nil {
			req.RespondError(toError(e))
			return
		}
	}

	uid, gid := ninep.NOUID, ninep.NOUID
	if req.Conn.Dotu {
		uid = dir.Uidnum
		gid = dir.Gidnum
	}

	// Try to find local uid, gid by name.
	if (dir.Uid != "" || dir.Gid != "") && !req.Conn.Dotu {
		changed = true
		uid, err = lookup(dir.Uid, false)
		if err != nil {
			req.RespondError(err)
			return
		}

		// BUG(akumar): Lookup will never find gids
		// corresponding to group names, because
		// it only operates on user names.
		gid, err = lookup(dir.Gid, true)
		if err != nil {
			req.RespondError(err)
			return
		}
	}

	if uid != ninep.NOUID || gid != ninep.NOUID {
		changed = true
		e := os.Chown(fid.path, int(uid), int(gid))
		if e != nil {
			req.RespondError(toError(e))
			return
		}
	}

	if dir.Name != "" {
		changed = true
		// If we path.Join dir.Name to / before adding it to
		// the fid path, that ensures nobody gets to walk out of the
		// root of this server.
		newname := path.Join(path.Dir(fid.path), path.Join("/", dir.Name))

		// absolute renaming. Ufs can do this, so let's support it.
		// We'll allow an absolute path in the Name and, if it is,
		// we will make it relative to root. This is a gigantic performance
		// improvement in systems that allow it.
		if filepath.IsAbs(dir.Name) {
			newname = path.Join(u.Root, dir.Name)
		}

		err := syscall.Rename(fid.path, newname)
		if err != nil {
			req.RespondError(toError(err))
			return
		}
		fid.path = newname
	}

	if dir.Length != 0xFFFFFFFFFFFFFFFF {
		changed = true
		e := os.Truncate(fid.path, int64(dir.Length))
		if e != nil {
			req.RespondError(toError(e))
			return
		}
	}

	// If either mtime or atime need to be changed, then
	// we must change both.
	if dir.Mtime != ^uint32(0) || dir.Atime != ^uint32(0) {
		changed = true
		mt, at := time.Unix(int64(dir.Mtime), 0), time.Unix(int64(dir.Atime), 0)
		if cmt, cat := (dir.Mtime == ^uint32(0)), (dir.Atime == ^uint32(0)); cmt || cat {
			st, e := os.Stat(fid.path)
			if e != nil {
				req.RespondError(toError(e))
				return
			}
			switch cmt {
			case true:
				mt = st.ModTime()
			default:
				at = atime(st.Sys().(*syscall.Stat_t))
			}
		}
		e := os.Chtimes(fid.path, at, mt)
		if e != nil {
			req.RespondError(toError(e))
			return
		}
	}

	if !changed && fid.file != nil {
		fid.file.Sync()
	}
	req.RespondRwstat()
}