runtime-v2: add validation for runtime name

Ace-Tang · Ace-Tang · commit 7b1b16b74121 · 2018-10-19T15:19:45.000+08:00
add validation for runtime name, if runtime name is invalid,
containerd will got panic.

Signed-off-by: Ace-Tang &lt;aceapril@126.com&gt;
diff --git a/runtime/v2/shim/util.go b/runtime/v2/shim/util.go
@@ -49,6 +49,9 @@ func Command(ctx context.Context, runtime, containerdAddress, path string, cmdAr
 	}
 	args = append(args, cmdArgs...)
 	name := BinaryName(runtime)
+	if name == "" {
+		return nil, fmt.Errorf("invalid runtime name %s, correct runtime name should format like io.containerd.runc.v1", runtime)
+	}
 	var cmdPath string
 	var lerr error
 	if cmdPath, lerr = exec.LookPath(name); lerr != nil {
@@ -69,10 +72,15 @@ func Command(ctx context.Context, runtime, containerdAddress, path string, cmdAr
 	return cmd, nil
 }
 
-// BinaryName returns the shim binary name from the runtime name
+// BinaryName returns the shim binary name from the runtime name,
+// empty string returns means runtime name is invalid
 func BinaryName(runtime string) string {
+	// runtime name should format like $prefix.name.version
 	parts := strings.Split(runtime, ".")
-	// TODO: add validation for runtime
+	if len(parts) < 2 {
+		return ""
+	}
+
 	return fmt.Sprintf(shimBinaryFormat, parts[len(parts)-2], parts[len(parts)-1])
 }
 
