ptp: add ipv6 support

* Wait for addresses to leave tentative state before setting routes
* Enable forwarding correctly
* Set up masquerading according to the active protocol

pkg/testutils/ping.go

@@ -0,0 +1,55 @@
+// Copyright 2017 CNI authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package testutils
+
+import (
+	"bytes"
+	"fmt"
+	"os/exec"
+	"strconv"
+	"syscall"
+)
+
+// Ping shells out to the `ping` command. Returns nil if successful.
+func Ping(saddr, daddr string, isV6 bool, timeoutSec int) error {
+	args := []string{
+		"-c", "1",
+		"-W", strconv.Itoa(timeoutSec),
+		"-I", saddr,
+		daddr,
+	}
+
+	bin := "ping"
+	if isV6 {
+		bin = "ping6"
+	}
+
+	cmd := exec.Command(bin, args...)
+	var stderr bytes.Buffer
+	cmd.Stderr = &stderr
+
+	if err := cmd.Run(); err != nil {
+		switch e := err.(type) {
+		case *exec.ExitError:
+			return fmt.Errorf("%v exit status %d: %s",
+				args, e.Sys().(syscall.WaitStatus).ExitStatus(),
+				stderr.String())
+		default:
+			return err
+		}
+	}
+
+	return nil
+}