1 files changed, 48 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/internal/nettest/helper_bsd.go b/vendor/golang.org/x/net/internal/nettest/helper_bsd.go
new file mode 100644
index 000000000..b2308a0e8
--- /dev/null
+++ b/vendor/golang.org/x/net/internal/nettest/helper_bsd.go
@@ -0,0 +1,48 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin dragonfly freebsd netbsd openbsd
+
+package nettest
+
+import (
+	"runtime"
+	"strconv"
+	"strings"
+	"syscall"
+)
+
+func supportsIPv6MulticastDeliveryOnLoopback() bool {
+	switch runtime.GOOS {
+	case "freebsd":
+		// See http://www.freebsd.org/cgi/query-pr.cgi?pr=180065.
+		// Even after the fix, it looks like the latest
+		// kernels don't deliver link-local scoped multicast
+		// packets correctly.
+		return false
+	case "darwin":
+		// See http://support.apple.com/kb/HT1633.
+		s, err := syscall.Sysctl("kern.osrelease")
+		if err != nil {
+			return false
+		}
+		ss := strings.Split(s, ".")
+		if len(ss) == 0 {
+			return false
+		}
+		// OS X 10.9 (Darwin 13) or above seems to do the
+		// right thing; preserving the packet header as it's
+		// needed for the checksum calcuration with pseudo
+		// header on loopback multicast delivery process.
+		// If not, you'll probably see what is the slow-acting
+		// kernel crash caused by lazy mbuf corruption.
+		// See ip6_mloopback in netinet6/ip6_output.c.
+		if mjver, err := strconv.Atoi(ss[0]); err != nil || mjver < 13 {
+			return false
+		}
+		return true
+	default:
+		return true
+	}
+}