feat: Waku v2 bridge

Issue #12610

vendor/github.com/anacrolix/mmsg/socket/msghdr_linux.go

@@ -0,0 +1,36 @@
+// Copyright 2017 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.
+
+package socket
+
+import "unsafe"
+
+func (h *msghdr) pack(vs []iovec, bs [][]byte, oob []byte, sa []byte) {
+	for i := range vs {
+		vs[i].set(bs[i])
+	}
+	h.setIov(vs)
+	if len(oob) > 0 {
+		h.setControl(oob)
+	}
+	if sa != nil {
+		h.Name = (*byte)(unsafe.Pointer(&sa[0]))
+		h.Namelen = uint32(len(sa))
+	}
+}
+
+func (h *msghdr) name() []byte {
+	if h.Name != nil && h.Namelen > 0 {
+		return (*[sizeofSockaddrInet6]byte)(unsafe.Pointer(h.Name))[:h.Namelen]
+	}
+	return nil
+}
+
+func (h *msghdr) controllen() int {
+	return int(h.Controllen)
+}
+
+func (h *msghdr) flags() int {
+	return int(h.Flags)
+}