You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: mmsghdr_unix.go
    path of file: ./repos/sliver/vendor/golang.org/x/net/internal/socket
    
    the code of the file until where you have to start completion: // 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.

//go:build aix || linux || netbsd
// +build aix linux netbsd

packa
    
func (hs mmsghdrs) unpack(ms []Message, parseFn func([]byte, string) (net.Addr, error), hint string) error {
	for i := range hs {
		ms[i].N = int(hs[i].Len)
		ms[i].NN = hs[i].Hdr.controllen()
		ms[i].Flags = hs[i].Hdr.flags()
		if parseFn != nil {
			var err error
			ms[i].Addr, err = parseFn(hs[i].Hdr.name(), hint)
			if err != nil {
				return err
			}
		}
	}
	return nil
}