src/pkg/net/cgo_linux.go

// Copyright 2011 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 cgo,!netgo

package net

/*
#include <netdb.h>
*/
import "C"

func cgoAddrInfoFlags() C.int {
	// NOTE(rsc): In theory there are approximately balanced
	// arguments for and against including AI_ADDRCONFIG
	// in the flags (it includes IPv4 results only on IPv4 systems,
	// and similarly for IPv6), but in practice setting it causes
	// getaddrinfo to return the wrong canonical name on Linux.
	// So definitely leave it out.
	return C.AI_CANONNAME | C.AI_V4MAPPED | C.AI_ALL
}