Fix dependencies

vendor/golang.org/x/net/ipv4/helper.go

@@ -1,77 +0,0 @@
-// Copyright 2012 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 ipv4
-
-import (
-	"errors"
-	"net"
-	"runtime"
-
-	"golang.org/x/net/internal/socket"
-)
-
-var (
-	errInvalidConn       = errors.New("invalid connection")
-	errMissingAddress    = errors.New("missing address")
-	errNilHeader         = errors.New("nil header")
-	errHeaderTooShort    = errors.New("header too short")
-	errExtHeaderTooShort = errors.New("extension header too short")
-	errInvalidConnType   = errors.New("invalid conn type")
-	errNotImplemented    = errors.New("not implemented on " + runtime.GOOS + "/" + runtime.GOARCH)
-
-	// See https://www.freebsd.org/doc/en/books/porters-handbook/versions.html.
-	freebsdVersion  uint32
-	compatFreeBSD32 bool // 386 emulation on amd64
-)
-
-// See golang.org/issue/30899.
-func adjustFreeBSD32(m *socket.Message) {
-	// FreeBSD 12.0-RELEASE is affected by https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=236737
-	if 1200086 <= freebsdVersion && freebsdVersion < 1201000 {
-		l := (m.NN + 4 - 1) &^ (4 - 1)
-		if m.NN < l && l <= len(m.OOB) {
-			m.NN = l
-		}
-	}
-}
-
-func boolint(b bool) int {
-	if b {
-		return 1
-	}
-	return 0
-}
-
-func netAddrToIP4(a net.Addr) net.IP {
-	switch v := a.(type) {
-	case *net.UDPAddr:
-		if ip := v.IP.To4(); ip != nil {
-			return ip
-		}
-	case *net.IPAddr:
-		if ip := v.IP.To4(); ip != nil {
-			return ip
-		}
-	}
-	return nil
-}
-
-func opAddr(a net.Addr) net.Addr {
-	switch a.(type) {
-	case *net.TCPAddr:
-		if a == nil {
-			return nil
-		}
-	case *net.UDPAddr:
-		if a == nil {
-			return nil
-		}
-	case *net.IPAddr:
-		if a == nil {
-			return nil
-		}
-	}
-	return a
-}