case <-up:
	}
	t.Cleanup(func() { _ = server.Shutdown() })
	server.Addr = server.PacketConn.LocalAddr().String()

	select {
	case <-time.After(time.Second * 10):
		t.Fatalf("setup timeout")
	case <-up:
	}
	t.Cleanup(func() { _ = tcp.Shutdown() })
	t.Cleanup(func() { _ = server.Shutdown() })
	tcp.Addr = server.PacketConn.LocalAddr().String()
	return server.Addr
}

	if err != nil {
		err = &OpError{Op: "file", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
	}
	return
}

// PacketConn is a generic packet-oriented network connection.
//
// Multiple goroutines may invoke methods on a PacketConn simultaneously.
type PacketConn interface {
	// ReadFrom reads a packet from the connection,
	// copying the payload into p. It returns the number of

// loopback IP address or local file system path.
//
// The provided network must be "udp", "udp4", "udp6" or "unixgram".
func NewLocalPacketListener(network string) (net.PacketConn, error) {
	stackOnce.Do(probeStack)
	switch network {
	case "udp":
		if canListenTCP4OnLoopback {
			if c, err := net.ListenPacket("udp4", "127.0.0.1:0"); err == nil {
				return c, nil
			}
		}

//go:build !windows && !plan9 && !js && !wasip1

package syslog

import (
	"bufio"
	"fmt"
	"io"
	"net"
	"os"
	"path/filepath"
	"runtime"
	"sync"
	"testing"
	"time"
)

func runPktSyslog(c net.PacketConn, done chan<- string) {
	var buf [4096]byte
	var rcvd string
	ct := 0
	for {
		var n int
		var err error

		c.SetReadDeadline(time.Now().Add(100 * time.Millisecond))
		n, _, err = c.ReadFrom(buf[:])

		for i := 0; i < 5; i++ {
			cs, err := newDualStackPacketListener()
			if err != nil {
				t.Fatal(err)
			}
			port := cs[0].port()
			for _, c := range cs {
				c.Close()
			}
			var c1 PacketConn
			c1, firstErr = ListenPacket(tt.network1, JoinHostPort(tt.address1, port))
			if firstErr != nil {
				continue
			}
			if err := checkFirstListener(tt.network1, c1); err != nil {
				c1.Close()

			return dnsmessage.Parser{}, dnsmessage.Header{}, err
		}
		if d, ok := ctx.Deadline(); ok && !d.IsZero() {
			c.SetDeadline(d)
		}
		var p dnsmessage.Parser
		var h dnsmessage.Header
		if _, ok := c.(PacketConn); ok {
			p, h, err = dnsPacketRoundTrip(c, id, q, udpReq)
		} else {
			p, h, err = dnsStreamRoundTrip(c, id, q, tcpReq)
		}
		c.Close()
		if err != nil {

pkg go/types, method (*Var) Embedded() bool
pkg net, method (*ListenConfig) Listen(context.Context, string, string) (Listener, error)
pkg net, method (*ListenConfig) ListenPacket(context.Context, string, string) (PacketConn, error)
pkg net, type Dialer struct, Control func(string, string, syscall.RawConn) error
pkg net, type ListenConfig struct
pkg net, type ListenConfig struct, Control func(string, string, syscall.RawConn) error

	// always be a literal IP address and not a host name, and the
	// port in the address parameter will be a literal port number
	// and not a service name.
	// If the Conn returned is also a PacketConn, sent and received DNS
	// messages must adhere to RFC 1035 section 4.2.1, "UDP usage".
	// Otherwise, DNS messages transmitted over Conn must adhere
	// to RFC 7766 section 5, "Transport Protocol Selection".

	}
	return len(b), nil
}

func (f *fakeDNSConn) SetDeadline(t time.Time) error {
	f.t = t
	return nil
}

type fakeDNSPacketConn struct {
	PacketConn
	fakeDNSConn
}

func (f *fakeDNSPacketConn) SetDeadline(t time.Time) error {
	return f.fakeDNSConn.SetDeadline(t)
}

func (f *fakeDNSPacketConn) Close() error {
	return f.fakeDNSConn.Close()
}

pkg net, type OpError struct, Op string
pkg net, type PacketConn interface { Close, LocalAddr, ReadFrom, SetDeadline, SetReadDeadline, SetWriteDeadline, WriteTo }
pkg net, type PacketConn interface, Close() error
pkg net, type PacketConn interface, LocalAddr() Addr
pkg net, type PacketConn interface, ReadFrom([]uint8) (int, Addr, error)
pkg net, type PacketConn interface, SetDeadline(time.Time) error