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|
// Copyright 2020 The gVisor Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package testbench has utilities to send and receive packets and also command
// the DUT to run POSIX functions.
package testbench
import (
"fmt"
"math/rand"
"net"
"testing"
"time"
"github.com/mohae/deepcopy"
"go.uber.org/multierr"
"golang.org/x/sys/unix"
"gvisor.dev/gvisor/pkg/tcpip"
"gvisor.dev/gvisor/pkg/tcpip/header"
"gvisor.dev/gvisor/pkg/tcpip/seqnum"
)
func portFromSockaddr(sa unix.Sockaddr) (uint16, error) {
switch sa := sa.(type) {
case *unix.SockaddrInet4:
return uint16(sa.Port), nil
case *unix.SockaddrInet6:
return uint16(sa.Port), nil
}
return 0, fmt.Errorf("sockaddr type %T does not contain port", sa)
}
// pickPort makes a new socket and returns the socket FD and port. The domain should be AF_INET or AF_INET6. The caller must close the FD when done with
// the port if there is no error.
func pickPort(domain, typ int) (fd int, sa unix.Sockaddr, err error) {
fd, err = unix.Socket(domain, typ, 0)
if err != nil {
return -1, nil, err
}
defer func() {
if err != nil {
err = multierr.Append(err, unix.Close(fd))
}
}()
switch domain {
case unix.AF_INET:
var sa4 unix.SockaddrInet4
copy(sa4.Addr[:], net.ParseIP(LocalIPv4).To4())
sa = &sa4
case unix.AF_INET6:
var sa6 unix.SockaddrInet6
copy(sa6.Addr[:], net.ParseIP(LocalIPv6).To16())
sa = &sa6
default:
return -1, nil, fmt.Errorf("invalid domain %d, it should be one of unix.AF_INET or unix.AF_INET6", domain)
}
if err = unix.Bind(fd, sa); err != nil {
return -1, nil, err
}
sa, err = unix.Getsockname(fd)
if err != nil {
return -1, nil, err
}
return fd, sa, nil
}
// layerState stores the state of a layer of a connection.
type layerState interface {
// outgoing returns an outgoing layer to be sent in a frame. It should not
// update layerState, that is done in layerState.sent.
outgoing() Layer
// incoming creates an expected Layer for comparing against a received Layer.
// Because the expectation can depend on values in the received Layer, it is
// an input to incoming. For example, the ACK number needs to be checked in a
// TCP packet but only if the ACK flag is set in the received packet. It
// should not update layerState, that is done in layerState.received. The
// caller takes ownership of the returned Layer.
incoming(received Layer) Layer
// sent updates the layerState based on the Layer that was sent. The input is
// a Layer with all prev and next pointers populated so that the entire frame
// as it was sent is available.
sent(sent Layer) error
// received updates the layerState based on a Layer that is receieved. The
// input is a Layer with all prev and next pointers populated so that the
// entire frame as it was receieved is available.
received(received Layer) error
// close frees associated resources held by the LayerState.
close() error
}
// etherState maintains state about an Ethernet connection.
type etherState struct {
out, in Ether
}
var _ layerState = (*etherState)(nil)
// newEtherState creates a new etherState.
func newEtherState(out, in Ether) (*etherState, error) {
lMAC, err := tcpip.ParseMACAddress(LocalMAC)
if err != nil {
return nil, fmt.Errorf("parsing local MAC: %q: %w", LocalMAC, err)
}
rMAC, err := tcpip.ParseMACAddress(RemoteMAC)
if err != nil {
return nil, fmt.Errorf("parsing remote MAC: %q: %w", RemoteMAC, err)
}
s := etherState{
out: Ether{SrcAddr: &lMAC, DstAddr: &rMAC},
in: Ether{SrcAddr: &rMAC, DstAddr: &lMAC},
}
if err := s.out.merge(&out); err != nil {
return nil, err
}
if err := s.in.merge(&in); err != nil {
return nil, err
}
return &s, nil
}
func (s *etherState) outgoing() Layer {
return deepcopy.Copy(&s.out).(Layer)
}
// incoming implements layerState.incoming.
func (s *etherState) incoming(Layer) Layer {
return deepcopy.Copy(&s.in).(Layer)
}
func (*etherState) sent(Layer) error {
return nil
}
func (*etherState) received(Layer) error {
return nil
}
func (*etherState) close() error {
return nil
}
// ipv4State maintains state about an IPv4 connection.
type ipv4State struct {
out, in IPv4
}
var _ layerState = (*ipv4State)(nil)
// newIPv4State creates a new ipv4State.
func newIPv4State(out, in IPv4) (*ipv4State, error) {
lIP := tcpip.Address(net.ParseIP(LocalIPv4).To4())
rIP := tcpip.Address(net.ParseIP(RemoteIPv4).To4())
s := ipv4State{
out: IPv4{SrcAddr: &lIP, DstAddr: &rIP},
in: IPv4{SrcAddr: &rIP, DstAddr: &lIP},
}
if err := s.out.merge(&out); err != nil {
return nil, err
}
if err := s.in.merge(&in); err != nil {
return nil, err
}
return &s, nil
}
func (s *ipv4State) outgoing() Layer {
return deepcopy.Copy(&s.out).(Layer)
}
// incoming implements layerState.incoming.
func (s *ipv4State) incoming(Layer) Layer {
return deepcopy.Copy(&s.in).(Layer)
}
func (*ipv4State) sent(Layer) error {
return nil
}
func (*ipv4State) received(Layer) error {
return nil
}
func (*ipv4State) close() error {
return nil
}
// ipv6State maintains state about an IPv6 connection.
type ipv6State struct {
out, in IPv6
}
var _ layerState = (*ipv6State)(nil)
// newIPv6State creates a new ipv6State.
func newIPv6State(out, in IPv6) (*ipv6State, error) {
lIP := tcpip.Address(net.ParseIP(LocalIPv6).To16())
rIP := tcpip.Address(net.ParseIP(RemoteIPv6).To16())
s := ipv6State{
out: IPv6{SrcAddr: &lIP, DstAddr: &rIP},
in: IPv6{SrcAddr: &rIP, DstAddr: &lIP},
}
if err := s.out.merge(&out); err != nil {
return nil, err
}
if err := s.in.merge(&in); err != nil {
return nil, err
}
return &s, nil
}
// outgoing returns an outgoing layer to be sent in a frame.
func (s *ipv6State) outgoing() Layer {
return deepcopy.Copy(&s.out).(Layer)
}
func (s *ipv6State) incoming(Layer) Layer {
return deepcopy.Copy(&s.in).(Layer)
}
func (s *ipv6State) sent(Layer) error {
// Nothing to do.
return nil
}
func (s *ipv6State) received(Layer) error {
// Nothing to do.
return nil
}
// close cleans up any resources held.
func (s *ipv6State) close() error {
return nil
}
// tcpState maintains state about a TCP connection.
type tcpState struct {
out, in TCP
localSeqNum, remoteSeqNum *seqnum.Value
synAck *TCP
portPickerFD int
finSent bool
}
var _ layerState = (*tcpState)(nil)
// SeqNumValue is a helper routine that allocates a new seqnum.Value value to
// store v and returns a pointer to it.
func SeqNumValue(v seqnum.Value) *seqnum.Value {
return &v
}
// newTCPState creates a new TCPState.
func newTCPState(domain int, out, in TCP) (*tcpState, error) {
portPickerFD, localAddr, err := pickPort(domain, unix.SOCK_STREAM)
if err != nil {
return nil, err
}
localPort, err := portFromSockaddr(localAddr)
if err != nil {
return nil, err
}
s := tcpState{
out: TCP{SrcPort: &localPort},
in: TCP{DstPort: &localPort},
localSeqNum: SeqNumValue(seqnum.Value(rand.Uint32())),
portPickerFD: portPickerFD,
finSent: false,
}
if err := s.out.merge(&out); err != nil {
return nil, err
}
if err := s.in.merge(&in); err != nil {
return nil, err
}
return &s, nil
}
func (s *tcpState) outgoing() Layer {
newOutgoing := deepcopy.Copy(s.out).(TCP)
if s.localSeqNum != nil {
newOutgoing.SeqNum = Uint32(uint32(*s.localSeqNum))
}
if s.remoteSeqNum != nil {
newOutgoing.AckNum = Uint32(uint32(*s.remoteSeqNum))
}
return &newOutgoing
}
// incoming implements layerState.incoming.
func (s *tcpState) incoming(received Layer) Layer {
tcpReceived, ok := received.(*TCP)
if !ok {
return nil
}
newIn := deepcopy.Copy(s.in).(TCP)
if s.remoteSeqNum != nil {
newIn.SeqNum = Uint32(uint32(*s.remoteSeqNum))
}
if s.localSeqNum != nil && (*tcpReceived.Flags&header.TCPFlagAck) != 0 {
// The caller didn't specify an AckNum so we'll expect the calculated one,
// but only if the ACK flag is set because the AckNum is not valid in a
// header if ACK is not set.
newIn.AckNum = Uint32(uint32(*s.localSeqNum))
}
return &newIn
}
func (s *tcpState) sent(sent Layer) error {
tcp, ok := sent.(*TCP)
if !ok {
return fmt.Errorf("can't update tcpState with %T Layer", sent)
}
if !s.finSent {
// update localSeqNum by the payload only when FIN is not yet sent by us
for current := tcp.next(); current != nil; current = current.next() {
s.localSeqNum.UpdateForward(seqnum.Size(current.length()))
}
}
if tcp.Flags != nil && *tcp.Flags&(header.TCPFlagSyn|header.TCPFlagFin) != 0 {
s.localSeqNum.UpdateForward(1)
}
if *tcp.Flags&(header.TCPFlagFin) != 0 {
s.finSent = true
}
return nil
}
func (s *tcpState) received(l Layer) error {
tcp, ok := l.(*TCP)
if !ok {
return fmt.Errorf("can't update tcpState with %T Layer", l)
}
s.remoteSeqNum = SeqNumValue(seqnum.Value(*tcp.SeqNum))
if *tcp.Flags&(header.TCPFlagSyn|header.TCPFlagFin) != 0 {
s.remoteSeqNum.UpdateForward(1)
}
for current := tcp.next(); current != nil; current = current.next() {
s.remoteSeqNum.UpdateForward(seqnum.Size(current.length()))
}
return nil
}
// close frees the port associated with this connection.
func (s *tcpState) close() error {
if err := unix.Close(s.portPickerFD); err != nil {
return err
}
s.portPickerFD = -1
return nil
}
// udpState maintains state about a UDP connection.
type udpState struct {
out, in UDP
portPickerFD int
}
var _ layerState = (*udpState)(nil)
// newUDPState creates a new udpState.
func newUDPState(domain int, out, in UDP) (*udpState, unix.Sockaddr, error) {
portPickerFD, localAddr, err := pickPort(domain, unix.SOCK_DGRAM)
if err != nil {
return nil, nil, err
}
localPort, err := portFromSockaddr(localAddr)
if err != nil {
return nil, nil, err
}
s := udpState{
out: UDP{SrcPort: &localPort},
in: UDP{DstPort: &localPort},
portPickerFD: portPickerFD,
}
if err := s.out.merge(&out); err != nil {
return nil, nil, err
}
if err := s.in.merge(&in); err != nil {
return nil, nil, err
}
return &s, localAddr, nil
}
func (s *udpState) outgoing() Layer {
return deepcopy.Copy(&s.out).(Layer)
}
// incoming implements layerState.incoming.
func (s *udpState) incoming(Layer) Layer {
return deepcopy.Copy(&s.in).(Layer)
}
func (*udpState) sent(l Layer) error {
return nil
}
func (*udpState) received(l Layer) error {
return nil
}
// close frees the port associated with this connection.
func (s *udpState) close() error {
if err := unix.Close(s.portPickerFD); err != nil {
return err
}
s.portPickerFD = -1
return nil
}
// Connection holds a collection of layer states for maintaining a connection
// along with sockets for sniffer and injecting packets.
type Connection struct {
layerStates []layerState
injector Injector
sniffer Sniffer
localAddr unix.Sockaddr
t *testing.T
}
// Returns the default incoming frame against which to match. If received is
// longer than layerStates then that may still count as a match. The reverse is
// never a match and nil is returned.
func (conn *Connection) incoming(received Layers) Layers {
if len(received) < len(conn.layerStates) {
return nil
}
in := Layers{}
for i, s := range conn.layerStates {
toMatch := s.incoming(received[i])
if toMatch == nil {
return nil
}
in = append(in, toMatch)
}
return in
}
func (conn *Connection) match(override, received Layers) bool {
toMatch := conn.incoming(received)
if toMatch == nil {
return false // Not enough layers in gotLayers for matching.
}
if err := toMatch.merge(override); err != nil {
return false // Failing to merge is not matching.
}
return toMatch.match(received)
}
// Close frees associated resources held by the Connection.
func (conn *Connection) Close() {
errs := multierr.Combine(conn.sniffer.close(), conn.injector.close())
for _, s := range conn.layerStates {
if err := s.close(); err != nil {
errs = multierr.Append(errs, fmt.Errorf("unable to close %+v: %s", s, err))
}
}
if errs != nil {
conn.t.Fatalf("unable to close %+v: %s", conn, errs)
}
}
// CreateFrame builds a frame for the connection with layer overriding defaults
// of the innermost layer and additionalLayers added after it.
func (conn *Connection) CreateFrame(layer Layer, additionalLayers ...Layer) Layers {
var layersToSend Layers
for _, s := range conn.layerStates {
layersToSend = append(layersToSend, s.outgoing())
}
if err := layersToSend[len(layersToSend)-1].merge(layer); err != nil {
conn.t.Fatalf("can't merge %+v into %+v: %s", layer, layersToSend[len(layersToSend)-1], err)
}
layersToSend = append(layersToSend, additionalLayers...)
return layersToSend
}
// SendFrame sends a frame on the wire and updates the state of all layers.
func (conn *Connection) SendFrame(frame Layers) {
outBytes, err := frame.ToBytes()
if err != nil {
conn.t.Fatalf("can't build outgoing packet: %s", err)
}
conn.injector.Send(outBytes)
// frame might have nil values where the caller wanted to use default values.
// sentFrame will have no nil values in it because it comes from parsing the
// bytes that were actually sent.
sentFrame := parse(parseEther, outBytes)
// Update the state of each layer based on what was sent.
for i, s := range conn.layerStates {
if err := s.sent(sentFrame[i]); err != nil {
conn.t.Fatalf("Unable to update the state of %+v with %s: %s", s, sentFrame[i], err)
}
}
}
// Send a packet with reasonable defaults. Potentially override the final layer
// in the connection with the provided layer and add additionLayers.
func (conn *Connection) Send(layer Layer, additionalLayers ...Layer) {
conn.SendFrame(conn.CreateFrame(layer, additionalLayers...))
}
// recvFrame gets the next successfully parsed frame (of type Layers) within the
// timeout provided. If no parsable frame arrives before the timeout, it returns
// nil.
func (conn *Connection) recvFrame(timeout time.Duration) Layers {
if timeout <= 0 {
return nil
}
b := conn.sniffer.Recv(timeout)
if b == nil {
return nil
}
return parse(parseEther, b)
}
// layersError stores the Layers that we got and the Layers that we wanted to
// match.
type layersError struct {
got, want Layers
}
func (e *layersError) Error() string {
return e.got.diff(e.want)
}
// Expect expects a frame with the final layerStates layer matching the
// provided Layer within the timeout specified. If it doesn't arrive in time,
// an error is returned.
func (conn *Connection) Expect(layer Layer, timeout time.Duration) (Layer, error) {
// Make a frame that will ignore all but the final layer.
layers := make([]Layer, len(conn.layerStates))
layers[len(layers)-1] = layer
gotFrame, err := conn.ExpectFrame(layers, timeout)
if err != nil {
return nil, err
}
if len(conn.layerStates)-1 < len(gotFrame) {
return gotFrame[len(conn.layerStates)-1], nil
}
conn.t.Fatal("the received frame should be at least as long as the expected layers")
panic("unreachable")
}
// ExpectFrame expects a frame that matches the provided Layers within the
// timeout specified. If one arrives in time, the Layers is returned without an
// error. If it doesn't arrive in time, it returns nil and error is non-nil.
func (conn *Connection) ExpectFrame(layers Layers, timeout time.Duration) (Layers, error) {
deadline := time.Now().Add(timeout)
var errs error
for {
var gotLayers Layers
if timeout = time.Until(deadline); timeout > 0 {
gotLayers = conn.recvFrame(timeout)
}
if gotLayers == nil {
if errs == nil {
return nil, fmt.Errorf("got no frames matching %v during %s", layers, timeout)
}
return nil, fmt.Errorf("got no frames matching %v during %s: got %w", layers, timeout, errs)
}
if conn.match(layers, gotLayers) {
for i, s := range conn.layerStates {
if err := s.received(gotLayers[i]); err != nil {
conn.t.Fatal(err)
}
}
return gotLayers, nil
}
errs = multierr.Combine(errs, &layersError{got: gotLayers, want: conn.incoming(gotLayers)})
}
}
// Drain drains the sniffer's receive buffer by receiving packets until there's
// nothing else to receive.
func (conn *Connection) Drain() {
conn.sniffer.Drain()
}
// TCPIPv4 maintains the state for all the layers in a TCP/IPv4 connection.
type TCPIPv4 Connection
// NewTCPIPv4 creates a new TCPIPv4 connection with reasonable defaults.
func NewTCPIPv4(t *testing.T, outgoingTCP, incomingTCP TCP) TCPIPv4 {
etherState, err := newEtherState(Ether{}, Ether{})
if err != nil {
t.Fatalf("can't make etherState: %s", err)
}
ipv4State, err := newIPv4State(IPv4{}, IPv4{})
if err != nil {
t.Fatalf("can't make ipv4State: %s", err)
}
tcpState, err := newTCPState(unix.AF_INET, outgoingTCP, incomingTCP)
if err != nil {
t.Fatalf("can't make tcpState: %s", err)
}
injector, err := NewInjector(t)
if err != nil {
t.Fatalf("can't make injector: %s", err)
}
sniffer, err := NewSniffer(t)
if err != nil {
t.Fatalf("can't make sniffer: %s", err)
}
return TCPIPv4{
layerStates: []layerState{etherState, ipv4State, tcpState},
injector: injector,
sniffer: sniffer,
t: t,
}
}
// Handshake performs a TCP 3-way handshake. The input Connection should have a
// final TCP Layer.
func (conn *TCPIPv4) Handshake() {
// Send the SYN.
conn.Send(TCP{Flags: Uint8(header.TCPFlagSyn)})
// Wait for the SYN-ACK.
synAck, err := conn.Expect(TCP{Flags: Uint8(header.TCPFlagSyn | header.TCPFlagAck)}, time.Second)
if synAck == nil {
conn.t.Fatalf("didn't get synack during handshake: %s", err)
}
conn.layerStates[len(conn.layerStates)-1].(*tcpState).synAck = synAck
// Send an ACK.
conn.Send(TCP{Flags: Uint8(header.TCPFlagAck)})
}
// ExpectData is a convenient method that expects a Layer and the Layer after
// it. If it doens't arrive in time, it returns nil.
func (conn *TCPIPv4) ExpectData(tcp *TCP, payload *Payload, timeout time.Duration) (Layers, error) {
expected := make([]Layer, len(conn.layerStates))
expected[len(expected)-1] = tcp
if payload != nil {
expected = append(expected, payload)
}
return (*Connection)(conn).ExpectFrame(expected, timeout)
}
// Send a packet with reasonable defaults. Potentially override the TCP layer in
// the connection with the provided layer and add additionLayers.
func (conn *TCPIPv4) Send(tcp TCP, additionalLayers ...Layer) {
(*Connection)(conn).Send(&tcp, additionalLayers...)
}
// Close frees associated resources held by the TCPIPv4 connection.
func (conn *TCPIPv4) Close() {
(*Connection)(conn).Close()
}
// Expect expects a frame with the TCP layer matching the provided TCP within
// the timeout specified. If it doesn't arrive in time, an error is returned.
func (conn *TCPIPv4) Expect(tcp TCP, timeout time.Duration) (*TCP, error) {
layer, err := (*Connection)(conn).Expect(&tcp, timeout)
if layer == nil {
return nil, err
}
gotTCP, ok := layer.(*TCP)
if !ok {
conn.t.Fatalf("expected %s to be TCP", layer)
}
return gotTCP, err
}
func (conn *TCPIPv4) state() *tcpState {
state, ok := conn.layerStates[len(conn.layerStates)-1].(*tcpState)
if !ok {
conn.t.Fatalf("expected final state of %v to be tcpState", conn.layerStates)
}
return state
}
// RemoteSeqNum returns the next expected sequence number from the DUT.
func (conn *TCPIPv4) RemoteSeqNum() *seqnum.Value {
return conn.state().remoteSeqNum
}
// LocalSeqNum returns the next sequence number to send from the testbench.
func (conn *TCPIPv4) LocalSeqNum() *seqnum.Value {
return conn.state().localSeqNum
}
// SynAck returns the SynAck that was part of the handshake.
func (conn *TCPIPv4) SynAck() *TCP {
return conn.state().synAck
}
// IPv6Conn maintains the state for all the layers in a IPv6 connection.
type IPv6Conn Connection
// NewIPv6Conn creates a new IPv6Conn connection with reasonable defaults.
func NewIPv6Conn(t *testing.T, outgoingIPv6, incomingIPv6 IPv6) IPv6Conn {
etherState, err := newEtherState(Ether{}, Ether{})
if err != nil {
t.Fatalf("can't make EtherState: %s", err)
}
ipv6State, err := newIPv6State(outgoingIPv6, incomingIPv6)
if err != nil {
t.Fatalf("can't make IPv6State: %s", err)
}
injector, err := NewInjector(t)
if err != nil {
t.Fatalf("can't make injector: %s", err)
}
sniffer, err := NewSniffer(t)
if err != nil {
t.Fatalf("can't make sniffer: %s", err)
}
return IPv6Conn{
layerStates: []layerState{etherState, ipv6State},
injector: injector,
sniffer: sniffer,
t: t,
}
}
// SendFrame sends a frame on the wire and updates the state of all layers.
func (conn *IPv6Conn) SendFrame(frame Layers) {
(*Connection)(conn).SendFrame(frame)
}
// CreateFrame builds a frame for the connection with ipv6 overriding the ipv6
// layer defaults and additionalLayers added after it.
func (conn *IPv6Conn) CreateFrame(ipv6 IPv6, additionalLayers ...Layer) Layers {
return (*Connection)(conn).CreateFrame(&ipv6, additionalLayers...)
}
// Close to clean up any resources held.
func (conn *IPv6Conn) Close() {
(*Connection)(conn).Close()
}
// ExpectFrame expects a frame that matches the provided Layers within the
// timeout specified. If it doesn't arrive in time, an error is returned.
func (conn *IPv6Conn) ExpectFrame(frame Layers, timeout time.Duration) (Layers, error) {
return (*Connection)(conn).ExpectFrame(frame, timeout)
}
// Drain drains the sniffer's receive buffer by receiving packets until there's
// nothing else to receive.
func (conn *TCPIPv4) Drain() {
conn.sniffer.Drain()
}
// UDPIPv4 maintains the state for all the layers in a UDP/IPv4 connection.
type UDPIPv4 Connection
// NewUDPIPv4 creates a new UDPIPv4 connection with reasonable defaults.
func NewUDPIPv4(t *testing.T, outgoingUDP, incomingUDP UDP) UDPIPv4 {
etherState, err := newEtherState(Ether{}, Ether{})
if err != nil {
t.Fatalf("can't make etherState: %s", err)
}
ipv4State, err := newIPv4State(IPv4{}, IPv4{})
if err != nil {
t.Fatalf("can't make ipv4State: %s", err)
}
udpState, localAddr, err := newUDPState(unix.AF_INET, outgoingUDP, incomingUDP)
if err != nil {
t.Fatalf("can't make udpState: %s", err)
}
injector, err := NewInjector(t)
if err != nil {
t.Fatalf("can't make injector: %s", err)
}
sniffer, err := NewSniffer(t)
if err != nil {
t.Fatalf("can't make sniffer: %s", err)
}
return UDPIPv4{
layerStates: []layerState{etherState, ipv4State, udpState},
injector: injector,
sniffer: sniffer,
localAddr: localAddr,
t: t,
}
}
// LocalAddr gets the local socket address of this connection.
func (conn *UDPIPv4) LocalAddr() unix.Sockaddr {
return conn.localAddr
}
// CreateFrame builds a frame for the connection with layer overriding defaults
// of the innermost layer and additionalLayers added after it.
func (conn *UDPIPv4) CreateFrame(layer Layer, additionalLayers ...Layer) Layers {
return (*Connection)(conn).CreateFrame(layer, additionalLayers...)
}
// Send a packet with reasonable defaults. Potentially override the UDP layer in
// the connection with the provided layer and add additionLayers.
func (conn *UDPIPv4) Send(udp UDP, additionalLayers ...Layer) {
(*Connection)(conn).Send(&udp, additionalLayers...)
}
// SendFrame sends a frame on the wire and updates the state of all layers.
func (conn *UDPIPv4) SendFrame(frame Layers) {
(*Connection)(conn).SendFrame(frame)
}
// SendIP sends a packet with additionalLayers following the IP layer in the
// connection.
func (conn *UDPIPv4) SendIP(additionalLayers ...Layer) {
var layersToSend Layers
for _, s := range conn.layerStates[:len(conn.layerStates)-1] {
layersToSend = append(layersToSend, s.outgoing())
}
layersToSend = append(layersToSend, additionalLayers...)
conn.SendFrame(layersToSend)
}
// Expect expects a frame with the UDP layer matching the provided UDP within
// the timeout specified. If it doesn't arrive in time, an error is returned.
func (conn *UDPIPv4) Expect(udp UDP, timeout time.Duration) (*UDP, error) {
conn.t.Helper()
layer, err := (*Connection)(conn).Expect(&udp, timeout)
if layer == nil {
return nil, err
}
gotUDP, ok := layer.(*UDP)
if !ok {
conn.t.Fatalf("expected %s to be UDP", layer)
}
return gotUDP, err
}
// ExpectData is a convenient method that expects a Layer and the Layer after
// it. If it doens't arrive in time, it returns nil.
func (conn *UDPIPv4) ExpectData(udp UDP, payload Payload, timeout time.Duration) (Layers, error) {
conn.t.Helper()
expected := make([]Layer, len(conn.layerStates))
expected[len(expected)-1] = &udp
if payload.length() != 0 {
expected = append(expected, &payload)
}
return (*Connection)(conn).ExpectFrame(expected, timeout)
}
// Close frees associated resources held by the UDPIPv4 connection.
func (conn *UDPIPv4) Close() {
(*Connection)(conn).Close()
}
// Drain drains the sniffer's receive buffer by receiving packets until there's
// nothing else to receive.
func (conn *UDPIPv4) Drain() {
conn.sniffer.Drain()
}
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