Add support for ping sockets

PiperOrigin-RevId: 195049322
Change-Id: I09f6dd58cf10a2e50e53d17d2823d540102913c5

3 files changed, 12 insertions, 319 deletions

diff --git a/pkg/tcpip/network/ipv4/BUILD b/pkg/tcpip/network/ipv4/BUILD
index 9df113df1..02d55355c 100644
--- a/pkg/tcpip/network/ipv4/BUILD
+++ b/pkg/tcpip/network/ipv4/BUILD
@@ -1,6 +1,6 @@
 package(licenses = ["notice"])  # BSD
 
-load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
 
 go_library(
     name = "ipv4",
@@ -19,20 +19,5 @@ go_library(
         "//pkg/tcpip/network/fragmentation",
         "//pkg/tcpip/network/hash",
         "//pkg/tcpip/stack",
-        "//pkg/waiter",
-    ],
-)
-
-go_test(
-    name = "ipv4_test",
-    size = "small",
-    srcs = ["icmp_test.go"],
-    deps = [
-        ":ipv4",
-        "//pkg/tcpip",
-        "//pkg/tcpip/buffer",
-        "//pkg/tcpip/link/channel",
-        "//pkg/tcpip/link/sniffer",
-        "//pkg/tcpip/stack",
     ],
 )
diff --git a/pkg/tcpip/network/ipv4/icmp.go b/pkg/tcpip/network/ipv4/icmp.go
index ffd761350..3c382fdc2 100644
--- a/pkg/tcpip/network/ipv4/icmp.go
+++ b/pkg/tcpip/network/ipv4/icmp.go
@@ -5,26 +5,14 @@
 package ipv4
 
 import (
-	"context"
 	"encoding/binary"
-	"time"
 
 	"gvisor.googlesource.com/gvisor/pkg/tcpip"
 	"gvisor.googlesource.com/gvisor/pkg/tcpip/buffer"
 	"gvisor.googlesource.com/gvisor/pkg/tcpip/header"
 	"gvisor.googlesource.com/gvisor/pkg/tcpip/stack"
-	"gvisor.googlesource.com/gvisor/pkg/waiter"
 )
 
-// PingProtocolName is a pseudo transport protocol used to handle ping replies.
-// Use it when constructing a stack that intends to use ipv4.Ping.
-const PingProtocolName = "icmpv4ping"
-
-// pingProtocolNumber is a fake transport protocol used to
-// deliver incoming ICMP echo replies. The ICMP identifier
-// number is used as a port number for multiplexing.
-const pingProtocolNumber tcpip.TransportProtocolNumber = 256 + 11
-
 // handleControl handles the case when an ICMP packet contains the headers of
 // the original packet that caused the ICMP one to be sent. This information is
 // used to find out which transport endpoint must be notified about the ICMP
@@ -78,7 +66,10 @@ func (e *endpoint) handleICMP(r *stack.Route, vv *buffer.VectorisedView) {
 		}
 
 	case header.ICMPv4EchoReply:
-		e.dispatcher.DeliverTransportPacket(r, pingProtocolNumber, vv)
+		if len(v) < header.ICMPv4EchoMinimumSize {
+			return
+		}
+		e.dispatcher.DeliverTransportPacket(r, header.ICMPv4ProtocolNumber, vv)
 
 	case header.ICMPv4DstUnreachable:
 		if len(v) < header.ICMPv4DstUnreachableMinimumSize {
@@ -104,179 +95,20 @@ type echoRequest struct {
 
 func (e *endpoint) echoReplier() {
 	for req := range e.echoRequests {
-		sendICMPv4(&req.r, header.ICMPv4EchoReply, 0, req.v)
+		sendPing4(&req.r, 0, req.v)
 		req.r.Release()
 	}
 }
 
-func sendICMPv4(r *stack.Route, typ header.ICMPv4Type, code byte, data buffer.View) *tcpip.Error {
-	hdr := buffer.NewPrependable(header.ICMPv4MinimumSize + int(r.MaxHeaderLength()))
+func sendPing4(r *stack.Route, code byte, data buffer.View) *tcpip.Error {
+	hdr := buffer.NewPrependable(header.ICMPv4EchoMinimumSize + int(r.MaxHeaderLength()))
 
-	icmpv4 := header.ICMPv4(hdr.Prepend(header.ICMPv4MinimumSize))
-	icmpv4.SetType(typ)
+	icmpv4 := header.ICMPv4(hdr.Prepend(header.ICMPv4EchoMinimumSize))
+	icmpv4.SetType(header.ICMPv4EchoReply)
 	icmpv4.SetCode(code)
+	copy(icmpv4[header.ICMPv4MinimumSize:], data)
+	data = data[header.ICMPv4EchoMinimumSize-header.ICMPv4MinimumSize:]
 	icmpv4.SetChecksum(^header.Checksum(icmpv4, header.Checksum(data, 0)))
 
 	return r.WritePacket(&hdr, data, header.ICMPv4ProtocolNumber)
 }
-
-// A Pinger can send echo requests to an address.
-type Pinger struct {
-	Stack     *stack.Stack
-	NICID     tcpip.NICID
-	Addr      tcpip.Address
-	LocalAddr tcpip.Address // optional
-	Wait      time.Duration // if zero, defaults to 1 second
-	Count     uint16        // if zero, defaults to MaxUint16
-}
-
-// Ping sends echo requests to an ICMPv4 endpoint.
-// Responses are streamed to the channel ch.
-func (p *Pinger) Ping(ctx context.Context, ch chan<- PingReply) *tcpip.Error {
-	count := p.Count
-	if count == 0 {
-		count = 1<<16 - 1
-	}
-	wait := p.Wait
-	if wait == 0 {
-		wait = 1 * time.Second
-	}
-
-	r, err := p.Stack.FindRoute(p.NICID, p.LocalAddr, p.Addr, ProtocolNumber)
-	if err != nil {
-		return err
-	}
-
-	netProtos := []tcpip.NetworkProtocolNumber{ProtocolNumber}
-	ep := &pingEndpoint{
-		stack: p.Stack,
-		pktCh: make(chan buffer.View, 1),
-	}
-	id := stack.TransportEndpointID{
-		LocalAddress:  r.LocalAddress,
-		RemoteAddress: p.Addr,
-	}
-
-	_, err = p.Stack.PickEphemeralPort(func(port uint16) (bool, *tcpip.Error) {
-		id.LocalPort = port
-		err := p.Stack.RegisterTransportEndpoint(p.NICID, netProtos, pingProtocolNumber, id, ep)
-		switch err {
-		case nil:
-			return true, nil
-		case tcpip.ErrPortInUse:
-			return false, nil
-		default:
-			return false, err
-		}
-	})
-	if err != nil {
-		return err
-	}
-	defer p.Stack.UnregisterTransportEndpoint(p.NICID, netProtos, pingProtocolNumber, id)
-
-	v := buffer.NewView(4)
-	binary.BigEndian.PutUint16(v[0:], id.LocalPort)
-
-	start := time.Now()
-
-	done := make(chan struct{})
-	go func(count int) {
-	loop:
-		for ; count > 0; count-- {
-			select {
-			case v := <-ep.pktCh:
-				seq := binary.BigEndian.Uint16(v[header.ICMPv4MinimumSize+2:])
-				ch <- PingReply{
-					Duration:  time.Since(start) - time.Duration(seq)*wait,
-					SeqNumber: seq,
-				}
-			case <-ctx.Done():
-				break loop
-			}
-		}
-		close(done)
-	}(int(count))
-	defer func() { <-done }()
-
-	t := time.NewTicker(wait)
-	defer t.Stop()
-	for seq := uint16(0); seq < count; seq++ {
-		select {
-		case <-t.C:
-		case <-ctx.Done():
-			return nil
-		}
-		binary.BigEndian.PutUint16(v[2:], seq)
-		sent := time.Now()
-		if err := sendICMPv4(&r, header.ICMPv4Echo, 0, v); err != nil {
-			ch <- PingReply{
-				Error:     err,
-				Duration:  time.Since(sent),
-				SeqNumber: seq,
-			}
-		}
-	}
-	return nil
-}
-
-// PingReply summarizes an ICMP echo reply.
-type PingReply struct {
-	Error     *tcpip.Error // reports any errors sending a ping request
-	Duration  time.Duration
-	SeqNumber uint16
-}
-
-type pingProtocol struct{}
-
-func (*pingProtocol) NewEndpoint(stack *stack.Stack, netProto tcpip.NetworkProtocolNumber, waiterQueue *waiter.Queue) (tcpip.Endpoint, *tcpip.Error) {
-	return nil, tcpip.ErrNotSupported // endpoints are created directly
-}
-
-func (*pingProtocol) Number() tcpip.TransportProtocolNumber { return pingProtocolNumber }
-
-func (*pingProtocol) MinimumPacketSize() int { return header.ICMPv4EchoMinimumSize }
-
-func (*pingProtocol) ParsePorts(v buffer.View) (src, dst uint16, err *tcpip.Error) {
-	ident := binary.BigEndian.Uint16(v[4:])
-	return 0, ident, nil
-}
-
-func (*pingProtocol) HandleUnknownDestinationPacket(*stack.Route, stack.TransportEndpointID, *buffer.VectorisedView) bool {
-	return true
-}
-
-// SetOption implements TransportProtocol.SetOption.
-func (p *pingProtocol) SetOption(option interface{}) *tcpip.Error {
-	return tcpip.ErrUnknownProtocolOption
-}
-
-// Option implements TransportProtocol.Option.
-func (p *pingProtocol) Option(option interface{}) *tcpip.Error {
-	return tcpip.ErrUnknownProtocolOption
-}
-
-func init() {
-	stack.RegisterTransportProtocolFactory(PingProtocolName, func() stack.TransportProtocol {
-		return &pingProtocol{}
-	})
-}
-
-type pingEndpoint struct {
-	stack *stack.Stack
-	pktCh chan buffer.View
-}
-
-func (e *pingEndpoint) Close() {
-	close(e.pktCh)
-}
-
-func (e *pingEndpoint) HandlePacket(r *stack.Route, id stack.TransportEndpointID, vv *buffer.VectorisedView) {
-	select {
-	case e.pktCh <- vv.ToView():
-	default:
-	}
-}
-
-// HandleControlPacket implements stack.TransportEndpoint.HandleControlPacket.
-func (e *pingEndpoint) HandleControlPacket(id stack.TransportEndpointID, typ stack.ControlType, extra uint32, vv *buffer.VectorisedView) {
-}
diff --git a/pkg/tcpip/network/ipv4/icmp_test.go b/pkg/tcpip/network/ipv4/icmp_test.go
deleted file mode 100644
index c55aa1835..000000000
--- a/pkg/tcpip/network/ipv4/icmp_test.go
+++ /dev/null
@@ -1,124 +0,0 @@
-// Copyright 2016 The Netstack 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_test
-
-import (
-	"context"
-	"testing"
-	"time"
-
-	"gvisor.googlesource.com/gvisor/pkg/tcpip"
-	"gvisor.googlesource.com/gvisor/pkg/tcpip/buffer"
-	"gvisor.googlesource.com/gvisor/pkg/tcpip/link/channel"
-	"gvisor.googlesource.com/gvisor/pkg/tcpip/link/sniffer"
-	"gvisor.googlesource.com/gvisor/pkg/tcpip/network/ipv4"
-	"gvisor.googlesource.com/gvisor/pkg/tcpip/stack"
-)
-
-const stackAddr = "\x0a\x00\x00\x01"
-
-type testContext struct {
-	t      *testing.T
-	linkEP *channel.Endpoint
-	s      *stack.Stack
-}
-
-func newTestContext(t *testing.T) *testContext {
-	s := stack.New(&tcpip.StdClock{}, []string{ipv4.ProtocolName}, []string{ipv4.PingProtocolName})
-
-	const defaultMTU = 65536
-	id, linkEP := channel.New(256, defaultMTU, "")
-	if testing.Verbose() {
-		id = sniffer.New(id)
-	}
-	if err := s.CreateNIC(1, id); err != nil {
-		t.Fatalf("CreateNIC failed: %v", err)
-	}
-
-	if err := s.AddAddress(1, ipv4.ProtocolNumber, stackAddr); err != nil {
-		t.Fatalf("AddAddress failed: %v", err)
-	}
-
-	s.SetRouteTable([]tcpip.Route{{
-		Destination: "\x00\x00\x00\x00",
-		Mask:        "\x00\x00\x00\x00",
-		Gateway:     "",
-		NIC:         1,
-	}})
-
-	return &testContext{
-		t:      t,
-		s:      s,
-		linkEP: linkEP,
-	}
-}
-
-func (c *testContext) cleanup() {
-	close(c.linkEP.C)
-}
-
-func (c *testContext) loopback() {
-	go func() {
-		for pkt := range c.linkEP.C {
-			v := make(buffer.View, len(pkt.Header)+len(pkt.Payload))
-			copy(v, pkt.Header)
-			copy(v[len(pkt.Header):], pkt.Payload)
-			vv := v.ToVectorisedView([1]buffer.View{})
-			c.linkEP.Inject(pkt.Proto, &vv)
-		}
-	}()
-}
-
-func TestEcho(t *testing.T) {
-	c := newTestContext(t)
-	defer c.cleanup()
-	c.loopback()
-
-	ch := make(chan ipv4.PingReply, 1)
-	p := ipv4.Pinger{
-		Stack: c.s,
-		NICID: 1,
-		Addr:  stackAddr,
-		Wait:  10 * time.Millisecond,
-		Count: 1, // one ping only
-	}
-	if err := p.Ping(context.Background(), ch); err != nil {
-		t.Fatalf("icmp.Ping failed: %v", err)
-	}
-
-	ping := <-ch
-	if ping.Error != nil {
-		t.Errorf("bad ping response: %v", ping.Error)
-	}
-}
-
-func TestEchoSequence(t *testing.T) {
-	c := newTestContext(t)
-	defer c.cleanup()
-	c.loopback()
-
-	const numPings = 3
-	ch := make(chan ipv4.PingReply, numPings)
-	p := ipv4.Pinger{
-		Stack: c.s,
-		NICID: 1,
-		Addr:  stackAddr,
-		Wait:  10 * time.Millisecond,
-		Count: numPings,
-	}
-	if err := p.Ping(context.Background(), ch); err != nil {
-		t.Fatalf("icmp.Ping failed: %v", err)
-	}
-
-	for i := uint16(0); i < numPings; i++ {
-		ping := <-ch
-		if ping.Error != nil {
-			t.Errorf("i=%d bad ping response: %v", i, ping.Error)
-		}
-		if ping.SeqNumber != i {
-			t.Errorf("SeqNumber=%d, want %d", ping.SeqNumber, i)
-		}
-	}
-}