gvisor.dev/gvisor@v0.0.0-20240520182842-f9d4d51c7e0f/test/packetimpact/tests/tcp_connect_icmp_error_test.go (about)

     1  // Copyright 2021 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package tcp_connect_icmp_error_test
    16  
    17  import (
    18  	"flag"
    19  	"testing"
    20  	"time"
    21  
    22  	"golang.org/x/sys/unix"
    23  	"gvisor.dev/gvisor/pkg/tcpip/header"
    24  	"gvisor.dev/gvisor/test/packetimpact/testbench"
    25  )
    26  
    27  func init() {
    28  	testbench.Initialize(flag.CommandLine)
    29  }
    30  
    31  func sendICMPError(t *testing.T, conn *testbench.TCPIPv4, tcp *testbench.TCP) {
    32  	t.Helper()
    33  
    34  	icmpPayload := testbench.Layers{tcp.Prev(), tcp}
    35  	bytes, err := icmpPayload.ToBytes()
    36  	if err != nil {
    37  		t.Fatalf("got icmpPayload.ToBytes() = (_, %s), want = (_, nil)", err)
    38  	}
    39  
    40  	layers := conn.CreateFrame(t, nil)
    41  	layers[len(layers)-1] = &testbench.ICMPv4{
    42  		Type:    testbench.ICMPv4Type(header.ICMPv4DstUnreachable),
    43  		Code:    testbench.ICMPv4Code(header.ICMPv4HostUnreachable),
    44  		Payload: bytes,
    45  	}
    46  	conn.SendFrameStateless(t, layers)
    47  }
    48  
    49  // TestTCPConnectICMPError tests for the handshake to fail and the socket state
    50  // cleaned up on receiving an ICMP error.
    51  func TestTCPConnectICMPError(t *testing.T) {
    52  	dut := testbench.NewDUT(t)
    53  
    54  	clientFD, clientPort := dut.CreateBoundSocket(t, unix.SOCK_STREAM|unix.SOCK_NONBLOCK, unix.IPPROTO_TCP, dut.Net.RemoteIPv4)
    55  	port := uint16(9001)
    56  	conn := dut.Net.NewTCPIPv4(t, testbench.TCP{SrcPort: &port, DstPort: &clientPort}, testbench.TCP{SrcPort: &clientPort, DstPort: &port})
    57  	defer conn.Close(t)
    58  	sa := unix.SockaddrInet4{Port: int(port)}
    59  	copy(sa.Addr[:], dut.Net.LocalIPv4)
    60  	// Bring the dut to SYN-SENT state with a non-blocking connect.
    61  	dut.Connect(t, clientFD, &sa)
    62  	tcp, err := conn.Expect(t, testbench.TCP{Flags: testbench.TCPFlags(header.TCPFlagSyn)}, time.Second)
    63  	if err != nil {
    64  		t.Fatalf("expected SYN, %s", err)
    65  	}
    66  
    67  	// Continuously try to read the ICMP error in an attempt to trigger a race
    68  	// condition.
    69  	start := make(chan struct{})
    70  	done := make(chan struct{})
    71  	go func() {
    72  		defer close(done)
    73  
    74  		close(start)
    75  		for {
    76  			select {
    77  			case <-done:
    78  				return
    79  			default:
    80  			}
    81  			const want = unix.EHOSTUNREACH
    82  			switch got := unix.Errno(dut.GetSockOptInt(t, clientFD, unix.SOL_SOCKET, unix.SO_ERROR)); got {
    83  			case unix.Errno(0):
    84  				continue
    85  			case want:
    86  				return
    87  			default:
    88  				t.Fatalf("got SO_ERROR = %s, want %s", got, want)
    89  			}
    90  
    91  		}
    92  	}()
    93  
    94  	<-start
    95  	sendICMPError(t, &conn, tcp)
    96  
    97  	dut.PollOne(t, clientFD, unix.POLLHUP, time.Second)
    98  	<-done
    99  
   100  	conn.Send(t, testbench.TCP{Flags: testbench.TCPFlags(header.TCPFlagAck)})
   101  	// The DUT should reply with RST to our ACK as the state should have
   102  	// transitioned to CLOSED because of handshake error.
   103  	if _, err := conn.Expect(t, testbench.TCP{Flags: testbench.TCPFlags(header.TCPFlagRst)}, time.Second); err != nil {
   104  		t.Fatalf("expected RST, %s", err)
   105  	}
   106  }