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-rw-r--r--pkg/tcpip/network/ipv4/BUILD1
-rw-r--r--pkg/tcpip/network/ipv4/ipv4_test.go250
2 files changed, 251 insertions, 0 deletions
diff --git a/pkg/tcpip/network/ipv4/BUILD b/pkg/tcpip/network/ipv4/BUILD
index 880ea7de2..78420d6e6 100644
--- a/pkg/tcpip/network/ipv4/BUILD
+++ b/pkg/tcpip/network/ipv4/BUILD
@@ -34,5 +34,6 @@ go_test(
"//pkg/tcpip/transport/tcp",
"//pkg/tcpip/transport/udp",
"//pkg/waiter",
+ "@com_github_google_go-cmp//cmp:go_default_library",
],
)
diff --git a/pkg/tcpip/network/ipv4/ipv4_test.go b/pkg/tcpip/network/ipv4/ipv4_test.go
index 5a864d832..36035c820 100644
--- a/pkg/tcpip/network/ipv4/ipv4_test.go
+++ b/pkg/tcpip/network/ipv4/ipv4_test.go
@@ -20,6 +20,7 @@ import (
"math/rand"
"testing"
+ "github.com/google/go-cmp/cmp"
"gvisor.dev/gvisor/pkg/tcpip"
"gvisor.dev/gvisor/pkg/tcpip/buffer"
"gvisor.dev/gvisor/pkg/tcpip/header"
@@ -473,3 +474,252 @@ func TestInvalidFragments(t *testing.T) {
})
}
}
+
+// TestReceiveFragments feeds fragments in through the incoming packet path to
+// test reassembly
+func TestReceiveFragments(t *testing.T) {
+ const addr1 = "\x0c\xa8\x00\x01" // 192.168.0.1
+ const addr2 = "\x0c\xa8\x00\x02" // 192.168.0.2
+ const nicID = 1
+
+ // Build and return a UDP header containing payload.
+ udpGen := func(payloadLen int, multiplier uint8) buffer.View {
+ payload := buffer.NewView(payloadLen)
+ for i := 0; i < len(payload); i++ {
+ payload[i] = uint8(i) * multiplier
+ }
+
+ udpLength := header.UDPMinimumSize + len(payload)
+
+ hdr := buffer.NewPrependable(udpLength)
+ u := header.UDP(hdr.Prepend(udpLength))
+ u.Encode(&header.UDPFields{
+ SrcPort: 5555,
+ DstPort: 80,
+ Length: uint16(udpLength),
+ })
+ copy(u.Payload(), payload)
+ sum := header.PseudoHeaderChecksum(udp.ProtocolNumber, addr1, addr2, uint16(udpLength))
+ sum = header.Checksum(payload, sum)
+ u.SetChecksum(^u.CalculateChecksum(sum))
+ return hdr.View()
+ }
+
+ // UDP header plus a payload of 0..256
+ ipv4Payload1 := udpGen(256, 1)
+ udpPayload1 := ipv4Payload1[header.UDPMinimumSize:]
+ // UDP header plus a payload of 0..256 in increments of 2.
+ ipv4Payload2 := udpGen(128, 2)
+ udpPayload2 := ipv4Payload2[header.UDPMinimumSize:]
+
+ type fragmentData struct {
+ id uint16
+ flags uint8
+ fragmentOffset uint16
+ payload buffer.View
+ }
+
+ tests := []struct {
+ name string
+ fragments []fragmentData
+ expectedPayloads [][]byte
+ }{
+ {
+ name: "No fragmentation",
+ fragments: []fragmentData{
+ {
+ id: 1,
+ flags: 0,
+ fragmentOffset: 0,
+ payload: ipv4Payload1,
+ },
+ },
+ expectedPayloads: [][]byte{udpPayload1},
+ },
+ {
+ name: "More fragments without payload",
+ fragments: []fragmentData{
+ {
+ id: 1,
+ flags: header.IPv4FlagMoreFragments,
+ fragmentOffset: 0,
+ payload: ipv4Payload1,
+ },
+ },
+ expectedPayloads: nil,
+ },
+ {
+ name: "Non-zero fragment offset without payload",
+ fragments: []fragmentData{
+ {
+ id: 1,
+ flags: 0,
+ fragmentOffset: 8,
+ payload: ipv4Payload1,
+ },
+ },
+ expectedPayloads: nil,
+ },
+ {
+ name: "Two fragments",
+ fragments: []fragmentData{
+ {
+ id: 1,
+ flags: header.IPv4FlagMoreFragments,
+ fragmentOffset: 0,
+ payload: ipv4Payload1[:64],
+ },
+ {
+ id: 1,
+ flags: 0,
+ fragmentOffset: 64,
+ payload: ipv4Payload1[64:],
+ },
+ },
+ expectedPayloads: [][]byte{udpPayload1},
+ },
+ {
+ name: "Second fragment has MoreFlags set",
+ fragments: []fragmentData{
+ {
+ id: 1,
+ flags: header.IPv4FlagMoreFragments,
+ fragmentOffset: 0,
+ payload: ipv4Payload1[:64],
+ },
+ {
+ id: 1,
+ flags: header.IPv4FlagMoreFragments,
+ fragmentOffset: 64,
+ payload: ipv4Payload1[64:],
+ },
+ },
+ expectedPayloads: nil,
+ },
+ {
+ name: "Two fragments with different IDs",
+ fragments: []fragmentData{
+ {
+ id: 1,
+ flags: header.IPv4FlagMoreFragments,
+ fragmentOffset: 0,
+ payload: ipv4Payload1[:64],
+ },
+ {
+ id: 2,
+ flags: 0,
+ fragmentOffset: 64,
+ payload: ipv4Payload1[64:],
+ },
+ },
+ expectedPayloads: nil,
+ },
+ {
+ name: "Two interleaved fragmented packets",
+ fragments: []fragmentData{
+ {
+ id: 1,
+ flags: header.IPv4FlagMoreFragments,
+ fragmentOffset: 0,
+ payload: ipv4Payload1[:64],
+ },
+ {
+ id: 2,
+ flags: header.IPv4FlagMoreFragments,
+ fragmentOffset: 0,
+ payload: ipv4Payload2[:64],
+ },
+ {
+ id: 1,
+ flags: 0,
+ fragmentOffset: 64,
+ payload: ipv4Payload1[64:],
+ },
+ {
+ id: 2,
+ flags: 0,
+ fragmentOffset: 64,
+ payload: ipv4Payload2[64:],
+ },
+ },
+ expectedPayloads: [][]byte{udpPayload1, udpPayload2},
+ },
+ }
+
+ for _, test := range tests {
+ t.Run(test.name, func(t *testing.T) {
+ // Setup a stack and endpoint.
+ s := stack.New(stack.Options{
+ NetworkProtocols: []stack.NetworkProtocol{ipv4.NewProtocol()},
+ TransportProtocols: []stack.TransportProtocol{udp.NewProtocol()},
+ })
+ e := channel.New(0, 1280, tcpip.LinkAddress("\xf0\x00"))
+ if err := s.CreateNIC(nicID, e); err != nil {
+ t.Fatalf("CreateNIC(%d, _) = %s", nicID, err)
+ }
+ if err := s.AddAddress(nicID, header.IPv4ProtocolNumber, addr2); err != nil {
+ t.Fatalf("AddAddress(%d, %d, %s) = %s", nicID, header.IPv4ProtocolNumber, addr2, err)
+ }
+
+ wq := waiter.Queue{}
+ we, ch := waiter.NewChannelEntry(nil)
+ wq.EventRegister(&we, waiter.EventIn)
+ defer wq.EventUnregister(&we)
+ defer close(ch)
+ ep, err := s.NewEndpoint(udp.ProtocolNumber, header.IPv4ProtocolNumber, &wq)
+ if err != nil {
+ t.Fatalf("NewEndpoint(%d, %d, _): %s", udp.ProtocolNumber, header.IPv4ProtocolNumber, err)
+ }
+ defer ep.Close()
+
+ bindAddr := tcpip.FullAddress{Addr: addr2, Port: 80}
+ if err := ep.Bind(bindAddr); err != nil {
+ t.Fatalf("Bind(%+v): %s", bindAddr, err)
+ }
+
+ // Prepare and send the fragments.
+ for _, frag := range test.fragments {
+ hdr := buffer.NewPrependable(header.IPv4MinimumSize)
+
+ // Serialize IPv4 fixed header.
+ ip := header.IPv4(hdr.Prepend(header.IPv4MinimumSize))
+ ip.Encode(&header.IPv4Fields{
+ IHL: header.IPv4MinimumSize,
+ TotalLength: header.IPv4MinimumSize + uint16(len(frag.payload)),
+ ID: frag.id,
+ Flags: frag.flags,
+ FragmentOffset: frag.fragmentOffset,
+ TTL: 64,
+ Protocol: uint8(header.UDPProtocolNumber),
+ SrcAddr: addr1,
+ DstAddr: addr2,
+ })
+
+ vv := hdr.View().ToVectorisedView()
+ vv.AppendView(frag.payload)
+
+ e.InjectInbound(header.IPv4ProtocolNumber, stack.PacketBuffer{
+ Data: vv,
+ })
+ }
+
+ if got, want := s.Stats().UDP.PacketsReceived.Value(), uint64(len(test.expectedPayloads)); got != want {
+ t.Errorf("got UDP Rx Packets = %d, want = %d", got, want)
+ }
+
+ for i, expectedPayload := range test.expectedPayloads {
+ gotPayload, _, err := ep.Read(nil)
+ if err != nil {
+ t.Fatalf("(i=%d) Read(nil): %s", i, err)
+ }
+ if diff := cmp.Diff(buffer.View(expectedPayload), gotPayload); diff != "" {
+ t.Errorf("(i=%d) got UDP payload mismatch (-want +got):\n%s", i, diff)
+ }
+ }
+
+ if gotPayload, _, err := ep.Read(nil); err != tcpip.ErrWouldBlock {
+ t.Fatalf("(last) got Read(nil) = (%x, _, %v), want = (_, _, %s)", gotPayload, err, tcpip.ErrWouldBlock)
+ }
+ })
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-02 10:22:30 +0000