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-rw-r--r--test/packetimpact/testbench/connections.go94
-rw-r--r--test/packetimpact/testbench/layers.go245
-rw-r--r--test/packetimpact/testbench/layers_test.go80
-rw-r--r--test/packetimpact/tests/fin_wait2_timeout_test.go4
4 files changed, 376 insertions, 47 deletions
diff --git a/test/packetimpact/testbench/connections.go b/test/packetimpact/testbench/connections.go
index 952a717e0..42a90a859 100644
--- a/test/packetimpact/testbench/connections.go
+++ b/test/packetimpact/testbench/connections.go
@@ -21,7 +21,6 @@ import (
"fmt"
"math/rand"
"net"
- "strings"
"testing"
"time"
@@ -66,14 +65,16 @@ func pickPort() (int, uint16, error) {
// layerState stores the state of a layer of a connection.
type layerState interface {
- // outgoing returns an outgoing layer to be sent in a frame.
+ // 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. The
- // calles takes ownership of the returned Layer.
+ // 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
@@ -363,44 +364,33 @@ type Connection struct {
t *testing.T
}
-// match tries to match each Layer in received against the incoming filter. If
-// received is longer than layerStates then that may still count as a match. The
-// reverse is never a match. override overrides the default matchers for each
-// Layer.
-func (conn *Connection) match(override, received Layers) bool {
- var layersToMatch int
- if len(override) < len(conn.layerStates) {
- layersToMatch = len(conn.layerStates)
- } else {
- layersToMatch = len(override)
- }
- if len(received) < layersToMatch {
- return false
- }
- for i := 0; i < layersToMatch; i++ {
- var toMatch Layer
- if i < len(conn.layerStates) {
- s := conn.layerStates[i]
- toMatch = s.incoming(received[i])
- if toMatch == nil {
- return false
- }
- if i < len(override) {
- if err := toMatch.merge(override[i]); err != nil {
- conn.t.Fatalf("failed to merge: %s", err)
- }
- }
- } else {
- toMatch = override[i]
- if toMatch == nil {
- conn.t.Fatalf("expect the overriding layers to be non-nil")
- }
- }
- if !toMatch.match(received[i]) {
- return false
+// 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.
}
- return true
+ 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.
@@ -470,6 +460,16 @@ func (conn *Connection) recvFrame(timeout time.Duration) Layers {
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 a frame with the final layerStates layer matching the provided Layer
// within the timeout specified. If it doesn't arrive in time, it returns nil.
func (conn *Connection) Expect(layer Layer, timeout time.Duration) (Layer, error) {
@@ -485,21 +485,25 @@ func (conn *Connection) Expect(layer Layer, timeout time.Duration) (Layer, error
return gotFrame[len(conn.layerStates)-1], nil
}
conn.t.Fatal("the received frame should be at least as long as the expected layers")
- return nil, fmt.Errorf("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 it doesn't arrive in time, it returns nil.
+// 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 allLayers []string
+ var errs error
for {
var gotLayers Layers
if timeout = time.Until(deadline); timeout > 0 {
gotLayers = conn.recvFrame(timeout)
}
if gotLayers == nil {
- return nil, fmt.Errorf("got %d packets:\n%s", len(allLayers), strings.Join(allLayers, "\n"))
+ 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 {
@@ -509,7 +513,7 @@ func (conn *Connection) ExpectFrame(layers Layers, timeout time.Duration) (Layer
}
return gotLayers, nil
}
- allLayers = append(allLayers, fmt.Sprintf("%s", gotLayers))
+ errs = multierr.Combine(errs, &layersError{got: gotLayers, want: conn.incoming(gotLayers)})
}
}
diff --git a/test/packetimpact/testbench/layers.go b/test/packetimpact/testbench/layers.go
index 01e99567d..2cbbbb318 100644
--- a/test/packetimpact/testbench/layers.go
+++ b/test/packetimpact/testbench/layers.go
@@ -22,6 +22,7 @@ import (
"github.com/google/go-cmp/cmp"
"github.com/google/go-cmp/cmp/cmpopts"
+ "go.uber.org/multierr"
"gvisor.dev/gvisor/pkg/tcpip"
"gvisor.dev/gvisor/pkg/tcpip/buffer"
"gvisor.dev/gvisor/pkg/tcpip/header"
@@ -720,3 +721,247 @@ func (ls *Layers) match(other Layers) bool {
}
return true
}
+
+// layerDiff stores the diffs for each field along with the label for the Layer.
+// If rows is nil, that means that there was no diff.
+type layerDiff struct {
+ label string
+ rows []layerDiffRow
+}
+
+// layerDiffRow stores the fields and corresponding values for two got and want
+// layers. If the value was nil then the string stored is the empty string.
+type layerDiffRow struct {
+ field, got, want string
+}
+
+// diffLayer extracts all differing fields between two layers.
+func diffLayer(got, want Layer) []layerDiffRow {
+ vGot := reflect.ValueOf(got).Elem()
+ vWant := reflect.ValueOf(want).Elem()
+ if vGot.Type() != vWant.Type() {
+ return nil
+ }
+ t := vGot.Type()
+ var result []layerDiffRow
+ for i := 0; i < t.NumField(); i++ {
+ t := t.Field(i)
+ if t.Anonymous {
+ // Ignore the LayerBase in the Layer struct.
+ continue
+ }
+ vGot := vGot.Field(i)
+ vWant := vWant.Field(i)
+ gotString := ""
+ if !vGot.IsNil() {
+ gotString = fmt.Sprint(reflect.Indirect(vGot))
+ }
+ wantString := ""
+ if !vWant.IsNil() {
+ wantString = fmt.Sprint(reflect.Indirect(vWant))
+ }
+ result = append(result, layerDiffRow{t.Name, gotString, wantString})
+ }
+ return result
+}
+
+// layerType returns a concise string describing the type of the Layer, like
+// "TCP", or "IPv6".
+func layerType(l Layer) string {
+ return reflect.TypeOf(l).Elem().Name()
+}
+
+// diff compares Layers and returns a representation of the difference. Each
+// Layer in the Layers is pairwise compared. If an element in either is nil, it
+// is considered a match with the other Layer. If two Layers have differing
+// types, they don't match regardless of the contents. If two Layers have the
+// same type then the fields in the Layer are pairwise compared. Fields that are
+// nil always match. Two non-nil fields only match if they point to equal
+// values. diff returns an empty string if and only if *ls and other match.
+func (ls *Layers) diff(other Layers) string {
+ var allDiffs []layerDiff
+ // Check the cases where one list is longer than the other, where one or both
+ // elements are nil, where the sides have different types, and where the sides
+ // have the same type.
+ for i := 0; i < len(*ls) || i < len(other); i++ {
+ if i >= len(*ls) {
+ // Matching ls against other where other is longer than ls. missing
+ // matches everything so we just include a label without any rows. Having
+ // no rows is a sign that there was no diff.
+ allDiffs = append(allDiffs, layerDiff{
+ label: "missing matches " + layerType(other[i]),
+ })
+ continue
+ }
+
+ if i >= len(other) {
+ // Matching ls against other where ls is longer than other. missing
+ // matches everything so we just include a label without any rows. Having
+ // no rows is a sign that there was no diff.
+ allDiffs = append(allDiffs, layerDiff{
+ label: layerType((*ls)[i]) + " matches missing",
+ })
+ continue
+ }
+
+ if (*ls)[i] == nil && other[i] == nil {
+ // Matching ls against other where both elements are nil. nil matches
+ // everything so we just include a label without any rows. Having no rows
+ // is a sign that there was no diff.
+ allDiffs = append(allDiffs, layerDiff{
+ label: "nil matches nil",
+ })
+ continue
+ }
+
+ if (*ls)[i] == nil {
+ // Matching ls against other where the element in ls is nil. nil matches
+ // everything so we just include a label without any rows. Having no rows
+ // is a sign that there was no diff.
+ allDiffs = append(allDiffs, layerDiff{
+ label: "nil matches " + layerType(other[i]),
+ })
+ continue
+ }
+
+ if other[i] == nil {
+ // Matching ls against other where the element in other is nil. nil
+ // matches everything so we just include a label without any rows. Having
+ // no rows is a sign that there was no diff.
+ allDiffs = append(allDiffs, layerDiff{
+ label: layerType((*ls)[i]) + " matches nil",
+ })
+ continue
+ }
+
+ if reflect.TypeOf((*ls)[i]) == reflect.TypeOf(other[i]) {
+ // Matching ls against other where both elements have the same type. Match
+ // each field pairwise and only report a diff if there is a mismatch,
+ // which is only when both sides are non-nil and have differring values.
+ diff := diffLayer((*ls)[i], other[i])
+ var layerDiffRows []layerDiffRow
+ for _, d := range diff {
+ if d.got == "" || d.want == "" || d.got == d.want {
+ continue
+ }
+ layerDiffRows = append(layerDiffRows, layerDiffRow{
+ d.field,
+ d.got,
+ d.want,
+ })
+ }
+ if len(layerDiffRows) > 0 {
+ allDiffs = append(allDiffs, layerDiff{
+ label: layerType((*ls)[i]),
+ rows: layerDiffRows,
+ })
+ } else {
+ allDiffs = append(allDiffs, layerDiff{
+ label: layerType((*ls)[i]) + " matches " + layerType(other[i]),
+ // Having no rows is a sign that there was no diff.
+ })
+ }
+ continue
+ }
+ // Neither side is nil and the types are different, so we'll display one
+ // side then the other.
+ allDiffs = append(allDiffs, layerDiff{
+ label: layerType((*ls)[i]) + " doesn't match " + layerType(other[i]),
+ })
+ diff := diffLayer((*ls)[i], (*ls)[i])
+ layerDiffRows := []layerDiffRow{}
+ for _, d := range diff {
+ if len(d.got) == 0 {
+ continue
+ }
+ layerDiffRows = append(layerDiffRows, layerDiffRow{
+ d.field,
+ d.got,
+ "",
+ })
+ }
+ allDiffs = append(allDiffs, layerDiff{
+ label: layerType((*ls)[i]),
+ rows: layerDiffRows,
+ })
+
+ layerDiffRows = []layerDiffRow{}
+ diff = diffLayer(other[i], other[i])
+ for _, d := range diff {
+ if len(d.want) == 0 {
+ continue
+ }
+ layerDiffRows = append(layerDiffRows, layerDiffRow{
+ d.field,
+ "",
+ d.want,
+ })
+ }
+ allDiffs = append(allDiffs, layerDiff{
+ label: layerType(other[i]),
+ rows: layerDiffRows,
+ })
+ }
+
+ output := ""
+ // These are for output formatting.
+ maxLabelLen, maxFieldLen, maxGotLen, maxWantLen := 0, 0, 0, 0
+ foundOne := false
+ for _, l := range allDiffs {
+ if len(l.label) > maxLabelLen && len(l.rows) > 0 {
+ maxLabelLen = len(l.label)
+ }
+ if l.rows != nil {
+ foundOne = true
+ }
+ for _, r := range l.rows {
+ if len(r.field) > maxFieldLen {
+ maxFieldLen = len(r.field)
+ }
+ if l := len(fmt.Sprint(r.got)); l > maxGotLen {
+ maxGotLen = l
+ }
+ if l := len(fmt.Sprint(r.want)); l > maxWantLen {
+ maxWantLen = l
+ }
+ }
+ }
+ if !foundOne {
+ return ""
+ }
+ for _, l := range allDiffs {
+ if len(l.rows) == 0 {
+ output += "(" + l.label + ")\n"
+ continue
+ }
+ for i, r := range l.rows {
+ var label string
+ if i == 0 {
+ label = l.label + ":"
+ }
+ output += fmt.Sprintf(
+ "%*s %*s %*v %*v\n",
+ maxLabelLen+1, label,
+ maxFieldLen+1, r.field+":",
+ maxGotLen, r.got,
+ maxWantLen, r.want,
+ )
+ }
+ }
+ return output
+}
+
+// merge merges the other Layers into ls. If the other Layers is longer, those
+// additional Layer structs are added to ls. The errors from merging are
+// collected and returned.
+func (ls *Layers) merge(other Layers) error {
+ var errs error
+ for i, o := range other {
+ if i < len(*ls) {
+ errs = multierr.Combine(errs, (*ls)[i].merge(o))
+ } else {
+ *ls = append(*ls, o)
+ }
+ }
+ return errs
+}
diff --git a/test/packetimpact/testbench/layers_test.go b/test/packetimpact/testbench/layers_test.go
index f07ec5eb2..96f72de5b 100644
--- a/test/packetimpact/testbench/layers_test.go
+++ b/test/packetimpact/testbench/layers_test.go
@@ -313,3 +313,83 @@ func TestConnectionMatch(t *testing.T) {
})
}
}
+
+func TestLayersDiff(t *testing.T) {
+ for _, tt := range []struct {
+ x, y Layers
+ want string
+ }{
+ {
+ Layers{&Ether{Type: NetworkProtocolNumber(12)}, &TCP{DataOffset: Uint8(5), SeqNum: Uint32(5)}},
+ Layers{&Ether{Type: NetworkProtocolNumber(13)}, &TCP{DataOffset: Uint8(7), SeqNum: Uint32(6)}},
+ "Ether: Type: 12 13\n" +
+ " TCP: SeqNum: 5 6\n" +
+ " DataOffset: 5 7\n",
+ },
+ {
+ Layers{&Ether{Type: NetworkProtocolNumber(12)}, &UDP{SrcPort: Uint16(123)}},
+ Layers{&Ether{Type: NetworkProtocolNumber(13)}, &TCP{DataOffset: Uint8(7), SeqNum: Uint32(6)}},
+ "Ether: Type: 12 13\n" +
+ "(UDP doesn't match TCP)\n" +
+ " UDP: SrcPort: 123 \n" +
+ " TCP: SeqNum: 6\n" +
+ " DataOffset: 7\n",
+ },
+ {
+ Layers{&UDP{SrcPort: Uint16(123)}},
+ Layers{&Ether{Type: NetworkProtocolNumber(13)}, &TCP{DataOffset: Uint8(7), SeqNum: Uint32(6)}},
+ "(UDP doesn't match Ether)\n" +
+ " UDP: SrcPort: 123 \n" +
+ "Ether: Type: 13\n" +
+ "(missing matches TCP)\n",
+ },
+ {
+ Layers{nil, &UDP{SrcPort: Uint16(123)}},
+ Layers{&Ether{Type: NetworkProtocolNumber(13)}, &TCP{DataOffset: Uint8(7), SeqNum: Uint32(6)}},
+ "(nil matches Ether)\n" +
+ "(UDP doesn't match TCP)\n" +
+ "UDP: SrcPort: 123 \n" +
+ "TCP: SeqNum: 6\n" +
+ " DataOffset: 7\n",
+ },
+ {
+ Layers{&Ether{Type: NetworkProtocolNumber(13)}, &IPv4{IHL: Uint8(4)}, &TCP{DataOffset: Uint8(7), SeqNum: Uint32(6)}},
+ Layers{&Ether{Type: NetworkProtocolNumber(13)}, &IPv4{IHL: Uint8(6)}, &TCP{DataOffset: Uint8(7), SeqNum: Uint32(6)}},
+ "(Ether matches Ether)\n" +
+ "IPv4: IHL: 4 6\n" +
+ "(TCP matches TCP)\n",
+ },
+ {
+ Layers{&Payload{Bytes: []byte("foo")}},
+ Layers{&Payload{Bytes: []byte("bar")}},
+ "Payload: Bytes: [102 111 111] [98 97 114]\n",
+ },
+ {
+ Layers{&Payload{Bytes: []byte("")}},
+ Layers{&Payload{}},
+ "",
+ },
+ {
+ Layers{&Payload{Bytes: []byte("")}},
+ Layers{&Payload{Bytes: []byte("")}},
+ "",
+ },
+ {
+ Layers{&UDP{}},
+ Layers{&TCP{}},
+ "(UDP doesn't match TCP)\n" +
+ "(UDP)\n" +
+ "(TCP)\n",
+ },
+ } {
+ if got := tt.x.diff(tt.y); got != tt.want {
+ t.Errorf("%s.diff(%s) = %q, want %q", tt.x, tt.y, got, tt.want)
+ }
+ if tt.x.match(tt.y) != (tt.x.diff(tt.y) == "") {
+ t.Errorf("match and diff of %s and %s disagree", tt.x, tt.y)
+ }
+ if tt.y.match(tt.x) != (tt.y.diff(tt.x) == "") {
+ t.Errorf("match and diff of %s and %s disagree", tt.y, tt.x)
+ }
+ }
+}
diff --git a/test/packetimpact/tests/fin_wait2_timeout_test.go b/test/packetimpact/tests/fin_wait2_timeout_test.go
index b98594f94..99dc77f9a 100644
--- a/test/packetimpact/tests/fin_wait2_timeout_test.go
+++ b/test/packetimpact/tests/fin_wait2_timeout_test.go
@@ -61,8 +61,8 @@ func TestFinWait2Timeout(t *testing.T) {
t.Fatalf("expected a RST packet within a second but got none: %s", err)
}
} else {
- if _, err := conn.Expect(tb.TCP{Flags: tb.Uint8(header.TCPFlagRst)}, 10*time.Second); err == nil {
- t.Fatalf("expected no RST packets within ten seconds but got one: %s", err)
+ if got, err := conn.Expect(tb.TCP{Flags: tb.Uint8(header.TCPFlagRst)}, 10*time.Second); got != nil || err == nil {
+ t.Fatalf("expected no RST packets within ten seconds but got one: %s", got)
}
}
})
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 01:14:14 +0000