pkg/sensors: add a regression test on long args

This test make sure that we don't have a regression on the bug fixed in the previous commit about truncating long args. Signed-off-by: Mahe Tardy <[email protected]>
cilium · Feb 21, 2025 · f655438 · f655438
1 parent c82d287
commit f655438
Showing 1 changed file with 59 additions and 0 deletions.
diff --git a/pkg/sensors/tracing/kprobe_test.go b/pkg/sensors/tracing/kprobe_test.go
@@ -13,7 +13,9 @@ import (
 	"os"
 	"os/exec"
 	"os/signal"
+	"path"
 	"path/filepath"
+	"slices"
 	"strconv"
 	"strings"
 	"sync"
@@ -7211,3 +7213,60 @@ spec:
 	err = jsonchecker.JsonTestCheck(t, checker)
 	assert.NoError(t, err)
 }
+
+func TestKprobeMatchArgsLongFile(t *testing.T) {
+	var doneWG, readyWG sync.WaitGroup
+	defer doneWG.Wait()
+
+	ctx, cancel := context.WithTimeout(context.Background(), tus.Conf().CmdWaitTime)
+	defer cancel()
+
+	// depending on temp dir, this should generate a path of ~2000 chars
+	longDirectory := strings.Repeat("a", 255)
+	longPathSlices := slices.Repeat([]string{longDirectory}, 8)
+	longPath := path.Join(t.TempDir(), path.Join(longPathSlices...))
+
+	// create a long temporary directory structure
+	err := os.MkdirAll(longPath, 0644)
+	require.NoError(t, err)
+	longPathWithFile := path.Join(longPath, "file")
+	file, err := os.Create(longPathWithFile)
+	require.NoError(t, err)
+	file.Close()
+
+	fdinstallHook := `apiVersion: cilium.io/v1alpha1
+kind: TracingPolicy
+metadata:
+  name: "fdinstall"
+spec:
+  kprobes:
+  - call: "fd_install"
+    syscall: false
+    args:
+    - index: 1
+      type: "file"`
+
+	createCrdFile(t, fdinstallHook)
+
+	longFileArgChecker := ec.NewProcessKprobeChecker("longFile").
+		WithFunctionName(sm.Full("fd_install")).
+		WithArgs(ec.NewKprobeArgumentListMatcher().WithValues(
+			ec.NewKprobeArgumentChecker().WithFileArg(ec.NewKprobeFileChecker().WithPath(sm.Full(longPathWithFile))),
+		))
+
+	obs, err := observertesthelper.GetDefaultObserverWithFile(t, ctx, testConfigFile, tus.Conf().TetragonLib, observertesthelper.WithMyPid())
+	if err != nil {
+		t.Fatalf("GetDefaultObserverWithFile error: %s", err)
+	}
+	observertesthelper.LoopEvents(ctx, t, &doneWG, &readyWG, obs)
+	readyWG.Wait()
+
+	// generate an event by opening the file
+	file, err = os.Open(longPathWithFile)
+	require.NoError(t, err)
+	file.Close()
+
+	checker := ec.NewUnorderedEventChecker(longFileArgChecker)
+	err = jsonchecker.JsonTestCheck(t, checker)
+	assert.NoError(t, err)
+}