add a test for tricking the server into allocating huge buffers

2 files changed, 64 insertions, 0 deletions

diff --git a/nslcd_systemd/misc_test.go b/nslcd_systemd/misc_test.go
index 8ef697a..0e6f2e9 100644
--- a/nslcd_systemd/misc_test.go
+++ b/nslcd_systemd/misc_test.go
@@ -283,3 +283,48 @@ func TestClientHang(t *testing.T) {
 		}()
 	}
 }
+
+func TestLargeRequest(t *testing.T) {
+	tmpdir, err := ioutil.TempDir("", "go-test-libnslcd-large-request.")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpdir)
+	defer sdActivatedReset()
+	t.Run("large-request", func(t *testing.T) {
+		testWithTimeout(t, 2*time.Second, func(t *testing.T, s chan<- string) {
+			GiB := 1024*1024*1024
+			ctx := &testContext{T: t, tmpdir: tmpdir, status: s}
+
+			backend := &LockingBackend{}
+
+			limits := nslcd_server.Limits{
+				Timeout: 1 * time.Second,
+			}
+
+			notifyHandler := func(dat []byte, oob []byte) error { return nil }
+
+			client := func(sockname string) {
+				errfatal := func(err error) {
+					if err != nil {
+						t.Fatal(err)
+					}
+				}
+
+				conn, err := net.Dial("unix", sockname)
+				errfatal(err)
+				errfatal(nslcd_proto.Write(conn, nslcd_proto.NSLCD_VERSION))
+				errfatal(nslcd_proto.Write(conn, nslcd_proto.NSLCD_ACTION_PASSWD_BYNAME))
+				errfatal(nslcd_proto.Write(conn, int32(1*GiB)))
+			}
+
+			testDriver(ctx, backend, limits, notifyHandler, client)
+
+			var memstats runtime.MemStats
+			runtime.ReadMemStats(&memstats)
+			if memstats.HeapSys > uint64(1*GiB) {
+				t.Fatalf("Used more than 1 GiB heap: %s B", humanizeU64(memstats.HeapSys))
+			}
+		})
+	})
+}
diff --git a/nslcd_systemd/util_test.go b/nslcd_systemd/util_test.go
index 15147b7..89cf7cb 100644
--- a/nslcd_systemd/util_test.go
+++ b/nslcd_systemd/util_test.go
@@ -191,3 +191,22 @@ func sdNotifyHandle(sock *net.UnixConn, fn func(dat []byte, oob []byte) error) e
 		}
 	}
 }
+
+func humanizeU64(n uint64) string {
+	str := fmt.Sprintf("%d", n)
+	bts := make([]byte, len(str)+(len(str)-1)/3)
+
+	s := 0
+	b := 0
+	for s < len(str) && b < len(bts) {
+		if (s % 3 == 0 && s > 0) {
+			bts[len(bts)-1-b] = ','
+			b++
+		}
+		bts[len(bts)-1-b] = str[len(str)-1-s]
+		b++
+		s++
+	}
+
+	return string(bts)
+}