Merge "Fuzzer for libdm's dm-linear devices creation"

fs_mgr/libdm/Android.bp

@@ -79,3 +79,19 @@ cc_test {
     require_root: true,
     test_min_api_level: 29,
 }
+
+cc_fuzz {
+  name: "dm_table_fuzzer",
+  defaults: ["fs_mgr_defaults"],
+  srcs: [
+    "dm_linear_fuzzer.cpp",
+    "test_util.cpp",
+  ],
+  static_libs: [
+        "libdm",
+        "libbase",
+        "libext2_uuid",
+        "libfs_mgr",
+        "liblog",
+  ],
+}

fs_mgr/libdm/dm_linear_fuzzer.cpp

@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+
+#include <chrono>
+
+#include <android-base/file.h>
+#include <android-base/unique_fd.h>
+#include <libdm/dm_table.h>
+#include <libdm/loop_control.h>
+
+#include "test_util.h"
+
+using namespace android;
+using namespace android::base;
+using namespace android::dm;
+using namespace std;
+using namespace std::chrono_literals;
+
+/*
+ * This test aims at making the library crash, so these functions are not
+ * really useful.
+ * Keeping them here for future use.
+ */
+template <class T, class C>
+void ASSERT_EQ(const T& /*a*/, const C& /*b*/) {
+    // if (a != b) {}
+}
+
+template <class T>
+void ASSERT_FALSE(const T& /*a*/) {
+    // if (a) {}
+}
+
+template <class T, class C>
+void ASSERT_GE(const T& /*a*/, const C& /*b*/) {
+    // if (a < b) {}
+}
+
+template <class T, class C>
+void ASSERT_NE(const T& /*a*/, const C& /*b*/) {
+    // if (a == b) {}
+}
+
+template <class T>
+void ASSERT_TRUE(const T& /*a*/) {
+    // if (!a) {}
+}
+
+template <class T, class C>
+void EXPECT_EQ(const T& a, const C& b) {
+    ASSERT_EQ(a, b);
+}
+
+template <class T>
+void EXPECT_TRUE(const T& a) {
+    ASSERT_TRUE(a);
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+    uint64_t val[6];
+
+    if (size != sizeof(*val)) {
+        return 0;
+    }
+
+    memcpy(&val, &data[0], sizeof(*val));
+
+    unique_fd tmp1(CreateTempFile("file_1", 4096));
+    ASSERT_GE(tmp1, 0);
+    unique_fd tmp2(CreateTempFile("file_2", 4096));
+    ASSERT_GE(tmp2, 0);
+
+    LoopDevice loop_a(tmp1, 10s);
+    ASSERT_TRUE(loop_a.valid());
+    LoopDevice loop_b(tmp2, 10s);
+    ASSERT_TRUE(loop_b.valid());
+
+    // Define a 2-sector device, with each sector mapping to the first sector
+    // of one of our loop devices.
+    DmTable table;
+    ASSERT_TRUE(table.Emplace<DmTargetLinear>(val[0], val[1], loop_a.device(), val[2]));
+    ASSERT_TRUE(table.Emplace<DmTargetLinear>(val[3], val[4], loop_b.device(), val[5]));
+    ASSERT_TRUE(table.valid());
+    ASSERT_EQ(2u, table.num_sectors());
+
+    TempDevice dev("libdm-test-dm-linear", table);
+    ASSERT_TRUE(dev.valid());
+    ASSERT_FALSE(dev.path().empty());
+
+    auto& dm = DeviceMapper::Instance();
+
+    dev_t dev_number;
+    ASSERT_TRUE(dm.GetDeviceNumber(dev.name(), &dev_number));
+    ASSERT_NE(dev_number, 0);
+
+    std::string dev_string;
+    ASSERT_TRUE(dm.GetDeviceString(dev.name(), &dev_string));
+    ASSERT_FALSE(dev_string.empty());
+
+    // Test GetTableStatus.
+    vector<DeviceMapper::TargetInfo> targets;
+    ASSERT_TRUE(dm.GetTableStatus(dev.name(), &targets));
+    ASSERT_EQ(targets.size(), 2);
+    EXPECT_EQ(strcmp(targets[0].spec.target_type, "linear"), 0);
+    EXPECT_TRUE(targets[0].data.empty());
+    EXPECT_EQ(targets[0].spec.sector_start, 0);
+    EXPECT_EQ(targets[0].spec.length, 1);
+    EXPECT_EQ(strcmp(targets[1].spec.target_type, "linear"), 0);
+    EXPECT_TRUE(targets[1].data.empty());
+    EXPECT_EQ(targets[1].spec.sector_start, 1);
+    EXPECT_EQ(targets[1].spec.length, 1);
+
+    // Test GetTargetType().
+    EXPECT_EQ(DeviceMapper::GetTargetType(targets[0].spec), std::string{"linear"});
+    EXPECT_EQ(DeviceMapper::GetTargetType(targets[1].spec), std::string{"linear"});
+
+    // Normally the TestDevice destructor would delete this, but at least one
+    // test should ensure that device deletion works.
+    ASSERT_TRUE(dev.Destroy());
+
+    return 0;
+}