1 files changed, 151 insertions, 0 deletions
diff --git a/projects/leveldb/fuzz_db.cc b/projects/leveldb/fuzz_db.cc
new file mode 100644
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+++ b/projects/leveldb/fuzz_db.cc
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+/* Copyright 2020 Google Inc.
+
+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 <cstdint>
+#include <cstddef>
+#include <filesystem>
+#include <memory>
+#include <string>
+
+#include "leveldb/db.h"
+#include "leveldb/iterator.h"
+#include "leveldb/options.h"
+#include "leveldb/status.h"
+
+#include <fuzzer/FuzzedDataProvider.h>
+
+namespace {
+
+// Deletes the database directory when going out of scope.
+class AutoDbDeleter {
+ public:
+  static constexpr char kDbPath[] = "/tmp/testdb";
+
+  AutoDbDeleter() = default;
+
+  AutoDbDeleter(const AutoDbDeleter&) = delete;
+  AutoDbDeleter& operator=(const AutoDbDeleter&) = delete;
+
+  ~AutoDbDeleter() {
+    std::__fs::filesystem::remove_all(kDbPath);
+  }
+};
+
+// static
+constexpr char AutoDbDeleter::kDbPath[];
+
+// Returns nullptr (a falsey unique_ptr) if opening fails.
+std::unique_ptr<leveldb::DB> OpenDB() {
+  leveldb::Options options;
+  options.create_if_missing = true;
+
+  leveldb::DB* db_ptr;
+  leveldb::Status status =
+      leveldb::DB::Open(options, AutoDbDeleter::kDbPath, &db_ptr);
+  if (!status.ok())
+    return nullptr;
+
+  return std::unique_ptr<leveldb::DB>(db_ptr);
+}
+
+enum class FuzzOp {
+  kPut = 0,
+  kGet = 1,
+  kDelete = 2,
+  kGetProperty = 3,
+  kIterate = 4,
+  kGetReleaseSnapshot = 5,
+  kReopenDb = 6,
+  kCompactRange = 7,
+  // Add new values here.
+
+  // When adding new values, update to the last value above.
+  kMaxValue = kCompactRange,
+};
+
+}  // namespace
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+  // Must occur before `db` so the deletion doesn't happen while the DB is open.
+  AutoDbDeleter db_deleter;
+
+  std::unique_ptr<leveldb::DB> db = OpenDB();
+  if (!db.get())
+    return 0;
+
+  // Perform a sequence of operations on the database.
+  FuzzedDataProvider fuzzed_data(data, size);
+  while (fuzzed_data.remaining_bytes() != 0) {
+    FuzzOp fuzz_op = fuzzed_data.ConsumeEnum<FuzzOp>();
+
+    switch (fuzz_op) {
+    case FuzzOp::kPut: {
+      std::string key = fuzzed_data.ConsumeRandomLengthString();
+      std::string value = fuzzed_data.ConsumeRandomLengthString();
+      db->Put(leveldb::WriteOptions(), key, value);
+      break;
+    }
+    case FuzzOp::kGet: {
+      std::string key = fuzzed_data.ConsumeRandomLengthString();
+      std::string value;
+      db->Get(leveldb::ReadOptions(), key, &value);
+      break;
+    }
+    case FuzzOp::kDelete: {
+      std::string key = fuzzed_data.ConsumeRandomLengthString();
+      db->Delete(leveldb::WriteOptions(), key);
+      break;
+    }
+    case FuzzOp::kGetProperty: {
+      std::string name = fuzzed_data.ConsumeRandomLengthString();
+      std::string value;
+      db->GetProperty(name, &value);
+      break;
+    }
+    case FuzzOp::kIterate: {
+      std::unique_ptr<leveldb::Iterator> it(
+          db->NewIterator(leveldb::ReadOptions()));
+      for (it->SeekToFirst(); it->Valid(); it->Next())
+        continue;
+    }
+    case FuzzOp::kGetReleaseSnapshot: {
+      leveldb::ReadOptions snapshot_options;
+      snapshot_options.snapshot = db->GetSnapshot();
+      std::unique_ptr<leveldb::Iterator> it(db->NewIterator(snapshot_options));
+      db->ReleaseSnapshot(snapshot_options.snapshot);
+    }
+    case FuzzOp::kReopenDb: {
+      // The database must be closed before attempting to reopen it. Otherwise,
+      // the open will fail due to exclusive locking.
+      db.reset();
+      db = OpenDB();
+      if (!db)
+        return 0;  // Reopening the database failed.
+      break;
+    }
+    case FuzzOp::kCompactRange: {
+      std::string begin_key = fuzzed_data.ConsumeRandomLengthString();
+      std::string end_key =  fuzzed_data.ConsumeRandomLengthString();
+      leveldb::Slice begin_slice(begin_key);
+      leveldb::Slice end_slice(end_key);
+      db->CompactRange(&begin_slice, &end_slice);
+      break;
+    }
+    }
+  }
+
+  return 0;
+}