Add FUZZ test generator for packets and L2CAP fuzz tests

* Add fuzz test generator for packet generator to generate macros for
  fuzz tests
* Add a few fuzz tests for L2CAP packets

Bug: 142684649
Test: bluetooth_gd_fuzz_test
Change-Id: I75bf726b40caef3c7895596039d01c395d34506f

system/gd/fuzz_test.cc

@@ -18,8 +18,10 @@
 #include <stdint.h>
 
 extern void RunL2capClassicDynamicChannelAllocatorFuzzTest(const uint8_t* data, size_t size);
+extern void RunL2capPacketFuzzTest(const uint8_t* data, size_t size);
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
   RunL2capClassicDynamicChannelAllocatorFuzzTest(data, size);
+  RunL2capPacketFuzzTest(data, size);
   return 0;
 }
\ No newline at end of file

system/gd/l2cap/Android.bp

@@ -66,5 +66,6 @@ filegroup {
     name: "BluetoothL2capFuzzTestSources",
     srcs: [
         "classic/internal/dynamic_channel_allocator_fuzz_test.cc",
+        "l2cap_packet_fuzz_test.cc",
     ],
 }

system/gd/l2cap/l2cap_packet_fuzz_test.cc

+/*
+ * Copyright 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.
+ */
+
+#define PACKET_FUZZ_TESTING
+#include "l2cap/l2cap_packets.h"
+
+#include <gtest/gtest.h>
+#include <forward_list>
+#include <memory>
+
+#include "os/log.h"
+#include "packet/bit_inserter.h"
+#include "packet/raw_builder.h"
+
+using bluetooth::packet::BitInserter;
+using bluetooth::packet::RawBuilder;
+using std::vector;
+
+namespace bluetooth {
+namespace l2cap {
+
+DEFINE_ExtendedInformationStartFrameReflectionFuzzTest;
+
+DEFINE_StandardInformationFrameWithFcsReflectionFuzzTest;
+
+DEFINE_StandardSupervisoryFrameWithFcsReflectionFuzzTest;
+
+DEFINE_GroupFrameReflectionFuzzTest;
+
+DEFINE_ConfigurationRequestReflectionFuzzTest;
+
+}  // namespace l2cap
+}  // namespace bluetooth
+
+void RunL2capPacketFuzzTest(const uint8_t* data, size_t size) {
+  if (data == nullptr) return;
+  bluetooth::l2cap::RunExtendedInformationStartFrameReflectionFuzzTest(data, size);
+  bluetooth::l2cap::RunStandardInformationFrameWithFcsReflectionFuzzTest(data, size);
+  bluetooth::l2cap::RunStandardSupervisoryFrameWithFcsReflectionFuzzTest(data, size);
+  bluetooth::l2cap::RunGroupFrameReflectionFuzzTest(data, size);
+  bluetooth::l2cap::RunConfigurationRequestReflectionFuzzTest(data, size);
+}
\ No newline at end of file

system/gd/packet/parser/packet_def.cc

@@ -285,6 +285,9 @@ void PacketDef::GenBuilderDefinition(std::ostream& s) const {
 
   GenTestDefine(s);
   s << "\n";
+
+  GenFuzzTestDefine(s);
+  s << "\n";
 }
 
 void PacketDef::GenTestDefine(std::ostream& s) const {
@@ -336,6 +339,44 @@ void PacketDef::GenTestDefine(std::ostream& s) const {
   s << "\n#endif";
 }
 
+void PacketDef::GenFuzzTestDefine(std::ostream& s) const {
+  s << "#ifdef PACKET_FUZZ_TESTING\n";
+  s << "#define DEFINE_" << name_ << "ReflectionFuzzTest ";
+  s << "void Run" << name_ << "ReflectionFuzzTest(const uint8_t* data, size_t size) {";
+  s << "auto vec = std::make_shared<std::vector<uint8_t>>(data, data + size);";
+  s << name_ << "View view = " << name_ << "View::Create(";
+  auto ancestor_ptr = parent_;
+  size_t parent_parens = 0;
+  while (ancestor_ptr != nullptr) {
+    s << ancestor_ptr->name_ << "View::Create(";
+    parent_parens++;
+    ancestor_ptr = ancestor_ptr->parent_;
+  }
+  s << "vec";
+  for (size_t i = 0; i < parent_parens; i++) {
+    s << ")";
+  }
+  s << ");";
+  s << "if (!view.IsValid()) { return; }";
+  s << "auto packet = " << name_ << "Builder::Create(";
+  FieldList params = GetParamList().GetFieldsWithoutTypes({
+      BodyField::kFieldType,
+  });
+  for (int i = 0; i < params.size(); i++) {
+    params[i]->GenBuilderParameterFromView(s);
+    if (i != params.size() - 1) {
+      s << ", ";
+    }
+  }
+  s << ");";
+  s << "std::shared_ptr<std::vector<uint8_t>> packet_bytes = std::make_shared<std::vector<uint8_t>>();";
+  s << "packet_bytes->reserve(packet->size());";
+  s << "BitInserter it(*packet_bytes);";
+  s << "packet->Serialize(it);";
+  s << "}";
+  s << "\n#endif";
+}
+
 FieldList PacketDef::GetParametersToValidate() const {
   FieldList params_to_validate;
   for (const auto& field : GetParamList()) {

system/gd/packet/parser/packet_def.h

@@ -43,6 +43,8 @@ class PacketDef : public ParentDef {
 
   void GenTestDefine(std::ostream& s) const;
 
+  void GenFuzzTestDefine(std::ostream& s) const;
+
   FieldList GetParametersToValidate() const;
 
   void GenBuilderCreate(std::ostream& s) const;