1 /*
2 * Copyright 2020 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 // Authors: corbin.souffrant@leviathansecurity.com
17 // brian.balling@leviathansecurity.com
18
19 #include <fuzzer/FuzzedDataProvider.h>
20 #include <helpers.h>
21 #include <pdx/client_channel.h>
22 #include <pdx/service.h>
23 #include <pdx/service_dispatcher.h>
24 #include <stddef.h>
25 #include <stdint.h>
26 #include <sys/eventfd.h>
27 #include <thread>
28
29 using namespace android::pdx;
30
31 // Dispatch fuzzer entry point. This fuzzer creates a ServiceDispatcher
32 // and creates an endpoint that returns fuzzed messages that are passed
33 // to the ReceiveAndDispatch and DispatchLoop functions.
LLVMFuzzerTestOneInput(const uint8_t * data,size_t size)34 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
35 eventfd_t wakeup_val = 1;
36 FuzzedDataProvider fdp = FuzzedDataProvider(data, size);
37
38 // Endpoint is only used to be immediately wrapped as a unique_ptr,
39 // so it is ok to be using a raw ptr and new here without freeing.
40 FuzzEndpoint* endpoint = new FuzzEndpoint(&fdp);
41 std::unique_ptr<ServiceDispatcher> dispatcher = ServiceDispatcher::Create();
42 std::shared_ptr<Channel> channel(nullptr);
43 std::shared_ptr<Client> client(nullptr);
44 std::shared_ptr<Service> service(
45 new Service("FuzzService", std::unique_ptr<Endpoint>(endpoint)));
46
47 service->SetChannel(0, std::shared_ptr<Channel>(channel));
48 dispatcher->AddService(service);
49
50 // Dispatcher blocks, so needs to run in its own thread.
51 std::thread run_dispatcher([&]() {
52 uint8_t opt = 0;
53
54 // Right now the only operations block, so the while loop is pointless
55 // but leaving it in, just in case that ever changes.
56 while (fdp.remaining_bytes() > sizeof(MessageInfo)) {
57 opt = fdp.ConsumeIntegral<uint8_t>() % dispatcher_operations.size();
58 dispatcher_operations[opt](dispatcher, &fdp);
59 }
60 });
61
62 // Continuously wake up the epoll so the dispatcher can run.
63 while (fdp.remaining_bytes() > sizeof(MessageInfo)) {
64 eventfd_write(endpoint->epoll_fd(), wakeup_val);
65 }
66
67 // Cleanup the dispatcher and thread.
68 dispatcher->SetCanceled(true);
69 if (run_dispatcher.joinable())
70 run_dispatcher.join();
71 dispatcher->RemoveService(service);
72
73 return 0;
74 }
75