1 files changed, 294 insertions, 0 deletions
diff --git a/libs/vr/libpdx/fuzz/helpers.h b/libs/vr/libpdx/fuzz/helpers.h
new file mode 100644
index 0000000000..83ec4096f6
--- /dev/null
+++ b/libs/vr/libpdx/fuzz/helpers.h
@@ -0,0 +1,294 @@
+/*
+ * Copyright 2020 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.
+ */
+// Authors: corbin.souffrant@leviathansecurity.com
+//          brian.balling@leviathansecurity.com
+
+#ifndef LEV_FUZZERS_LIBPDX_HELPERS_H_
+#define LEV_FUZZERS_LIBPDX_HELPERS_H_
+
+#define UNUSED(expr) \
+  do {               \
+    (void)(expr);    \
+  } while (0)
+
+#include <fuzzer/FuzzedDataProvider.h>
+#include <pdx/client.h>
+#include <pdx/service.h>
+#include <pdx/service_dispatcher.h>
+#include <pdx/service_endpoint.h>
+#include <sys/eventfd.h>
+#include <memory>
+#include <vector>
+
+using namespace android::pdx;
+
+// Vector of operations we can call in the dispatcher.
+static const std::vector<std::function<void(
+    const std::unique_ptr<ServiceDispatcher>&, FuzzedDataProvider*)>>
+    dispatcher_operations = {
+        [](const std::unique_ptr<ServiceDispatcher>& dispatcher,
+           FuzzedDataProvider*) -> void { dispatcher->EnterDispatchLoop(); },
+        [](const std::unique_ptr<ServiceDispatcher>& dispatcher,
+           FuzzedDataProvider*) -> void { dispatcher->ReceiveAndDispatch(); },
+        [](const std::unique_ptr<ServiceDispatcher>& dispatcher,
+           FuzzedDataProvider* fdp) -> void {
+          dispatcher->ReceiveAndDispatch(fdp->ConsumeIntegral<int>());
+        }};
+
+// Most of the fuzzing occurs within the endpoint, which is derived from an
+// abstract class. So we are returning garbage data for most functions besides
+// the ones we added or need to actually use.
+class FuzzEndpoint : public Endpoint {
+ public:
+  explicit FuzzEndpoint(FuzzedDataProvider* fdp) {
+    _fdp = fdp;
+    _epoll_fd = eventfd(0, 0);
+  }
+
+  ~FuzzEndpoint() { close(_epoll_fd); }
+
+  // Returns an fd that can be used with epoll() to wait for incoming messages
+  // from this endpoint.
+  int epoll_fd() const { return _epoll_fd; }
+
+  // Associates a Service instance with an endpoint by setting the service
+  // context pointer to the address of the Service. Only one Service may be
+  // associated with a given endpoint.
+  Status<void> SetService(Service* service) {
+    _service = service;
+    return Status<void>(0);
+  }
+
+  // Set the channel context for the given channel.
+  Status<void> SetChannel(int channel_id, Channel* channel) {
+    UNUSED(channel_id);
+    _channel = std::shared_ptr<Channel>(channel);
+    return Status<void>(0);
+  }
+
+  // Receives a message on the given endpoint file descriptor.
+  // This is called by the dispatcher to determine what operations
+  // to make, so we are fuzzing the response.
+  Status<void> MessageReceive(Message* message) {
+    // Create a randomized MessageInfo struct.
+    MessageInfo info;
+    eventfd_t wakeup_val = 0;
+    info.pid = _fdp->ConsumeIntegral<int>();
+    info.tid = _fdp->ConsumeIntegral<int>();
+    info.cid = _fdp->ConsumeIntegral<int>();
+    info.mid = _fdp->ConsumeIntegral<int>();
+    info.euid = _fdp->ConsumeIntegral<int>();
+    info.egid = _fdp->ConsumeIntegral<int>();
+    info.op = _fdp->ConsumeIntegral<int32_t>();
+    info.flags = _fdp->ConsumeIntegral<uint32_t>();
+    info.service = _service;
+    info.channel = _channel.get();
+    info.send_len = _fdp->ConsumeIntegral<size_t>();
+    info.recv_len = _fdp->ConsumeIntegral<size_t>();
+    info.fd_count = _fdp->ConsumeIntegral<size_t>();
+    if (_fdp->remaining_bytes() >= 32) {
+      std::vector<uint8_t> impulse_vec = _fdp->ConsumeBytes<uint8_t>(32);
+      memcpy(info.impulse, impulse_vec.data(), 32);
+    }
+
+    *message = Message(info);
+    eventfd_read(_epoll_fd, &wakeup_val);
+
+    return Status<void>();
+  }
+
+  // Returns a tag that uniquely identifies a specific underlying IPC
+  // transport.
+  uint32_t GetIpcTag() const { return 0; }
+
+  // Close a channel, signaling the client file object and freeing the channel
+  // id. Once closed, the client side of the channel always returns the error
+  // ESHUTDOWN and signals the poll/epoll events POLLHUP and POLLFREE.
+  Status<void> CloseChannel(int channel_id) {
+    UNUSED(channel_id);
+    return Status<void>();
+  }
+
+  // Update the event bits for the given channel (given by id), using the
+  // given clear and set masks.
+  Status<void> ModifyChannelEvents(int channel_id, int clear_mask,
+                                   int set_mask) {
+    UNUSED(channel_id);
+    UNUSED(clear_mask);
+    UNUSED(set_mask);
+    return Status<void>();
+  }
+
+  // Create a new channel and push it as a file descriptor to the process
+  // sending the |message|. |flags| may be set to O_NONBLOCK and/or
+  // O_CLOEXEC to control the initial behavior of the new file descriptor (the
+  // sending process may change these later using fcntl()). The internal
+  // Channel instance associated with this channel is set to |channel|,
+  // which may be nullptr. The new channel id allocated for this channel is
+  // returned in |channel_id|, which may also be nullptr if not needed.
+  Status<RemoteChannelHandle> PushChannel(Message* message, int flags,
+                                          Channel* channel, int* channel_id) {
+    UNUSED(message);
+    UNUSED(flags);
+    UNUSED(channel);
+    UNUSED(channel_id);
+    return Status<RemoteChannelHandle>();
+  }
+
+  // Check whether the |ref| is a reference to a channel to the service
+  // represented by the |endpoint|. If the channel reference in question is
+  // valid, the Channel object is returned in |channel| when non-nullptr and
+  // the channel ID is returned through the Status object.
+  Status<int> CheckChannel(const Message* message, ChannelReference ref,
+                           Channel** channel) {
+    UNUSED(message);
+    UNUSED(ref);
+    UNUSED(channel);
+    return Status<int>();
+  }
+
+  // Replies to the message with a return code.
+  Status<void> MessageReply(Message* message, int return_code) {
+    UNUSED(message);
+    UNUSED(return_code);
+    return Status<void>();
+  }
+
+  // Replies to the message with a file descriptor.
+  Status<void> MessageReplyFd(Message* message, unsigned int push_fd) {
+    UNUSED(message);
+    UNUSED(push_fd);
+    return Status<void>();
+  }
+
+  // Replies to the message with a local channel handle.
+  Status<void> MessageReplyChannelHandle(Message* message,
+                                         const LocalChannelHandle& handle) {
+    UNUSED(message);
+    UNUSED(handle);
+    return Status<void>();
+  }
+
+  // Replies to the message with a borrowed local channel handle.
+  Status<void> MessageReplyChannelHandle(Message* message,
+                                         const BorrowedChannelHandle& handle) {
+    UNUSED(message);
+    UNUSED(handle);
+    return Status<void>();
+  }
+
+  // Replies to the message with a remote channel handle.
+  Status<void> MessageReplyChannelHandle(Message* message,
+                                         const RemoteChannelHandle& handle) {
+    UNUSED(message);
+    UNUSED(handle);
+    return Status<void>();
+  }
+
+  // Reads message data into an array of memory buffers.
+  Status<size_t> ReadMessageData(Message* message, const iovec* vector,
+                                 size_t vector_length) {
+    UNUSED(message);
+    UNUSED(vector);
+    UNUSED(vector_length);
+    return Status<size_t>();
+  }
+
+  // Sends reply data for message.
+  Status<size_t> WriteMessageData(Message* message, const iovec* vector,
+                                  size_t vector_length) {
+    UNUSED(message);
+    UNUSED(vector);
+    UNUSED(vector_length);
+    return Status<size_t>();
+  }
+
+  // Records a file descriptor into the message buffer and returns the
+  // remapped reference to be sent to the remote process.
+  Status<FileReference> PushFileHandle(Message* message,
+                                       const LocalHandle& handle) {
+    UNUSED(message);
+    UNUSED(handle);
+    return Status<FileReference>();
+  }
+
+  Status<FileReference> PushFileHandle(Message* message,
+                                       const BorrowedHandle& handle) {
+    UNUSED(message);
+    UNUSED(handle);
+    return Status<FileReference>();
+  }
+
+  Status<FileReference> PushFileHandle(Message* message,
+                                       const RemoteHandle& handle) {
+    UNUSED(message);
+    UNUSED(handle);
+    return Status<FileReference>();
+  }
+
+  Status<ChannelReference> PushChannelHandle(Message* message,
+                                             const LocalChannelHandle& handle) {
+    UNUSED(message);
+    UNUSED(handle);
+    return Status<ChannelReference>();
+  }
+
+  Status<ChannelReference> PushChannelHandle(
+      Message* message, const BorrowedChannelHandle& handle) {
+    UNUSED(message);
+    UNUSED(handle);
+    return Status<ChannelReference>();
+  }
+
+  Status<ChannelReference> PushChannelHandle(
+      Message* message, const RemoteChannelHandle& handle) {
+    UNUSED(message);
+    UNUSED(handle);
+    return Status<ChannelReference>();
+  }
+
+  // Obtains a file descriptor/channel handle from a message for the given
+  // reference.
+  LocalHandle GetFileHandle(Message* message, FileReference ref) const {
+    UNUSED(message);
+    UNUSED(ref);
+    return LocalHandle();
+  }
+
+  LocalChannelHandle GetChannelHandle(Message* message,
+                                      ChannelReference ref) const {
+    UNUSED(message);
+    UNUSED(ref);
+    return LocalChannelHandle();
+  }
+
+  // Transport-specific message state management.
+  void* AllocateMessageState() { return nullptr; }
+
+  void FreeMessageState(void* state) { UNUSED(state); }
+
+  // Cancels the endpoint, unblocking any receiver threads waiting for a
+  // message.
+  Status<void> Cancel() { return Status<void>(); }
+
+ private:
+  FuzzedDataProvider* _fdp;
+  std::shared_ptr<Channel> _channel;
+  Service* _service;
+  int _epoll_fd;
+};
+
+#endif  // LEV_FUZZERS_LIBPDX_HELPERS_H_