Add FUSE integration test

This commit adds an integration test framework for FUSE support. Please
refer to the test example and test/fuse/README.md for further details.

Fixes #3098

1 files changed, 97 insertions, 0 deletions

diff --git a/test/fuse/linux/fuse_base.h b/test/fuse/linux/fuse_base.h
new file mode 100644
index 000000000..b008778de
--- /dev/null
+++ b/test/fuse/linux/fuse_base.h
@@ -0,0 +1,97 @@
+// Copyright 2020 The gVisor Authors.
+//
+// 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.
+
+#ifndef GVISOR_TEST_FUSE_FUSE_BASE_H_
+#define GVISOR_TEST_FUSE_FUSE_BASE_H_
+
+#include <linux/fuse.h>
+#include <sys/uio.h>
+
+#include <vector>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "test/util/posix_error.h"
+
+namespace gvisor {
+namespace testing {
+
+constexpr char kMountPoint[] = "/mnt";
+constexpr char kMountOpts[] = "rootmode=755,user_id=0,group_id=0";
+
+class FuseTest : public ::testing::Test {
+ public:
+  FuseTest() {
+    buf_.resize(FUSE_MIN_READ_BUFFER);
+    mem_in_.resize(FUSE_MIN_READ_BUFFER);
+    mem_out_.resize(FUSE_MIN_READ_BUFFER);
+  }
+  void SetUp() override;
+  void TearDown() override;
+
+  // CompareRequest is used by the FUSE server and should be implemented to
+  // compare different FUSE operations. It compares the actual FUSE input
+  // request with the expected one set by `SetExpected()`.
+  virtual bool CompareRequest(void* expected_mem, size_t expected_len,
+                              void* real_mem, size_t real_len);
+
+  // SetExpected is called by the testing main thread. Writes a request-
+  // response pair into FUSE server's member variables via pipe.
+  void SetExpected(struct iovec* iov_in, int iov_in_cnt, struct iovec* iov_out,
+                   int iov_out_cnt);
+
+  // WaitCompleted waits for FUSE server to complete its processing. It
+  // complains if the FUSE server responds failure during tests.
+  void WaitCompleted();
+
+ private:
+  void MountFuse();
+  void UnmountFuse();
+
+  // ConsumeFuseInit is only used during FUSE server setup.
+  PosixError ConsumeFuseInit();
+
+  // ReceiveExpected is the FUSE server side's corresponding code of
+  // `SetExpected()`. Save the request-response pair into its memory.
+  void ReceiveExpected();
+
+  // MarkDone is used by the FUSE server to tell testing main if it's OK to
+  // proceed next command.
+  void MarkDone(bool success);
+
+  // FuseLoop is where the FUSE server stay until it is terminated.
+  void FuseLoop();
+
+  // SetUpFuseServer creates 2 pipes for communication and forks FUSE server.
+  void SetUpFuseServer();
+
+  // GetPayloadSize is a helper function to get the number of bytes of a
+  // specific FUSE operation struct.
+  size_t GetPayloadSize(uint32_t opcode, bool in);
+
+  int dev_fd_;
+  int set_expected_[2];
+  int done_[2];
+
+  std::vector<char> buf_;
+  std::vector<char> mem_in_;
+  std::vector<char> mem_out_;
+  ssize_t len_in_;
+  ssize_t len_out_;
+};
+
+}  // namespace testing
+}  // namespace gvisor
+
+#endif  // GVISOR_TEST_FUSE_FUSE_BASE_H_