Implement FUSE_OPEN/OPENDIR

Fixes #3174

5 files changed, 175 insertions, 26 deletions

diff --git a/test/fuse/BUILD b/test/fuse/BUILD
index 385920e17..209030ff1 100644
--- a/test/fuse/BUILD
+++ b/test/fuse/BUILD
@@ -6,3 +6,8 @@ syscall_test(
     fuse = "True",
     test = "//test/fuse/linux:stat_test",
 )
+
+syscall_test(
+    fuse = "True",
+    test = "//test/fuse/linux:open_test",
+)
diff --git a/test/fuse/linux/BUILD b/test/fuse/linux/BUILD
index e4a614e11..1d989a2f4 100644
--- a/test/fuse/linux/BUILD
+++ b/test/fuse/linux/BUILD
@@ -18,6 +18,19 @@ cc_binary(
     ],
 )
 
+cc_binary(
+    name = "open_test",
+    testonly = 1,
+    srcs = ["open_test.cc"],
+    deps = [
+        gtest,
+        ":fuse_base",
+        "//test/util:fuse_util",
+        "//test/util:test_main",
+        "//test/util:test_util",
+    ],
+)
+
 cc_library(
     name = "fuse_base",
     testonly = 1,
diff --git a/test/fuse/linux/fuse_base.cc b/test/fuse/linux/fuse_base.cc
index a9fe1044e..e734100b1 100644
--- a/test/fuse/linux/fuse_base.cc
+++ b/test/fuse/linux/fuse_base.cc
@@ -117,6 +117,16 @@ uint32_t FuseTest::GetServerTotalReceivedBytes() {
       static_cast<uint32_t>(FuseTestCmd::kGetTotalReceivedBytes));
 }
 
+// Sends the `kSkipRequest` command to the FUSE server, which would skip
+// current stored request data.
+void FuseTest::SkipServerActualRequest() {
+  uint32_t cmd = static_cast<uint32_t>(FuseTestCmd::kSkipRequest);
+  EXPECT_THAT(RetryEINTR(write)(sock_[0], &cmd, sizeof(cmd)),
+              SyscallSucceedsWithValue(sizeof(cmd)));
+
+  WaitServerComplete();
+}
+
 // Sends the `kSetInodeLookup` command, expected mode, and the path of the
 // inode to create under the mount point.
 void FuseTest::SetServerInodeLookup(const std::string& path, mode_t mode) {
@@ -284,6 +294,9 @@ void FuseTest::ServerHandleCommand() {
     case FuseTestCmd::kGetNumUnsentResponses:
       ServerSendData(static_cast<uint32_t>(responses_.RemainingBlocks()));
       break;
+    case FuseTestCmd::kSkipRequest:
+      ServerSkipReceivedRequest();
+      break;
     default:
       FAIL() << "Unknown FuseTestCmd " << cmd;
       break;
@@ -314,32 +327,7 @@ void FuseTest::ServerReceiveInodeLookup() {
       .len = out_len,
       .error = 0,
   };
-  struct fuse_entry_out out_payload = {
-      .nodeid = nodeid_,
-      .generation = 0,
-      .entry_valid = 0,
-      .attr_valid = 0,
-      .entry_valid_nsec = 0,
-      .attr_valid_nsec = 0,
-      .attr =
-          (struct fuse_attr){
-              .ino = nodeid_,
-              .size = 512,
-              .blocks = 4,
-              .atime = 0,
-              .mtime = 0,
-              .ctime = 0,
-              .atimensec = 0,
-              .mtimensec = 0,
-              .ctimensec = 0,
-              .mode = mode,
-              .nlink = 2,
-              .uid = 1234,
-              .gid = 4321,
-              .rdev = 12,
-              .blksize = 4096,
-          },
-  };
+  struct fuse_entry_out out_payload = DefaultEntryOut(mode, nodeid_);
   // Since this is only used in test, nodeid_ is simply increased by 1 to
   // comply with the unqiueness of different path.
   ++nodeid_;
@@ -363,6 +351,15 @@ void FuseTest::ServerSendReceivedRequest() {
       SyscallSucceedsWithValue(mem_block.len));
 }
 
+// Skip the request pointed by current cursor.
+void FuseTest::ServerSkipReceivedRequest() {
+  if (requests_.End()) {
+    FAIL() << "No more received request.";
+    return;
+  }
+  requests_.Next();
+}
+
 // Handles FUSE request. Reads request from /dev/fuse, checks if it has the
 // same opcode as expected, and responds with the saved fake FUSE response.
 // The FUSE request is copied to the serial buffer and can be retrieved one-
@@ -390,6 +387,7 @@ void FuseTest::ServerProcessFuseRequest() {
 
   requests_.AddMemBlock(in_header->opcode, buf.data(), len);
 
+  if (in_header->opcode == FUSE_RELEASE) return;
   // Check if there is a corresponding response.
   if (responses_.End()) {
     GTEST_NONFATAL_FAILURE_("No more FUSE response is expected");
diff --git a/test/fuse/linux/fuse_base.h b/test/fuse/linux/fuse_base.h
index a21b4bb8d..2474b763f 100644
--- a/test/fuse/linux/fuse_base.h
+++ b/test/fuse/linux/fuse_base.h
@@ -42,6 +42,7 @@ enum class FuseTestCmd {
   kGetNumUnconsumedRequests,
   kGetNumUnsentResponses,
   kGetTotalReceivedBytes,
+  kSkipRequest,
 };
 
 // Holds the information of a memory block in a serial buffer.
@@ -158,6 +159,10 @@ class FuseTest : public ::testing::Test {
   // bytes from /dev/fuse.
   uint32_t GetServerTotalReceivedBytes();
 
+  // Called by the testing thread to ask the FUSE server to skip stored
+  // request data.
+  void SkipServerActualRequest();
+
  protected:
   TempPath mount_point_;
 
@@ -211,6 +216,10 @@ class FuseTest : public ::testing::Test {
   // Sends a uint32_t data via socket.
   inline void ServerSendData(uint32_t data);
 
+  // The FUSE server side's corresponding code of `SkipServerActualRequest()`.
+  // Handles `kSkipRequest` command. Skip the request pointed by current cursor.
+  void ServerSkipReceivedRequest();
+
   // Handles FUSE request sent to /dev/fuse by its saved responses.
   void ServerProcessFuseRequest();
 
diff --git a/test/fuse/linux/open_test.cc b/test/fuse/linux/open_test.cc
new file mode 100644
index 000000000..ed0641587
--- /dev/null
+++ b/test/fuse/linux/open_test.cc
@@ -0,0 +1,124 @@
+// 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.
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/fuse.h>
+#include <sys/stat.h>
+#include <sys/statfs.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <string>
+
+#include "gtest/gtest.h"
+#include "test/fuse/linux/fuse_base.h"
+#include "test/util/fuse_util.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+class OpenTest : public FuseTest {
+ protected:
+  const std::string test_file_ = "test_file";
+  const mode_t regular_file_ = S_IFREG | S_IRWXU | S_IRWXG | S_IRWXO;
+
+  struct fuse_open_out out_payload_ = {
+      .fh = 1,
+      .open_flags = O_RDWR,
+  };
+};
+
+TEST_F(OpenTest, RegularFile) {
+  const std::string test_file_path =
+      JoinPath(mount_point_.path().c_str(), test_file_);
+  SetServerInodeLookup(test_file_, regular_file_);
+
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_open_out),
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload_);
+  SetServerResponse(FUSE_OPEN, iov_out);
+  FileDescriptor fd =
+      ASSERT_NO_ERRNO_AND_VALUE(Open(test_file_path.c_str(), O_RDWR));
+
+  struct fuse_in_header in_header;
+  struct fuse_open_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+  GetServerActualRequest(iov_in);
+
+  EXPECT_EQ(in_header.len, sizeof(in_header) + sizeof(in_payload));
+  EXPECT_EQ(in_header.opcode, FUSE_OPEN);
+  EXPECT_EQ(in_payload.flags, O_RDWR);
+  EXPECT_THAT(fcntl(fd.get(), F_GETFL), SyscallSucceedsWithValue(O_RDWR));
+}
+
+TEST_F(OpenTest, SetNoOpen) {
+  const std::string test_file_path =
+      JoinPath(mount_point_.path().c_str(), test_file_);
+  SetServerInodeLookup(test_file_, regular_file_);
+
+  // ENOSYS indicates open is not implemented.
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_open_out),
+      .error = -ENOSYS,
+  };
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload_);
+  SetServerResponse(FUSE_OPEN, iov_out);
+  ASSERT_NO_ERRNO_AND_VALUE(Open(test_file_path.c_str(), O_RDWR));
+  SkipServerActualRequest();
+
+  // check open doesn't send new request.
+  uint32_t recieved_before = GetServerTotalReceivedBytes();
+  ASSERT_NO_ERRNO_AND_VALUE(Open(test_file_path.c_str(), O_RDWR));
+  EXPECT_EQ(GetServerTotalReceivedBytes(), recieved_before);
+}
+
+TEST_F(OpenTest, OpenFail) {
+  struct fuse_out_header out_header = {
+      .len = sizeof(struct fuse_out_header) + sizeof(struct fuse_open_out),
+      .error = -ENOENT,
+  };
+
+  auto iov_out = FuseGenerateIovecs(out_header, out_payload_);
+  SetServerResponse(FUSE_OPENDIR, iov_out);
+  ASSERT_THAT(open(mount_point_.path().c_str(), O_RDWR),
+              SyscallFailsWithErrno(ENOENT));
+
+  struct fuse_in_header in_header;
+  struct fuse_open_in in_payload;
+  auto iov_in = FuseGenerateIovecs(in_header, in_payload);
+  GetServerActualRequest(iov_in);
+
+  EXPECT_EQ(in_header.len, sizeof(in_header) + sizeof(in_payload));
+  EXPECT_EQ(in_header.opcode, FUSE_OPENDIR);
+  EXPECT_EQ(in_payload.flags, O_RDWR);
+}
+
+TEST_F(OpenTest, DirectoryFlagOnRegularFile) {
+  const std::string test_file_path =
+      JoinPath(mount_point_.path().c_str(), test_file_);
+
+  SetServerInodeLookup(test_file_, regular_file_);
+  ASSERT_THAT(open(test_file_path.c_str(), O_RDWR | O_DIRECTORY),
+              SyscallFailsWithErrno(ENOTDIR));
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor