1 files changed, 133 insertions, 0 deletions
diff --git a/test/syscalls/linux/dup.cc b/test/syscalls/linux/dup.cc
new file mode 100644
index 000000000..4f773bc75
--- /dev/null
+++ b/test/syscalls/linux/dup.cc
@@ -0,0 +1,133 @@
+// Copyright 2018 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 <fcntl.h>
+#include <unistd.h>
+
+#include "gtest/gtest.h"
+#include "test/util/eventfd_util.h"
+#include "test/util/file_descriptor.h"
+#include "test/util/posix_error.h"
+#include "test/util/temp_path.h"
+#include "test/util/test_util.h"
+
+namespace gvisor {
+namespace testing {
+
+namespace {
+
+PosixErrorOr<FileDescriptor> Dup2(const FileDescriptor& fd, int target_fd) {
+  int new_fd = dup2(fd.get(), target_fd);
+  if (new_fd < 0) {
+    return PosixError(errno, "Dup2");
+  }
+  return FileDescriptor(new_fd);
+}
+
+PosixErrorOr<FileDescriptor> Dup3(const FileDescriptor& fd, int target_fd,
+                                  int flags) {
+  int new_fd = dup3(fd.get(), target_fd, flags);
+  if (new_fd < 0) {
+    return PosixError(errno, "Dup2");
+  }
+  return FileDescriptor(new_fd);
+}
+
+void CheckSameFile(const FileDescriptor& fd1, const FileDescriptor& fd2) {
+  struct stat stat_result1, stat_result2;
+  ASSERT_THAT(fstat(fd1.get(), &stat_result1), SyscallSucceeds());
+  ASSERT_THAT(fstat(fd2.get(), &stat_result2), SyscallSucceeds());
+  EXPECT_EQ(stat_result1.st_dev, stat_result2.st_dev);
+  EXPECT_EQ(stat_result1.st_ino, stat_result2.st_ino);
+}
+
+TEST(DupTest, Dup) {
+  auto f = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile());
+  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(f.path(), O_RDONLY));
+
+  // Dup the descriptor and make sure it's the same file.
+  FileDescriptor nfd = ASSERT_NO_ERRNO_AND_VALUE(fd.Dup());
+  ASSERT_NE(fd.get(), nfd.get());
+  CheckSameFile(fd, nfd);
+}
+
+TEST(DupTest, DupClearsCloExec) {
+  // Open an eventfd file descriptor with FD_CLOEXEC descriptor flag set.
+  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(NewEventFD(0, EFD_CLOEXEC));
+  EXPECT_THAT(fcntl(fd.get(), F_GETFD), SyscallSucceedsWithValue(FD_CLOEXEC));
+
+  // Duplicate the descriptor. Ensure that it doesn't have FD_CLOEXEC set.
+  FileDescriptor nfd = ASSERT_NO_ERRNO_AND_VALUE(fd.Dup());
+  ASSERT_NE(fd.get(), nfd.get());
+  CheckSameFile(fd, nfd);
+  EXPECT_THAT(fcntl(nfd.get(), F_GETFD), SyscallSucceedsWithValue(0));
+}
+
+TEST(DupTest, Dup2) {
+  auto f = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile());
+  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(f.path(), O_RDONLY));
+
+  // Regular dup once.
+  FileDescriptor nfd = ASSERT_NO_ERRNO_AND_VALUE(fd.Dup());
+
+  ASSERT_NE(fd.get(), nfd.get());
+  CheckSameFile(fd, nfd);
+
+  // Dup over the file above.
+  int target_fd = nfd.release();
+  FileDescriptor nfd2 = ASSERT_NO_ERRNO_AND_VALUE(Dup2(fd, target_fd));
+  EXPECT_EQ(target_fd, nfd2.get());
+  CheckSameFile(fd, nfd2);
+}
+
+TEST(DupTest, Dup2SameFD) {
+  auto f = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile());
+  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(f.path(), O_RDONLY));
+
+  // Should succeed.
+  ASSERT_THAT(dup2(fd.get(), fd.get()), SyscallSucceedsWithValue(fd.get()));
+}
+
+TEST(DupTest, Dup3) {
+  auto f = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile());
+  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(f.path(), O_RDONLY));
+
+  // Regular dup once.
+  FileDescriptor nfd = ASSERT_NO_ERRNO_AND_VALUE(fd.Dup());
+  ASSERT_NE(fd.get(), nfd.get());
+  CheckSameFile(fd, nfd);
+
+  // Dup over the file above, check that it has no CLOEXEC.
+  nfd = ASSERT_NO_ERRNO_AND_VALUE(Dup3(fd, nfd.release(), 0));
+  CheckSameFile(fd, nfd);
+  EXPECT_THAT(fcntl(nfd.get(), F_GETFD), SyscallSucceedsWithValue(0));
+
+  // Dup over the file again, check that it does not CLOEXEC.
+  nfd = ASSERT_NO_ERRNO_AND_VALUE(Dup3(fd, nfd.release(), O_CLOEXEC));
+  CheckSameFile(fd, nfd);
+  EXPECT_THAT(fcntl(nfd.get(), F_GETFD), SyscallSucceedsWithValue(FD_CLOEXEC));
+}
+
+TEST(DupTest, Dup3FailsSameFD) {
+  auto f = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile());
+  FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(f.path(), O_RDONLY));
+
+  // Only dup3 fails if the new and old fd are the same.
+  ASSERT_THAT(dup3(fd.get(), fd.get(), 0), SyscallFailsWithErrno(EINVAL));
+}
+
+}  // namespace
+
+}  // namespace testing
+}  // namespace gvisor