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// Copyright 2018 Google LLC
//
// 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 <sys/eventfd.h>
#include <unistd.h>
#include "gtest/gtest.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) {
FileDescriptor nfd;
// Open an eventfd file descriptor with FD_CLOEXEC descriptor flag set.
int event_fd = 0;
ASSERT_THAT(event_fd = eventfd(0, EFD_CLOEXEC), SyscallSucceeds());
FileDescriptor event_fd_closer(event_fd);
EXPECT_THAT(fcntl(event_fd_closer.get(), F_GETFD),
SyscallSucceedsWithValue(FD_CLOEXEC));
// Duplicate the descriptor. Ensure that it doesn't have FD_CLOEXEC set.
nfd = ASSERT_NO_ERRNO_AND_VALUE(event_fd_closer.Dup());
ASSERT_NE(event_fd_closer.get(), nfd.get());
CheckSameFile(event_fd_closer, 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
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