// 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 <sys/syscall.h> #include <sys/types.h> #include <sys/uio.h> #include <string> #include <vector> #include "gtest/gtest.h" #include "absl/memory/memory.h" #include "test/syscalls/linux/file_base.h" #include "test/util/file_descriptor.h" #include "test/util/temp_path.h" #include "test/util/test_util.h" namespace gvisor { namespace testing { namespace { #ifndef SYS_preadv2 #if defined(__x86_64__) #define SYS_preadv2 327 #elif defined(__aarch64__) #define SYS_preadv2 286 #else #error "Unknown architecture" #endif #endif // SYS_preadv2 #ifndef RWF_HIPRI #define RWF_HIPRI 0x1 #endif // RWF_HIPRI constexpr int kBufSize = 1024; std::string SetContent() { std::string content; for (int i = 0; i < kBufSize; i++) { content += static_cast<char>((i % 10) + '0'); } return content; } ssize_t preadv2(unsigned long fd, const struct iovec* iov, unsigned long iovcnt, off_t offset, unsigned long flags) { // syscall on preadv2 does some weird things (see man syscall and search // preadv2), so we insert a 0 to word align the flags argument on native. return syscall(SYS_preadv2, fd, iov, iovcnt, offset, 0, flags); } // This test is the base case where we call preadv (no offset, no flags). TEST(Preadv2Test, TestBaseCall) { SKIP_IF(preadv2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); std::string content = SetContent(); const TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith( GetAbsoluteTestTmpdir(), content, TempPath::kDefaultFileMode)); const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_RDONLY)); std::vector<char> buf(kBufSize); struct iovec iov[2]; iov[0].iov_base = buf.data(); iov[0].iov_len = buf.size() / 2; iov[1].iov_base = static_cast<char*>(iov[0].iov_base) + (content.size() / 2); iov[1].iov_len = content.size() / 2; EXPECT_THAT(preadv2(fd.get(), iov, /*iovcnt*/ 2, /*offset=*/0, /*flags=*/0), SyscallSucceedsWithValue(kBufSize)); EXPECT_EQ(content, std::string(buf.data(), buf.size())); } // This test is where we call preadv with an offset and no flags. TEST(Preadv2Test, TestValidPositiveOffset) { SKIP_IF(preadv2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); std::string content = SetContent(); const std::string prefix = "0"; const TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith( GetAbsoluteTestTmpdir(), prefix + content, TempPath::kDefaultFileMode)); const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_RDONLY)); std::vector<char> buf(kBufSize, '0'); struct iovec iov; iov.iov_base = buf.data(); iov.iov_len = buf.size(); EXPECT_THAT(preadv2(fd.get(), &iov, /*iovcnt=*/1, /*offset=*/prefix.size(), /*flags=*/0), SyscallSucceedsWithValue(kBufSize)); EXPECT_THAT(lseek(fd.get(), 0, SEEK_CUR), SyscallSucceedsWithValue(0)); EXPECT_EQ(content, std::string(buf.data(), buf.size())); } // This test is the base case where we call readv by using -1 as the offset. The // read should use the file offset, so the test increments it by one prior to // calling preadv2. TEST(Preadv2Test, TestNegativeOneOffset) { SKIP_IF(preadv2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); std::string content = SetContent(); const std::string prefix = "231"; const TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith( GetAbsoluteTestTmpdir(), prefix + content, TempPath::kDefaultFileMode)); const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_RDONLY)); ASSERT_THAT(lseek(fd.get(), prefix.size(), SEEK_SET), SyscallSucceedsWithValue(prefix.size())); std::vector<char> buf(kBufSize, '0'); struct iovec iov; iov.iov_base = buf.data(); iov.iov_len = buf.size(); EXPECT_THAT(preadv2(fd.get(), &iov, /*iovcnt=*/1, /*offset=*/-1, /*flags=*/0), SyscallSucceedsWithValue(kBufSize)); EXPECT_THAT(lseek(fd.get(), 0, SEEK_CUR), SyscallSucceedsWithValue(prefix.size() + buf.size())); EXPECT_EQ(content, std::string(buf.data(), buf.size())); } // preadv2 requires if the RWF_HIPRI flag is passed, the fd must be opened with // O_DIRECT. This test implements a correct call with the RWF_HIPRI flag. TEST(Preadv2Test, TestCallWithRWF_HIPRI) { SKIP_IF(preadv2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); std::string content = SetContent(); const TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith( GetAbsoluteTestTmpdir(), content, TempPath::kDefaultFileMode)); const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_RDONLY)); EXPECT_THAT(fsync(fd.get()), SyscallSucceeds()); std::vector<char> buf(kBufSize, '0'); struct iovec iov; iov.iov_base = buf.data(); iov.iov_len = buf.size(); EXPECT_THAT( preadv2(fd.get(), &iov, /*iovcnt=*/1, /*offset=*/0, /*flags=*/RWF_HIPRI), SyscallSucceedsWithValue(kBufSize)); EXPECT_THAT(lseek(fd.get(), 0, SEEK_CUR), SyscallSucceedsWithValue(0)); EXPECT_EQ(content, std::string(buf.data(), buf.size())); } // This test calls preadv2 with an invalid flag. TEST(Preadv2Test, TestInvalidFlag) { SKIP_IF(preadv2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); const TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith( GetAbsoluteTestTmpdir(), "", TempPath::kDefaultFileMode)); const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_RDONLY | O_DIRECT)); std::vector<char> buf(kBufSize, '0'); struct iovec iov; iov.iov_base = buf.data(); iov.iov_len = buf.size(); EXPECT_THAT(preadv2(fd.get(), &iov, /*iovcnt=*/1, /*offset=*/0, /*flags=*/0xF0), SyscallFailsWithErrno(EOPNOTSUPP)); } // This test calls preadv2 with an invalid offset. TEST(Preadv2Test, TestInvalidOffset) { SKIP_IF(preadv2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); const TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith( GetAbsoluteTestTmpdir(), "", TempPath::kDefaultFileMode)); const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_RDONLY | O_DIRECT)); auto iov = absl::make_unique<struct iovec[]>(1); iov[0].iov_base = nullptr; iov[0].iov_len = 0; EXPECT_THAT(preadv2(fd.get(), iov.get(), /*iovcnt=*/1, /*offset=*/-8, /*flags=*/0), SyscallFailsWithErrno(EINVAL)); } // This test calls preadv with a file set O_WRONLY. TEST(Preadv2Test, TestUnreadableFile) { SKIP_IF(preadv2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); const TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith( GetAbsoluteTestTmpdir(), "", TempPath::kDefaultFileMode)); const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_WRONLY)); auto iov = absl::make_unique<struct iovec[]>(1); iov[0].iov_base = nullptr; iov[0].iov_len = 0; EXPECT_THAT(preadv2(fd.get(), iov.get(), /*iovcnt=*/1, /*offset=*/0, /*flags=*/0), SyscallFailsWithErrno(EBADF)); } // Calling preadv2 with a non-negative offset calls preadv. Calling preadv with // an unseekable file is not allowed. A pipe is used for an unseekable file. TEST(Preadv2Test, TestUnseekableFileInvalid) { SKIP_IF(preadv2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); int pipe_fds[2]; ASSERT_THAT(pipe(pipe_fds), SyscallSucceeds()); auto iov = absl::make_unique<struct iovec[]>(1); iov[0].iov_base = nullptr; iov[0].iov_len = 0; EXPECT_THAT(preadv2(pipe_fds[0], iov.get(), /*iovcnt=*/1, /*offset=*/2, /*flags=*/0), SyscallFailsWithErrno(ESPIPE)); EXPECT_THAT(close(pipe_fds[0]), SyscallSucceeds()); EXPECT_THAT(close(pipe_fds[1]), SyscallSucceeds()); } TEST(Preadv2Test, TestUnseekableFileValid) { SKIP_IF(preadv2(-1, nullptr, 0, 0, 0) < 0 && errno == ENOSYS); int pipe_fds[2]; ASSERT_THAT(pipe(pipe_fds), SyscallSucceeds()); std::vector<char> content(32, 'X'); EXPECT_THAT(write(pipe_fds[1], content.data(), content.size()), SyscallSucceedsWithValue(content.size())); std::vector<char> buf(content.size()); auto iov = absl::make_unique<struct iovec[]>(1); iov[0].iov_base = buf.data(); iov[0].iov_len = buf.size(); EXPECT_THAT(preadv2(pipe_fds[0], iov.get(), /*iovcnt=*/1, /*offset=*/static_cast<off_t>(-1), /*flags=*/0), SyscallSucceedsWithValue(buf.size())); EXPECT_EQ(content, buf); EXPECT_THAT(close(pipe_fds[0]), SyscallSucceeds()); EXPECT_THAT(close(pipe_fds[1]), SyscallSucceeds()); } } // namespace } // namespace testing } // namespace gvisor