// 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/stat.h> #include <sys/types.h> #include <unistd.h> #include <vector> #include "gmock/gmock.h" #include "gtest/gtest.h" #include "test/util/file_descriptor.h" #include "test/util/test_util.h" namespace gvisor { namespace testing { namespace { TEST(DevTest, LseekDevUrandom) { const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/urandom", O_RDONLY)); EXPECT_THAT(lseek(fd.get(), -10, SEEK_CUR), SyscallSucceeds()); EXPECT_THAT(lseek(fd.get(), -10, SEEK_SET), SyscallSucceeds()); EXPECT_THAT(lseek(fd.get(), 0, SEEK_CUR), SyscallSucceeds()); } TEST(DevTest, LseekDevNull) { const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/null", O_RDONLY)); EXPECT_THAT(lseek(fd.get(), -10, SEEK_CUR), SyscallSucceeds()); EXPECT_THAT(lseek(fd.get(), -10, SEEK_SET), SyscallSucceeds()); EXPECT_THAT(lseek(fd.get(), 0, SEEK_CUR), SyscallSucceeds()); EXPECT_THAT(lseek(fd.get(), 0, SEEK_END), SyscallSucceeds()); } TEST(DevTest, LseekDevZero) { const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/zero", O_RDONLY)); EXPECT_THAT(lseek(fd.get(), 0, SEEK_CUR), SyscallSucceeds()); EXPECT_THAT(lseek(fd.get(), 0, SEEK_END), SyscallSucceeds()); } TEST(DevTest, LseekDevFull) { const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/full", O_RDONLY)); EXPECT_THAT(lseek(fd.get(), 123, SEEK_SET), SyscallSucceedsWithValue(0)); EXPECT_THAT(lseek(fd.get(), 123, SEEK_CUR), SyscallSucceedsWithValue(0)); EXPECT_THAT(lseek(fd.get(), 123, SEEK_END), SyscallSucceedsWithValue(0)); } TEST(DevTest, LseekDevNullFreshFile) { // Seeks to /dev/null always return 0. const FileDescriptor fd1 = ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/null", O_RDONLY)); const FileDescriptor fd2 = ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/null", O_RDONLY)); EXPECT_THAT(lseek(fd1.get(), 0, SEEK_CUR), SyscallSucceedsWithValue(0)); EXPECT_THAT(lseek(fd1.get(), 1000, SEEK_CUR), SyscallSucceedsWithValue(0)); EXPECT_THAT(lseek(fd2.get(), 0, SEEK_CUR), SyscallSucceedsWithValue(0)); const FileDescriptor fd3 = ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/null", O_RDONLY)); EXPECT_THAT(lseek(fd3.get(), 0, SEEK_CUR), SyscallSucceedsWithValue(0)); } TEST(DevTest, OpenTruncate) { // Truncation is ignored on linux and gvisor for device files. ASSERT_NO_ERRNO_AND_VALUE( Open("/dev/null", O_CREAT | O_TRUNC | O_WRONLY, 0644)); ASSERT_NO_ERRNO_AND_VALUE( Open("/dev/zero", O_CREAT | O_TRUNC | O_WRONLY, 0644)); ASSERT_NO_ERRNO_AND_VALUE( Open("/dev/full", O_CREAT | O_TRUNC | O_WRONLY, 0644)); } TEST(DevTest, Pread64DevNull) { const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/null", O_RDONLY)); char buf[1]; EXPECT_THAT(pread64(fd.get(), buf, 1, 0), SyscallSucceedsWithValue(0)); } TEST(DevTest, Pread64DevZero) { const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/zero", O_RDONLY)); char buf[1]; EXPECT_THAT(pread64(fd.get(), buf, 1, 0), SyscallSucceedsWithValue(1)); } TEST(DevTest, Pread64DevFull) { // /dev/full behaves like /dev/zero with respect to reads. const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/full", O_RDONLY)); char buf[1]; EXPECT_THAT(pread64(fd.get(), buf, 1, 0), SyscallSucceedsWithValue(1)); } TEST(DevTest, ReadDevNull) { const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/null", O_RDONLY)); std::vector<char> buf(1); EXPECT_THAT(ReadFd(fd.get(), buf.data(), 1), SyscallSucceeds()); } // Do not allow random save as it could lead to partial reads. TEST(DevTest, ReadDevZero_NoRandomSave) { const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/zero", O_RDONLY)); constexpr int kReadSize = 128 * 1024; std::vector<char> buf(kReadSize, 1); EXPECT_THAT(ReadFd(fd.get(), buf.data(), kReadSize), SyscallSucceedsWithValue(kReadSize)); EXPECT_EQ(std::vector<char>(kReadSize, 0), buf); } TEST(DevTest, WriteDevNull) { const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/null", O_WRONLY)); EXPECT_THAT(WriteFd(fd.get(), "a", 1), SyscallSucceedsWithValue(1)); } TEST(DevTest, WriteDevZero) { const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/zero", O_WRONLY)); EXPECT_THAT(WriteFd(fd.get(), "a", 1), SyscallSucceedsWithValue(1)); } TEST(DevTest, WriteDevFull) { const FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/full", O_WRONLY)); EXPECT_THAT(WriteFd(fd.get(), "a", 1), SyscallFailsWithErrno(ENOSPC)); } TEST(DevTest, TTYExists) { struct stat statbuf = {}; ASSERT_THAT(stat("/dev/tty", &statbuf), SyscallSucceeds()); // Check that it's a character device with rw-rw-rw- permissions. EXPECT_EQ(statbuf.st_mode, S_IFCHR | 0666); } } // namespace } // namespace testing } // namespace gvisor