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Diffstat (limited to 'test/syscalls/linux/stat.cc')
| -rw-r--r-- | test/syscalls/linux/stat.cc | 730 |
1 files changed, 0 insertions, 730 deletions
diff --git a/test/syscalls/linux/stat.cc b/test/syscalls/linux/stat.cc deleted file mode 100644 index 1b2941c37..000000000 --- a/test/syscalls/linux/stat.cc +++ /dev/null @@ -1,730 +0,0 @@ -// 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 <errno.h> -#include <fcntl.h> -#include <sys/stat.h> -#include <sys/statfs.h> -#include <sys/types.h> -#include <unistd.h> - -#include <string> -#include <vector> - -#include "gmock/gmock.h" -#include "gtest/gtest.h" -#include "absl/strings/match.h" -#include "absl/strings/str_cat.h" -#include "absl/strings/string_view.h" -#include "test/syscalls/linux/file_base.h" -#include "test/util/cleanup.h" -#include "test/util/file_descriptor.h" -#include "test/util/fs_util.h" -#include "test/util/temp_path.h" -#include "test/util/test_util.h" - -#ifndef AT_STATX_FORCE_SYNC -#define AT_STATX_FORCE_SYNC 0x2000 -#endif -#ifndef AT_STATX_DONT_SYNC -#define AT_STATX_DONT_SYNC 0x4000 -#endif - -namespace gvisor { -namespace testing { - -namespace { - -class StatTest : public FileTest {}; - -TEST_F(StatTest, FstatatAbs) { - struct stat st; - - // Check that the stat works. - EXPECT_THAT(fstatat(AT_FDCWD, test_file_name_.c_str(), &st, 0), - SyscallSucceeds()); - EXPECT_TRUE(S_ISREG(st.st_mode)); -} - -TEST_F(StatTest, FstatatEmptyPath) { - struct stat st; - const auto fd = ASSERT_NO_ERRNO_AND_VALUE(Open(test_file_name_, O_RDONLY)); - - // Check that the stat works. - EXPECT_THAT(fstatat(fd.get(), "", &st, AT_EMPTY_PATH), SyscallSucceeds()); - EXPECT_TRUE(S_ISREG(st.st_mode)); -} - -TEST_F(StatTest, FstatatRel) { - struct stat st; - int dirfd; - auto filename = std::string(Basename(test_file_name_)); - - // Open the temporary directory read-only. - ASSERT_THAT(dirfd = open(GetAbsoluteTestTmpdir().c_str(), O_RDONLY), - SyscallSucceeds()); - - // Check that the stat works. - EXPECT_THAT(fstatat(dirfd, filename.c_str(), &st, 0), SyscallSucceeds()); - EXPECT_TRUE(S_ISREG(st.st_mode)); - close(dirfd); -} - -TEST_F(StatTest, FstatatSymlink) { - struct stat st; - - // Check that the link is followed. - EXPECT_THAT(fstatat(AT_FDCWD, "/proc/self", &st, 0), SyscallSucceeds()); - EXPECT_TRUE(S_ISDIR(st.st_mode)); - EXPECT_FALSE(S_ISLNK(st.st_mode)); - - // Check that the flag works. - EXPECT_THAT(fstatat(AT_FDCWD, "/proc/self", &st, AT_SYMLINK_NOFOLLOW), - SyscallSucceeds()); - EXPECT_TRUE(S_ISLNK(st.st_mode)); - EXPECT_FALSE(S_ISDIR(st.st_mode)); -} - -TEST_F(StatTest, Nlinks) { - // Skip this test if we are testing overlayfs because overlayfs does not - // (intentionally) return the correct nlink value for directories. - // See fs/overlayfs/inode.c:ovl_getattr(). - SKIP_IF(ASSERT_NO_ERRNO_AND_VALUE(IsOverlayfs(GetAbsoluteTestTmpdir()))); - - TempPath basedir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); - - // Directory is initially empty, it should contain 2 links (one from itself, - // one from "."). - EXPECT_THAT(Links(basedir.path()), IsPosixErrorOkAndHolds(2)); - - // Create a file in the test directory. Files shouldn't increase the link - // count on the base directory. - TempPath file1 = - ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileIn(basedir.path())); - EXPECT_THAT(Links(basedir.path()), IsPosixErrorOkAndHolds(2)); - - // Create subdirectories. This should increase the link count by 1 per - // subdirectory. - TempPath dir1 = - ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDirIn(basedir.path())); - EXPECT_THAT(Links(basedir.path()), IsPosixErrorOkAndHolds(3)); - TempPath dir2 = - ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDirIn(basedir.path())); - EXPECT_THAT(Links(basedir.path()), IsPosixErrorOkAndHolds(4)); - - // Removing directories should reduce the link count. - dir1.reset(); - EXPECT_THAT(Links(basedir.path()), IsPosixErrorOkAndHolds(3)); - dir2.reset(); - EXPECT_THAT(Links(basedir.path()), IsPosixErrorOkAndHolds(2)); - - // Removing files should have no effect on link count. - file1.reset(); - EXPECT_THAT(Links(basedir.path()), IsPosixErrorOkAndHolds(2)); -} - -TEST_F(StatTest, BlocksIncreaseOnWrite) { - struct stat st; - - // Stat the empty file. - ASSERT_THAT(fstat(test_file_fd_.get(), &st), SyscallSucceeds()); - - const int initial_blocks = st.st_blocks; - - // Write to the file, making sure to exceed the block size. - std::vector<char> buf(2 * st.st_blksize, 'a'); - ASSERT_THAT(write(test_file_fd_.get(), buf.data(), buf.size()), - SyscallSucceedsWithValue(buf.size())); - - // Stat the file again, and verify that number of allocated blocks has - // increased. - ASSERT_THAT(fstat(test_file_fd_.get(), &st), SyscallSucceeds()); - EXPECT_GT(st.st_blocks, initial_blocks); -} - -TEST_F(StatTest, PathNotCleaned) { - TempPath basedir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); - - // Create a file in the basedir. - TempPath file = - ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileIn(basedir.path())); - - // Stating the file directly should succeed. - struct stat buf; - EXPECT_THAT(lstat(file.path().c_str(), &buf), SyscallSucceeds()); - - // Try to stat the file using a directory that does not exist followed by - // "..". If the path is cleaned prior to stating (which it should not be) - // then this will succeed. - const std::string bad_path = JoinPath("/does_not_exist/..", file.path()); - EXPECT_THAT(lstat(bad_path.c_str(), &buf), SyscallFailsWithErrno(ENOENT)); -} - -TEST_F(StatTest, PathCanContainDotDot) { - TempPath basedir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); - TempPath subdir = - ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDirIn(basedir.path())); - const std::string subdir_name = std::string(Basename(subdir.path())); - - // Create a file in the subdir. - TempPath file = - ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileIn(subdir.path())); - const std::string file_name = std::string(Basename(file.path())); - - // Stat the file through a path that includes '..' and '.' but still resolves - // to the file. - const std::string good_path = - JoinPath(basedir.path(), subdir_name, "..", subdir_name, ".", file_name); - struct stat buf; - EXPECT_THAT(lstat(good_path.c_str(), &buf), SyscallSucceeds()); -} - -TEST_F(StatTest, PathCanContainEmptyComponent) { - TempPath basedir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); - - // Create a file in the basedir. - TempPath file = - ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileIn(basedir.path())); - const std::string file_name = std::string(Basename(file.path())); - - // Stat the file through a path that includes an empty component. We have to - // build this ourselves because JoinPath automatically removes empty - // components. - const std::string good_path = absl::StrCat(basedir.path(), "//", file_name); - struct stat buf; - EXPECT_THAT(lstat(good_path.c_str(), &buf), SyscallSucceeds()); -} - -TEST_F(StatTest, TrailingSlashNotCleanedReturnsENOTDIR) { - TempPath basedir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); - - // Create a file in the basedir. - TempPath file = - ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileIn(basedir.path())); - - // Stat the file with an extra "/" on the end of it. Since file is not a - // directory, this should return ENOTDIR. - const std::string bad_path = absl::StrCat(file.path(), "/"); - struct stat buf; - EXPECT_THAT(lstat(bad_path.c_str(), &buf), SyscallFailsWithErrno(ENOTDIR)); -} - -// Test fstatating a symlink directory. -TEST_F(StatTest, FstatatSymlinkDir) { - // Create a directory and symlink to it. - const auto dir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); - - const std::string symlink_to_dir = NewTempAbsPath(); - EXPECT_THAT(symlink(dir.path().c_str(), symlink_to_dir.c_str()), - SyscallSucceeds()); - auto cleanup = Cleanup([&symlink_to_dir]() { - EXPECT_THAT(unlink(symlink_to_dir.c_str()), SyscallSucceeds()); - }); - - // Fstatat the link with AT_SYMLINK_NOFOLLOW should return symlink data. - struct stat st = {}; - EXPECT_THAT( - fstatat(AT_FDCWD, symlink_to_dir.c_str(), &st, AT_SYMLINK_NOFOLLOW), - SyscallSucceeds()); - EXPECT_FALSE(S_ISDIR(st.st_mode)); - EXPECT_TRUE(S_ISLNK(st.st_mode)); - - // Fstatat the link should return dir data. - EXPECT_THAT(fstatat(AT_FDCWD, symlink_to_dir.c_str(), &st, 0), - SyscallSucceeds()); - EXPECT_TRUE(S_ISDIR(st.st_mode)); - EXPECT_FALSE(S_ISLNK(st.st_mode)); -} - -// Test fstatating a symlink directory with trailing slash. -TEST_F(StatTest, FstatatSymlinkDirWithTrailingSlash) { - // Create a directory and symlink to it. - const auto dir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); - const std::string symlink_to_dir = NewTempAbsPath(); - EXPECT_THAT(symlink(dir.path().c_str(), symlink_to_dir.c_str()), - SyscallSucceeds()); - auto cleanup = Cleanup([&symlink_to_dir]() { - EXPECT_THAT(unlink(symlink_to_dir.c_str()), SyscallSucceeds()); - }); - - // Fstatat on the symlink with a trailing slash should return the directory - // data. - struct stat st = {}; - EXPECT_THAT( - fstatat(AT_FDCWD, absl::StrCat(symlink_to_dir, "/").c_str(), &st, 0), - SyscallSucceeds()); - EXPECT_TRUE(S_ISDIR(st.st_mode)); - EXPECT_FALSE(S_ISLNK(st.st_mode)); - - // Fstatat on the symlink with a trailing slash with AT_SYMLINK_NOFOLLOW - // should return the directory data. - // Symlink to directory with trailing slash will ignore AT_SYMLINK_NOFOLLOW. - EXPECT_THAT(fstatat(AT_FDCWD, absl::StrCat(symlink_to_dir, "/").c_str(), &st, - AT_SYMLINK_NOFOLLOW), - SyscallSucceeds()); - EXPECT_TRUE(S_ISDIR(st.st_mode)); - EXPECT_FALSE(S_ISLNK(st.st_mode)); -} - -// Test fstatating a symlink directory with a trailing slash -// should return same stat data with fstatating directory. -TEST_F(StatTest, FstatatSymlinkDirWithTrailingSlashSameInode) { - // Create a directory and symlink to it. - const auto dir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); - - // We are going to assert that the symlink inode id is the same as the linked - // dir's inode id. In order for the inode id to be stable across - // save/restore, it must be kept open. The FileDescriptor type will do that - // for us automatically. - auto fd = ASSERT_NO_ERRNO_AND_VALUE(Open(dir.path(), O_RDONLY | O_DIRECTORY)); - - const std::string symlink_to_dir = NewTempAbsPath(); - EXPECT_THAT(symlink(dir.path().c_str(), symlink_to_dir.c_str()), - SyscallSucceeds()); - auto cleanup = Cleanup([&symlink_to_dir]() { - EXPECT_THAT(unlink(symlink_to_dir.c_str()), SyscallSucceeds()); - }); - - // Fstatat on the symlink with a trailing slash should return the directory - // data. - struct stat st = {}; - EXPECT_THAT(fstatat(AT_FDCWD, absl::StrCat(symlink_to_dir, "/").c_str(), &st, - AT_SYMLINK_NOFOLLOW), - SyscallSucceeds()); - EXPECT_TRUE(S_ISDIR(st.st_mode)); - - // Dir and symlink should point to same inode. - struct stat st_dir = {}; - EXPECT_THAT( - fstatat(AT_FDCWD, dir.path().c_str(), &st_dir, AT_SYMLINK_NOFOLLOW), - SyscallSucceeds()); - EXPECT_EQ(st.st_ino, st_dir.st_ino); -} - -TEST_F(StatTest, LeadingDoubleSlash) { - // Create a file, and make sure we can stat it. - TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); - struct stat st; - ASSERT_THAT(lstat(file.path().c_str(), &st), SyscallSucceeds()); - - // Now add an extra leading slash. - const std::string double_slash_path = absl::StrCat("/", file.path()); - ASSERT_TRUE(absl::StartsWith(double_slash_path, "//")); - - // We should be able to stat the new path, and it should resolve to the same - // file (same device and inode). - struct stat double_slash_st; - ASSERT_THAT(lstat(double_slash_path.c_str(), &double_slash_st), - SyscallSucceeds()); - EXPECT_EQ(st.st_dev, double_slash_st.st_dev); - EXPECT_EQ(st.st_ino, double_slash_st.st_ino); -} - -// Test that a rename doesn't change the underlying file. -TEST_F(StatTest, StatDoesntChangeAfterRename) { - const TempPath old_dir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); - const TempPath new_path(NewTempAbsPath()); - - struct stat st_old = {}; - struct stat st_new = {}; - - ASSERT_THAT(stat(old_dir.path().c_str(), &st_old), SyscallSucceeds()); - ASSERT_THAT(rename(old_dir.path().c_str(), new_path.path().c_str()), - SyscallSucceeds()); - ASSERT_THAT(stat(new_path.path().c_str(), &st_new), SyscallSucceeds()); - - EXPECT_EQ(st_old.st_nlink, st_new.st_nlink); - EXPECT_EQ(st_old.st_dev, st_new.st_dev); - EXPECT_EQ(st_old.st_ino, st_new.st_ino); - EXPECT_EQ(st_old.st_mode, st_new.st_mode); - EXPECT_EQ(st_old.st_uid, st_new.st_uid); - EXPECT_EQ(st_old.st_gid, st_new.st_gid); - EXPECT_EQ(st_old.st_size, st_new.st_size); -} - -// Test link counts with a regular file as the child. -TEST_F(StatTest, LinkCountsWithRegularFileChild) { - const TempPath dir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); - - struct stat st_parent_before = {}; - ASSERT_THAT(stat(dir.path().c_str(), &st_parent_before), SyscallSucceeds()); - EXPECT_EQ(st_parent_before.st_nlink, 2); - - // Adding a regular file doesn't adjust the parent's link count. - const TempPath child = - ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileIn(dir.path())); - - struct stat st_parent_after = {}; - ASSERT_THAT(stat(dir.path().c_str(), &st_parent_after), SyscallSucceeds()); - EXPECT_EQ(st_parent_after.st_nlink, 2); - - // The child should have a single link from the parent. - struct stat st_child = {}; - ASSERT_THAT(stat(child.path().c_str(), &st_child), SyscallSucceeds()); - EXPECT_TRUE(S_ISREG(st_child.st_mode)); - EXPECT_EQ(st_child.st_nlink, 1); - - // Finally unlinking the child should not affect the parent's link count. - ASSERT_THAT(unlink(child.path().c_str()), SyscallSucceeds()); - ASSERT_THAT(stat(dir.path().c_str(), &st_parent_after), SyscallSucceeds()); - EXPECT_EQ(st_parent_after.st_nlink, 2); -} - -// This test verifies that inodes remain around when there is an open fd -// after link count hits 0. -TEST_F(StatTest, ZeroLinksOpenFdRegularFileChild_NoRandomSave) { - // Setting the enviornment variable GVISOR_GOFER_UNCACHED to any value - // will prevent this test from running, see the tmpfs lifecycle. - // - // We need to support this because when a file is unlinked and we forward - // the stat to the gofer it would return ENOENT. - const char* uncached_gofer = getenv("GVISOR_GOFER_UNCACHED"); - SKIP_IF(uncached_gofer != nullptr); - - // We don't support saving unlinked files. - const DisableSave ds; - - const TempPath dir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); - const TempPath child = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileWith( - dir.path(), "hello", TempPath::kDefaultFileMode)); - - // The child should have a single link from the parent. - struct stat st_child_before = {}; - ASSERT_THAT(stat(child.path().c_str(), &st_child_before), SyscallSucceeds()); - EXPECT_TRUE(S_ISREG(st_child_before.st_mode)); - EXPECT_EQ(st_child_before.st_nlink, 1); - EXPECT_EQ(st_child_before.st_size, 5); // Hello is 5 bytes. - - // Open the file so we can fstat after unlinking. - const FileDescriptor fd = - ASSERT_NO_ERRNO_AND_VALUE(Open(child.path(), O_RDONLY)); - - // Now a stat should return ENOENT but we should still be able to stat - // via the open fd and fstat. - ASSERT_THAT(unlink(child.path().c_str()), SyscallSucceeds()); - - // Since the file has no more links stat should fail. - struct stat st_child_after = {}; - ASSERT_THAT(stat(child.path().c_str(), &st_child_after), - SyscallFailsWithErrno(ENOENT)); - - // Fstat should still allow us to access the same file via the fd. - struct stat st_child_fd = {}; - ASSERT_THAT(fstat(fd.get(), &st_child_fd), SyscallSucceeds()); - EXPECT_EQ(st_child_before.st_dev, st_child_fd.st_dev); - EXPECT_EQ(st_child_before.st_ino, st_child_fd.st_ino); - EXPECT_EQ(st_child_before.st_mode, st_child_fd.st_mode); - EXPECT_EQ(st_child_before.st_uid, st_child_fd.st_uid); - EXPECT_EQ(st_child_before.st_gid, st_child_fd.st_gid); - EXPECT_EQ(st_child_before.st_size, st_child_fd.st_size); - - // TODO(b/34861058): This isn't ideal but since fstatfs(2) will always return - // OVERLAYFS_SUPER_MAGIC we have no way to know if this fs is backed by a - // gofer which doesn't support links. - EXPECT_TRUE(st_child_fd.st_nlink == 0 || st_child_fd.st_nlink == 1); -} - -// Test link counts with a directory as the child. -TEST_F(StatTest, LinkCountsWithDirChild) { - // Skip this test if we are testing overlayfs because overlayfs does not - // (intentionally) return the correct nlink value for directories. - // See fs/overlayfs/inode.c:ovl_getattr(). - SKIP_IF(ASSERT_NO_ERRNO_AND_VALUE(IsOverlayfs(GetAbsoluteTestTmpdir()))); - - const TempPath dir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); - - // Before a child is added the two links are "." and the link from the parent. - struct stat st_parent_before = {}; - ASSERT_THAT(stat(dir.path().c_str(), &st_parent_before), SyscallSucceeds()); - EXPECT_EQ(st_parent_before.st_nlink, 2); - - // Create a subdirectory and stat for the parent link counts. - const TempPath sub_dir = - ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDirIn(dir.path())); - - // The three links are ".", the link from the parent, and the link from - // the child as "..". - struct stat st_parent_after = {}; - ASSERT_THAT(stat(dir.path().c_str(), &st_parent_after), SyscallSucceeds()); - EXPECT_EQ(st_parent_after.st_nlink, 3); - - // The child will have 1 link from the parent and 1 link which represents ".". - struct stat st_child = {}; - ASSERT_THAT(stat(sub_dir.path().c_str(), &st_child), SyscallSucceeds()); - EXPECT_TRUE(S_ISDIR(st_child.st_mode)); - EXPECT_EQ(st_child.st_nlink, 2); - - // Finally delete the child dir and the parent link count should return to 2. - ASSERT_THAT(rmdir(sub_dir.path().c_str()), SyscallSucceeds()); - ASSERT_THAT(stat(dir.path().c_str(), &st_parent_after), SyscallSucceeds()); - - // Now we should only have links from the parent and "." since the subdir - // has been removed. - EXPECT_EQ(st_parent_after.st_nlink, 2); -} - -// Test statting a child of a non-directory. -TEST_F(StatTest, ChildOfNonDir) { - // Create a path that has a child of a regular file. - const std::string filename = JoinPath(test_file_name_, "child"); - - // Statting the path should return ENOTDIR. - struct stat st; - EXPECT_THAT(lstat(filename.c_str(), &st), SyscallFailsWithErrno(ENOTDIR)); -} - -// Test lstating a symlink directory. -TEST_F(StatTest, LstatSymlinkDir) { - // Create a directory and symlink to it. - const auto dir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); - const std::string symlink_to_dir = NewTempAbsPath(); - EXPECT_THAT(symlink(dir.path().c_str(), symlink_to_dir.c_str()), - SyscallSucceeds()); - auto cleanup = Cleanup([&symlink_to_dir]() { - EXPECT_THAT(unlink(symlink_to_dir.c_str()), SyscallSucceeds()); - }); - - // Lstat on the symlink should return symlink data. - struct stat st = {}; - ASSERT_THAT(lstat(symlink_to_dir.c_str(), &st), SyscallSucceeds()); - EXPECT_FALSE(S_ISDIR(st.st_mode)); - EXPECT_TRUE(S_ISLNK(st.st_mode)); - - // Lstat on the symlink with a trailing slash should return the directory - // data. - ASSERT_THAT(lstat(absl::StrCat(symlink_to_dir, "/").c_str(), &st), - SyscallSucceeds()); - EXPECT_TRUE(S_ISDIR(st.st_mode)); - EXPECT_FALSE(S_ISLNK(st.st_mode)); -} - -// Verify that we get an ELOOP from too many symbolic links even when there -// are directories in the middle. -TEST_F(StatTest, LstatELOOPPath) { - const TempPath dir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); - std::string subdir_base = "subdir"; - ASSERT_THAT(mkdir(JoinPath(dir.path(), subdir_base).c_str(), 0755), - SyscallSucceeds()); - - std::string target = JoinPath(dir.path(), subdir_base, subdir_base); - std::string dst = JoinPath("..", subdir_base); - ASSERT_THAT(symlink(dst.c_str(), target.c_str()), SyscallSucceeds()); - auto cleanup = Cleanup( - [&target]() { EXPECT_THAT(unlink(target.c_str()), SyscallSucceeds()); }); - - // Now build a path which is /subdir/subdir/... repeated many times so that - // we can build a path that is shorter than PATH_MAX but can still cause - // too many symbolic links. Note: Every other subdir is actually a directory - // so we're not in a situation where it's a -> b -> a -> b, where a and b - // are symbolic links. - std::string path = dir.path(); - std::string subdir_append = absl::StrCat("/", subdir_base); - do { - absl::StrAppend(&path, subdir_append); - // Keep appending /subdir until we would overflow PATH_MAX. - } while ((path.size() + subdir_append.size()) < PATH_MAX); - - struct stat s = {}; - ASSERT_THAT(lstat(path.c_str(), &s), SyscallFailsWithErrno(ELOOP)); -} - -// Ensure that inode allocation for anonymous devices work correctly across -// save/restore. In particular, inode numbers should be unique across S/R. -TEST(SimpleStatTest, AnonDeviceAllocatesUniqueInodesAcrossSaveRestore) { - // Use sockets as a convenient way to create inodes on an anonymous device. - int fd; - ASSERT_THAT(fd = socket(AF_UNIX, SOCK_STREAM, 0), SyscallSucceeds()); - FileDescriptor fd1(fd); - MaybeSave(); - ASSERT_THAT(fd = socket(AF_UNIX, SOCK_STREAM, 0), SyscallSucceeds()); - FileDescriptor fd2(fd); - - struct stat st1; - struct stat st2; - ASSERT_THAT(fstat(fd1.get(), &st1), SyscallSucceeds()); - ASSERT_THAT(fstat(fd2.get(), &st2), SyscallSucceeds()); - - // The two fds should have different inode numbers. - EXPECT_NE(st2.st_ino, st1.st_ino); - - // Verify again after another S/R cycle. The inode numbers should remain the - // same. - MaybeSave(); - - struct stat st1_after; - struct stat st2_after; - ASSERT_THAT(fstat(fd1.get(), &st1_after), SyscallSucceeds()); - ASSERT_THAT(fstat(fd2.get(), &st2_after), SyscallSucceeds()); - - EXPECT_EQ(st1_after.st_ino, st1.st_ino); - EXPECT_EQ(st2_after.st_ino, st2.st_ino); -} - -#ifndef SYS_statx -#if defined(__x86_64__) -#define SYS_statx 332 -#elif defined(__aarch64__) -#define SYS_statx 291 -#else -#error "Unknown architecture" -#endif -#endif // SYS_statx - -#ifndef STATX_ALL -#define STATX_ALL 0x00000fffU -#endif // STATX_ALL - -// struct kernel_statx_timestamp is a Linux statx_timestamp struct. -struct kernel_statx_timestamp { - int64_t tv_sec; - uint32_t tv_nsec; - int32_t __reserved; -}; - -// struct kernel_statx is a Linux statx struct. Old versions of glibc do not -// expose it. See include/uapi/linux/stat.h -struct kernel_statx { - uint32_t stx_mask; - uint32_t stx_blksize; - uint64_t stx_attributes; - uint32_t stx_nlink; - uint32_t stx_uid; - uint32_t stx_gid; - uint16_t stx_mode; - uint16_t __spare0[1]; - uint64_t stx_ino; - uint64_t stx_size; - uint64_t stx_blocks; - uint64_t stx_attributes_mask; - struct kernel_statx_timestamp stx_atime; - struct kernel_statx_timestamp stx_btime; - struct kernel_statx_timestamp stx_ctime; - struct kernel_statx_timestamp stx_mtime; - uint32_t stx_rdev_major; - uint32_t stx_rdev_minor; - uint32_t stx_dev_major; - uint32_t stx_dev_minor; - uint64_t __spare2[14]; -}; - -int statx(int dirfd, const char* pathname, int flags, unsigned int mask, - struct kernel_statx* statxbuf) { - return syscall(SYS_statx, dirfd, pathname, flags, mask, statxbuf); -} - -TEST_F(StatTest, StatxAbsPath) { - SKIP_IF(!IsRunningOnGvisor() && statx(-1, nullptr, 0, 0, nullptr) < 0 && - errno == ENOSYS); - - struct kernel_statx stx; - EXPECT_THAT(statx(-1, test_file_name_.c_str(), 0, STATX_ALL, &stx), - SyscallSucceeds()); - EXPECT_TRUE(S_ISREG(stx.stx_mode)); -} - -TEST_F(StatTest, StatxRelPathDirFD) { - SKIP_IF(!IsRunningOnGvisor() && statx(-1, nullptr, 0, 0, nullptr) < 0 && - errno == ENOSYS); - - struct kernel_statx stx; - auto const dirfd = - ASSERT_NO_ERRNO_AND_VALUE(Open(GetAbsoluteTestTmpdir(), O_RDONLY)); - auto filename = std::string(Basename(test_file_name_)); - - EXPECT_THAT(statx(dirfd.get(), filename.c_str(), 0, STATX_ALL, &stx), - SyscallSucceeds()); - EXPECT_TRUE(S_ISREG(stx.stx_mode)); -} - -TEST_F(StatTest, StatxRelPathCwd) { - SKIP_IF(!IsRunningOnGvisor() && statx(-1, nullptr, 0, 0, nullptr) < 0 && - errno == ENOSYS); - - ASSERT_THAT(chdir(GetAbsoluteTestTmpdir().c_str()), SyscallSucceeds()); - auto filename = std::string(Basename(test_file_name_)); - struct kernel_statx stx; - EXPECT_THAT(statx(AT_FDCWD, filename.c_str(), 0, STATX_ALL, &stx), - SyscallSucceeds()); - EXPECT_TRUE(S_ISREG(stx.stx_mode)); -} - -TEST_F(StatTest, StatxEmptyPath) { - SKIP_IF(!IsRunningOnGvisor() && statx(-1, nullptr, 0, 0, nullptr) < 0 && - errno == ENOSYS); - - const auto fd = ASSERT_NO_ERRNO_AND_VALUE(Open(test_file_name_, O_RDONLY)); - struct kernel_statx stx; - EXPECT_THAT(statx(fd.get(), "", AT_EMPTY_PATH, STATX_ALL, &stx), - SyscallSucceeds()); - EXPECT_TRUE(S_ISREG(stx.stx_mode)); -} - -TEST_F(StatTest, StatxDoesNotRejectExtraneousMaskBits) { - SKIP_IF(!IsRunningOnGvisor() && statx(-1, nullptr, 0, 0, nullptr) < 0 && - errno == ENOSYS); - - struct kernel_statx stx; - // Set all mask bits except for STATX__RESERVED. - uint mask = 0xffffffff & ~0x80000000; - EXPECT_THAT(statx(-1, test_file_name_.c_str(), 0, mask, &stx), - SyscallSucceeds()); - EXPECT_TRUE(S_ISREG(stx.stx_mode)); -} - -TEST_F(StatTest, StatxRejectsReservedMaskBit) { - SKIP_IF(!IsRunningOnGvisor() && statx(-1, nullptr, 0, 0, nullptr) < 0 && - errno == ENOSYS); - - struct kernel_statx stx; - // Set STATX__RESERVED in the mask. - EXPECT_THAT(statx(-1, test_file_name_.c_str(), 0, 0x80000000, &stx), - SyscallFailsWithErrno(EINVAL)); -} - -TEST_F(StatTest, StatxSymlink) { - SKIP_IF(!IsRunningOnGvisor() && statx(-1, nullptr, 0, 0, nullptr) < 0 && - errno == ENOSYS); - - std::string parent_dir = "/tmp"; - TempPath link = ASSERT_NO_ERRNO_AND_VALUE( - TempPath::CreateSymlinkTo(parent_dir, test_file_name_)); - std::string p = link.path(); - - struct kernel_statx stx; - EXPECT_THAT(statx(AT_FDCWD, p.c_str(), AT_SYMLINK_NOFOLLOW, STATX_ALL, &stx), - SyscallSucceeds()); - EXPECT_TRUE(S_ISLNK(stx.stx_mode)); - EXPECT_THAT(statx(AT_FDCWD, p.c_str(), 0, STATX_ALL, &stx), - SyscallSucceeds()); - EXPECT_TRUE(S_ISREG(stx.stx_mode)); -} - -TEST_F(StatTest, StatxInvalidFlags) { - SKIP_IF(!IsRunningOnGvisor() && statx(-1, nullptr, 0, 0, nullptr) < 0 && - errno == ENOSYS); - - struct kernel_statx stx; - EXPECT_THAT(statx(AT_FDCWD, test_file_name_.c_str(), 12345, 0, &stx), - SyscallFailsWithErrno(EINVAL)); - - // Sync flags are mutually exclusive. - EXPECT_THAT(statx(AT_FDCWD, test_file_name_.c_str(), - AT_STATX_FORCE_SYNC | AT_STATX_DONT_SYNC, 0, &stx), - SyscallFailsWithErrno(EINVAL)); -} - -} // namespace - -} // namespace testing -} // namespace gvisor |