The kernel will reply with -ENOTDIR when we try to access a non-directory under
a name which ends with a slash. But our functions would strip the trailing slash
under various circumstances. Keep the trailing slash, so that
path_is_mount_point("/path/to/file/") return -ENOTDIR when /path/to/file/ is a file.
Tests are added for this change in behaviour.
Also, when called with a trailing slash, path_is_mount_point() would get
"" from basename(), and call name_to_handle_at(3, "", ...), and always
return -ENOENT. Now it'll return -ENOTDIR if the mount point is a file, and
true if it is a directory and a mount point.
v2:
- use strip_trailing_chars()
v3:
- instead of stripping trailing chars(), do the opposite — preserve them.
Don't miscount number of "../" to generate, if we "." is included in an
input path.
Also, refuse if we encounter "../" since we can't possibly follow that
up properly, without file system access.
Some other modernizations.
This new helper removes a leading /dev if there is one. We have code
doing this all over the place, let's unify this, and correct it while
we are at it, by using path_startswith() rather than startswith() to
drop the prefix.
This filters out "." and ".." from glob results. Fixes#5655 and #5644.
Any judgements on whether the path is "safe" are removed. We will not remove
"/" under any name (including "/../" and such), but we will remove stuff that
is specified using paths that include "//", "/./" and "/../". Such paths can be
created when joining strings automatically, or for other reasons, and people
generally know what ".." and "." is.
Tests are added to make sure that the helper functions behave as expected.
Let's use chase_symlinks() everywhere, and stop using GNU
canonicalize_file_name() everywhere. For most cases this should not change
behaviour, however increase exposure of our function to get better tested. Most
importantly in a few cases (most notably nspawn) it can take the correct root
directory into account when chasing symlinks.
Depending on how binutils was configured and the --enable-fast-install
configure option, the test binary might be called either name.
Fixes: https://github.com/systemd/systemd/issues/3838
Link as many binaries as possible with it, to save storage space.
Preserve the static libshared and libbasic for use in libraries, nss
modules and udev.
Libraries need to be static in order to avoid polluting the symbol
namespace.
Udev needs to be static so downstream can avoid strict version dependencies
with the systemd package, and this can complicate upgrade scenarios.
There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
Modernize the code a bit:
- Get rid of FOREACH_WORD_SEPARATOR() loop in favour of a
extract_first_word() loop.
- Remove find_binary()'s "local" flag. It's not reasonably possible to
look for binaries on remote systems, we hence should not pretend we
could.
- When we cannot find a suitable binary, return the last error returned
from access() rather than ENOENT unconditionally.
- Rework fsck_exists() and mkfs_exists() to return 1 on success, 0 if
the implementation is missing and negative on real errors. This is
more like we do it in other functions.
- Make sure we also detect direct fsck symlinks to "true", rather than
just absolute ones to /bin/true.
When we have a structure like this:
/bin -> /usr/bin
/usr is a mount point
Then path_is_mount_point("/bin", AT_SYMLINK_FOLLOW) needs to look at the pair
/usr/bin and /usr, not at the pair / and /usr/bin, as the latter have different
mount IDs. But we only want to consider the base name, not any parent.
Thus we have to resolve the given path first to get the real parent when
allowing symlinks.
Bug: https://github.com/systemd/systemd/issues/61
Commits 27cc6f166 and f25afeb broke path_is_mount_point() for files (such as
/etc/machine-id → /run/machine-id bind mounts) as with the factorization of
fd_is_mount_point() we lost the parent directory. We cannot determine that from
an fd only as openat(fd, "..") only works for directory fds.
Change fd_is_mount_point() to behave like openat(): It now takes a file
descriptor of the containing directory, a file name in it, and flags (which can
be 0 or AT_SYMLINK_FOLLOW). Unlike name_to_handle_at() or openat(), fstatat()
only accepts the inverse flag AT_SYMLINK_NOFOLLOW and complains with EINVAL
about AT_SYMLINK_FOLLOW; so we need to transform the flags for that fallback.
Adjust rm_rf_children() accordingly (only other caller of fd_is_mount_point()
aside from path_is_mount_point()).
Add test cases for files, links, and file bind mounts (the latter will only
work when running as root). Split out a new test_path_is_mount_point() test
case function as it got significantly larger now.
So far a number of utilities implemented their own calls for this, unify
them in prefix_root() and prefix_roota(). The former uses heap memory,
the latter allocates from the stack via alloca().
Port over most users of a --root= logic.
systemd-run would fail when run with -M or -H and an absolute path,
if this path did not exists locally. Allow it to continue, since we
don't have a nice way of checking if the binary exists remotely.
The case where -M or -H is used and a local path is unchanged, and we
still iterate over $PATH to find the binary. We need to convert to an
absolute path, and we don't have a nice mechanism to check remotely,
so we assume that the binary will be located in the same place locally
and remotely.
http://lists.freedesktop.org/archives/systemd-devel/2014-November/025418.html
Otherwise they get optimized out when CPPFLAGS='-DNDEBUG' is used, and that
causes the tests to fail.
Tested:
- make check TESTS='test-path-util' CPPFLAGS='-DNDEBUG'
In contrast to a filename-only argument, find_binary() did not
actually check if an path exists, allowing the code to fail later on.
This was OK, but it seems nicer to treat both paths identically.
Also take advantage of path_make_absolute_cwd doing strdup() by itself
if necessary to simplify.
The only problem is that libgen.h #defines basename to point to it's
own broken implementation instead of the GNU one. This can be fixed
by #undefining basename.
