Squashed commit of the following:
commit 04fff3a637d455cbb1d75937a235950e43008db9
Author: Eelco Dolstra <edolstra@gmail.com>
Date: Thu Jun 12 12:30:32 2025 +0200
Chown structured attr files safely
commit 5417ad445e414c649d0cfc71a05661c7bf8f3ef5
Author: Eelco Dolstra <edolstra@gmail.com>
Date: Thu Jun 12 12:14:04 2025 +0200
Replace 'bool sync' with an enum for clarity
And drop writeFileAndSync().
commit 7ae0141f328d8e8e1094be24665789c05f974ba6
Author: Eelco Dolstra <edolstra@gmail.com>
Date: Thu Jun 12 11:35:28 2025 +0200
Drop guessOrInventPathFromFD()
No need to do hacky stuff like that when we already know the original path.
commit 45b05098bd019da7c57cd4227a89bfd0fa65bb08
Author: Eelco Dolstra <edolstra@gmail.com>
Date: Thu Jun 12 11:15:58 2025 +0200
Tweak comment
commit 0af15b31209d1b7ec8addfae9a1a6b60d8f35848
Author: Raito Bezarius <raito@lix.systems>
Date: Thu Mar 27 12:22:26 2025 +0100
libstore: ensure that temporary directory is always 0o000 before deletion
In the case the deletion fails, we should ensure that the temporary
directory cannot be used for nefarious purposes.
Change-Id: I498a2dd0999a74195d13642f44a5de1e69d46120
Signed-off-by: Raito Bezarius <raito@lix.systems>
commit 2c20fa37b15cfa03ac6a1a6a47cdb2ed66c0827e
Author: Raito Bezarius <raito@lix.systems>
Date: Wed Mar 26 12:42:55 2025 +0100
libutil: ensure that `_deletePath` does NOT use absolute paths with dirfds
When calling `_deletePath` with a parent file descriptor, `openat` is
made effective by using relative paths to the directory file descriptor.
To avoid the problem, the signature is changed to resist misuse with an
assert in the prologue of the function.
Change-Id: I6b3fc766bad2afe54dc27d47d1df3873e188de96
Signed-off-by: Raito Bezarius <raito@lix.systems>
commit d3c370bbcae48bb825ce19fd0f73bb4eefd2c9ea
Author: Raito Bezarius <raito@lix.systems>
Date: Wed Mar 26 01:07:47 2025 +0100
libstore: ensure that `passAsFile` is created in the original temp dir
This ensures that `passAsFile` data is created inside the expected
temporary build directory by `openat()` from the parent directory file
descriptor.
This avoids a TOCTOU which is part of the attack chain of CVE-????.
Change-Id: Ie5273446c4a19403088d0389ae8e3f473af8879a
Signed-off-by: Raito Bezarius <raito@lix.systems>
commit 45d3598724f932d024ef6bc2ffb00c1bb90e6018
Author: Raito Bezarius <raito@lix.systems>
Date: Wed Mar 26 01:06:03 2025 +0100
libutil: writeFile variant for file descriptors
`writeFile` lose its `sync` boolean flag to make things simpler.
A new `writeFileAndSync` function is created and all call sites are
converted to it.
Change-Id: Ib871a5283a9c047db1e4fe48a241506e4aab9192
Signed-off-by: Raito Bezarius <raito@lix.systems>
commit 732bd9b98cabf4aaf95a01fd318923de303f9996
Author: Raito Bezarius <raito@lix.systems>
Date: Wed Mar 26 01:05:34 2025 +0100
libstore: chown to builder variant for file descriptors
We use it immediately for the build temporary directory.
Change-Id: I180193c63a2b98721f5fb8e542c4e39c099bb947
Signed-off-by: Raito Bezarius <raito@lix.systems>
commit 962c65f8dcd5570dd92c72370a862c7b38942e0d
Author: Raito Bezarius <raito@lix.systems>
Date: Wed Mar 26 01:04:59 2025 +0100
libstore: open build directory as a dirfd as well
We now keep around a proper AutoCloseFD around the temporary directory
which we plan to use for openat operations and avoiding the build
directory being swapped out while we are doing something else.
Change-Id: I18d387b0f123ebf2d20c6405cd47ebadc5505f2a
Signed-off-by: Raito Bezarius <raito@lix.systems>
commit c9b42462b75b5a37ee6564c2b53cff186c8323da
Author: Raito Bezarius <raito@lix.systems>
Date: Wed Mar 26 01:04:12 2025 +0100
libutil: guess or invent a path from file descriptors
This is useful for certain error recovery paths (no pun intended) that
does not thread through the original path name.
Change-Id: I2d800740cb4f9912e64c923120d3f977c58ccb7e
Signed-off-by: Raito Bezarius <raito@lix.systems>
We're not replacing `Path` in exposed definitions in many cases, but
just adding alternatives. This will allow us to "top down" change `Path`
to `std::fileysystem::path`, and then we can remove the `Path`-using
utilities which will become unused.
Also add some test files which we forgot to include in the libutil unit
tests `meson.build`.
Co-Authored-By: siddhantCodes <siddhantk232@gmail.com>
This ended up motivating a good deal of other infra improvements in
order to get Windows right:
- `OsString` to complement `std::filesystem::path`
- env var code for working with the underlying `OsString`s
- Rename `PATHNG_LITERAL` to `OS_STR`
- `NativePathTrait` renamed to `OsPathTrait`, given a character template
parameter until #9205 is complete.
Split `tests.cc` matching split of `util.{cc,hh}` last year.
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Instead of running the builds under
`$TMPDIR/{unique-build-directory-owned-by-the-build-user}`, run them
under `$TMPDIR/{unique-build-directory-owned-by-the-daemon}/{subdir-owned-by-the-build-user}`
where the build directory is only readable and traversable by the daemon user.
This achieves two things:
1. It prevents builders from making their build directory world-readable
(or even writeable), which would allow the outside world to interact
with them.
2. It prevents external processes running as the build user (either
because that somehow leaked, maybe as a consequence of 1., or because
`build-users` isn't in use) from gaining access to the build
directory.
The implementation of `nix::createDirs` allows it to be a simple wrapper
around `std::filesystem::create_directories` as its return value is not
used anywhere.
the old `copyFile` was just a wrapper that was calling the `copy`
function. This wrapper function is removed and the `copy` function is
renamed to `copyFile`.
This makes for shorter and more portable code.
The only tricky part is catching exceptions: I just searched for near by
`catch (Error &)` or `catch (SysError &)` and adjusted them to `catch
(std::filesystem::filesystem_error &)` according to my human judgement.
Good for windows portability; will help @siddhantk232 with his GSOC
project.
At this point many features are stripped out, but this works:
- Can run libnix{util,store,expr} unit tests
- Can run some Nix commands
Co-Authored-By volth <volth@volth.com>
Co-Authored-By Brian McKenna <brian@brianmckenna.org>
This function is nice for more than `PosixSourceAccessor`. We can make a
few things simpler with it.
Note that the error logic slightly changes in some of the call sites, in
that we also count `ENOTDIR` and not just `ENOENT` as not having the
file, but that should be fine.
Fixes an instance of
nix: src/libutil/util.cc:139: nix::Path nix::canonPath(PathView, bool): Assertion `path != ""' failed.
... which I've been getting in one of my shells for some reason.
I have yet to find out why TMPDIR was empty, but it's no reason for
Nix to break.
It is possible to exfiltrate a file descriptor out of the build sandbox
of FODs, and use it to modify the store path after it has been
registered.
To avoid that issue, don't register the output of the build, but a copy
of it (that will be free of any leaked file descriptor).
All OS and IO operations should be moved out, leaving only some misc
portable pure functions.
This is useful to avoid copious CPP when doing things like Windows and
Emscripten ports.
Newly exposed functions to break cycles:
- `restoreSignals`
- `updateWindowSize`
