upcast_goal was only ever needed to break circular includes, but the
same solution that gave us upcast_goal also lets us fully remove it:
just upcast goals without a wrapper function, but only in .cc files.
Change-Id: I9c71654b2535121459ba7dcfd6c5da5606904032
the rewriting sink was just broken. when given a rewrite set that
contained a key that is also a proper infix of another key it was
possible to produce an incorrectly rewritten result if the writer
used the wrong block size. fixing this duplicates rewriteStrings,
to avoid this we'll rewrite rewriteStrings to use RewritingSource
in a new mode that'll allow rewrites we had previously forbidden.
Change-Id: I57fa0a9a994e654e11d07172b8e31d15f0b7e8c0
This rather simple function existed just to check some flags,
but the response varies by platform. This is a perfect case for
our subclasses.
Change-Id: Ieb1732a8d024019236e0d0028ad843a24ec3dc59
this much more closely mimics what is actually happening: we're reading
data from somewhere else, actively, rather than passively waiting. with
the data flow matching the underlying system interactions better we can
remove a few sinkToSource calls that merely exists to undo the mismatch
caused by not treating subprocess output as a data source to begin with
Change-Id: If4abfc2f8398fb5e88c9b91a8bdefd5504bb2d11
this will let us also return a source for the program output later,
which will in turn make sinkToSource unnecessary for program output
processing. this may also reopen a path for provigin program input,
but that still needs a proper async io framework to avoid problems.
Change-Id: Iaf93f47db99c38cfaf134bd60ed6a804d7ddf688
Add a platform-specific function for starting sandboxed child.
Generally this just means startProcess, but on Linux we use flags
for clone to start a new namespace
Change-Id: I41c8aba62676a162388bbe5ab8a7518904c7b058
Add a new OS-specific hook called `prepareSandbox`, run before forking
On Darwin this is empty as nothing is required,
on Linux this creates the chroot directory and adds basic files,
and on platforms using a fallback this throws an exception
Change-Id: Ie30c38c387f2e0e5844b2afa32fd4d33b1180dae
This is a shameless layering violation in favour of UX. It falls back
trivially to "unknown", so it's purely a UX feature.
Diagnostic sample:
```
error: hash mismatch in fixed-output derivation '/nix/store/sjfw324j4533lwnpmr5z4icpb85r63ai-x1.drv':
likely URL: https://meow.puppy.forge/puppy.tar.gz
specified: sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
got: sha256-a1Qvp3FOOkWpL9kFHgugU1ok5UtRPSu+NwCZKbbaEro=
```
Change-Id: I873eedcf7984ab23f57a6754be00232b5cb5b02c
This is a squash of upstream PRs #10303, #10312 and #10883.
fix: Treat empty TMPDIR as unset
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.
(cherry picked from commit c3fb2aa1f9d1fa756dac38d3588c836c5a5395dc)
fix: Treat empty XDG_RUNTIME_DIR as unset
See preceding commit. Not observed in the wild, but is sensible
and consistent with TMPDIR behavior.
(cherry picked from commit b9e7f5aa2df3f0e223f5c44b8089cbf9b81be691)
local-derivation-goal.cc: Reuse defaultTempDir()
(cherry picked from commit fd31945742710984de22805ee8d97fbd83c3f8eb)
fix: remove usage of XDG_RUNTIME_DIR for TMP
(cherry picked from commit 1363f51bcb24ab9948b7b5093490a009947f7453)
tests/functional: Add count()
(cherry picked from commit 6221770c9de4d28137206bdcd1a67eea12e1e499)
Remove uncalled for message
(cherry picked from commit b1fe388d33530f0157dcf9f461348b61eda13228)
Add build-dir setting
(cherry picked from commit 8b16cced18925aa612049d08d5e78eccbf0530e4)
Change-Id: Ic7b75ff0b6a3b19e50a4ac8ff2d70f15c683c16a
copy-constructing or assigning from pid_t can easily lead to duplicate
Pid instances for the same process if a pid_t was used carelessly, and
Pid itself was copy-constructible. both could cause surprising results
such as killing processes twice (which could become very problemantic,
but luckily modern systems don't reuse PIDs all that quickly), or more
than one piece of the code believing it owns a process when neither do
Change-Id: Ifea7445f84200b34c1a1d0acc2cdffe0f01e20c6
this is only used in one place, and only to set a nicer error message on
EndOfFile. the only caller that actually *catches* this exception should
provide an error message in that catch block rather than forcing support
for setting error message so deep into the stack. copyStorePath is never
called outside of PathSubstitutionGoal anyway, which catches everything.
Change-Id: Ifbae8706d781c388737706faf4c8a8b7917ca278
LocalDerivationGoal includes a large number of low-level sandboxing
primitives for Darwin and Linux, intermingled with ifdefs.
Start creating platform-specific classes to make it easier to add new
platforms and review platform-specific code.
This change only creates support infrastructure and moves two function,
more functions will be moved in future changes.
Change-Id: I9fc29fa2a7345107d4fc96c46fa90b4eabf6bb89
This comes quite often when the available job slots on all remote
builders are exhausted and this is pretty spammy.
This isn't really an issue, but expected behavior.
A better way to display this is a nom-like approach where all scheduled
builds are shown in a tree and pending builds are being marked as such
IMHO.
Change-Id: I6bc14e6054f84e3eb0768127b490e263d8cdcf89
don't consume a sink, return a source instead. the only reason to not do
this is a very slight reduction in dynamic allocations, but since we are
going to *at least* do disk io that will not be a lot of overhead anyway
Change-Id: Iae2f879ec64c3c3ac1d5310eeb6a85e696d4614a
This happened during a PathSubstitutionGoal of a .drv file:
substitution of '/tmp/jade/nix-test/ca/eval-store/store/1lj7lsq5y0f25mfbnq6d3zd0bw5ay33n-dependencies-input-2.drv'
What happened here is that since PathSubstitutionGoal is not a
DerivationGoal, in production builds, the UB was not caught, since it
would early-exit from failing a dynamic_cast to DerivationGoal * on the
very next line, but before the null reference was ever used.
This was nonetheless UB. The fix should be to just rearrange the two
lines; I don't think there is a further bug there, since *substituting a
.drv* **necessarily** means you cannot have the representation of
the derivation as would be necessary for drv to not be null there.
Test failure:
++(eval-store.sh:12) _RR_TRACE_DIR=/home/jade/.local/share/rr rr record -- nix build -f dependencies.nix --eval-store /tmp/jade/nix-test/ca/eval-store/eval-store -o /tmp/jade/nix-test/ca/eval-store/result
don't know how to build these paths:
/tmp/jade/nix-test/ca/eval-store/store/6y51mf0p57ggipgab6hdjabbvplzsicq-dependencies-top.drv
copying 1 paths...
copying path '/tmp/jade/nix-test/ca/eval-store/store/8027afyvqb87y1sf5xhdkqsflqn1ziy8-dependencies.builder0.sh' to 'local'...
copying 1 paths...
copying path '/tmp/jade/nix-test/ca/eval-store/store/7r5pqyncvfgrryf9gzy1z56z3xigi61x-builder-dependencies-input-0.sh' to 'local'...
copying 1 paths...
copying path '/tmp/jade/nix-test/ca/eval-store/store/nhmgm87zlqy3ks96dxrn7l37b72azi99-builder-dependencies-input-1.sh' to 'local'...
copying 1 paths...
copying path '/tmp/jade/nix-test/ca/eval-store/store/nq4qa2j6y8ajqazlfq6h46ck637my1n6-builder-dependencies-input-2.sh' to 'local'...
copying 1 paths...
copying path '/tmp/jade/nix-test/ca/eval-store/store/6vh0vna9l5afck01y7iaks3hm9ikwqyj-builder-fod-input.sh' to 'local'...
building '/tmp/jade/nix-test/ca/eval-store/store/gy91pqymf2nc5v7ld1bad94xpwxdi25s-dependencies-input-0.drv'...
building '/tmp/jade/nix-test/ca/eval-store/store/w7wlkjx97ivmnrymkac5av3nyp94hzvq-dependencies-input-1.drv'...
../src/libstore/build/derivation-goal.cc:1556:22: runtime error: reference binding to null pointer of type 'Derivation'
0 0x734ba59a6886 in nix::DerivationGoal::waiteeDone(std::shared_ptr<nix::Goal>, nix::Goal::ExitCode) /home/jade/lix/lix2/build/src/libstore/build/derivation-goal.cc:1556:12
1 0x734ba59c0962 in nix::Goal::amDone(nix::Goal::ExitCode, std::optional<nix::Error>) /home/jade/lix/lix2/build/src/libstore/build/goal.cc:95:25
2 0x734ba5a1c44a in nix::PathSubstitutionGoal::done(nix::Goal::ExitCode, nix::BuildResult::Status, std::optional<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>>) /home/jade/lix/lix2/build/src/libstore/build/substitution-goal.cc:38:5
3 0x734ba5a1b454 in nix::PathSubstitutionGoal::init() /home/jade/lix/lix2/build/src/libstore/build/substitution-goal.cc:56:9
4 0x734ba5a2a6c6 in nix::Worker::run(std::set<std::shared_ptr<nix::Goal>, nix::CompareGoalPtrs, std::allocator<std::shared_ptr<nix::Goal>>> const&) /home/jade/lix/lix2/build/src/libstore/build/worker.cc:320:23
5 0x734ba59b93d8 in nix::Store::buildPathsWithResults(std::vector<nix::DerivedPath, std::allocator<nix::DerivedPath>> const&, nix::BuildMode, std::shared_ptr<nix::Store>) /home/jade/lix/lix2/build/src/libstore/build/entry-points.cc:60:12
6 0x734ba663c107 in nix::Installable::build2(nix::ref<nix::Store>, nix::ref<nix::Store>, nix::Realise, std::vector<nix::ref<nix::Installable>, std::allocator<nix::ref<nix::Installable>>> const&, nix::BuildMode) /home/jade/lix/lix2/build/src/libcmd/installables.cc:637:36
Change-Id: Id0e651e480bebf6356733b01bc639e9bb59c7bd0
In b469c6509b, the ca-certificates file was
missed. It should be copied too so that we don't end up bind-mounting a broken
symlink.
Change-Id: Ic9b292d602eb94b0e78f77f2a27a19d24665783c
check goals for timeouts first, and their activity fds only if no
timeout has occurred. checking for timeouts *after* activity sets
us up for assertion failures by running multiple build completion
notifiers, the first of which will kill/reap the the goal process
and consuming the Pid instance. when the second notifier attempts
to do the same it will core dump with an assertion failure in Pid
and take down not only the single goal, but the entire daemon and
all goals it was building. luckily this is rare in practice since
it requires a build to both finish and time out at the same time.
writing a test for this is not feasible due to how much it relies
on scheduling to actually trigger the underlying bug, but on idle
machines it can usually be triggered by running multiple sleeping
builds with timeout set to the sleep duration and `--keep-going`:
nix-build --timeout 10 --builders '' --keep-going -E '
with import <nixpkgs> {};
builtins.genList
(i: runCommand "foo-${toString i}" {} "sleep 10")
100
'
Change-Id: I394d36b2e5ffb909cf8a19977d569bbdb71cb67b
The `builder` local variable and duplicate `args.push_back` are no
longer required since the Darwin sandbox stopped using `sandbox-exec`.
The `drv->isBuiltin` check is not required either, as args are not
accessed when the builder is builtin.
Change-Id: I80b939bbd6f727b01793809921810ff09b579d54
Seccomp filtering and the no-new-privileges functionality improve the security
of the sandbox, and have been enabled by default for a long time. In
https://git.lix.systems/lix-project/lix/issues/265 it was decided that they
should be enabled unconditionally. Accordingly, remove the allow-new-privileges
(which had weird behavior anyway) and filter-syscall settings, and force the
security features on. Syscall filtering can still be enabled at build time to
support building on architectures libseccomp doesn't support.
Change-Id: Iedbfa18d720ae557dee07a24f69b2520f30119cb
Move the identical static `chmod_` functions in libstore to
libutil. the function is called `chmodPath` instead of `chmod`
as otherwise it will shadow the standard library chmod in the nix
namespace, which is somewhat confusing.
Change-Id: I7b5ce379c6c602e3d3a1bbc49dbb70b1ae8f7bad
it's no longer used. it really shouldn't have existed this long since it
was just a mashup of both std::promise and std::packaged_task in a shape
that makes composition unnecessarily difficult. all but a single case of
Callback pattern calls were fully synchronous anyway, and even this sole
outlier was by far not important enough to justify the extra complexity.
Change-Id: I208aec4572bf2501cdbd0f331f27d505fca3a62f
this is the *only* real user of file transfer download completion
callbacks, and a pretty spurious user at that (seeing how nothing
here is even turned on by default and indeed a dependency of path
substitution which *isn't* async, and concurrency-limited). it'll
be a real pain to keep this around, and realistically it would be
a lot better to overhaul substitution in general to be *actually*
async. that requires a proper async framework footing though, and
we don't have anything of the sort, but it's also blocking *that*
Change-Id: I1bf671f217c654a67377087607bf608728cbfc83
The fix for the Darwin vulnerability in ecdbc3b207
also broke setting `__sandboxProfile` when `sandbox=relaxed` or
`sandbox=false`. This cppnix change fixes `sandbox=relaxed` and
adds a suitable test.
Co-Authored-By: Artemis Tosini <lix@artem.ist>
Co-Authored-By: Eelco Dolstra <edolstra@gmail.com>
Change-Id: I40190f44f3e1d61846df1c7b89677c20a1488522
this seems to be an oversight, considering that regular substitutions
are concurrency-limited. while not particularly necessary at present,
once we've removed the `Callback` based interfaces it will be needed.
Change-Id: Ide2d08169fcc24752cbd07a1d33fb8482f7034f5
This was found when `logrotate.conf` failed to build in a NixOS system
with:
/nix/store/26zdl4pyw5qazppj8if5lm8bjzxlc07l-coreutils-9.3/bin/id: cannot find name for group ID 30000
This was surprising because it seemed to mean that /etc/group was busted
in the sandbox. Indeed it was:
root:x:0:
nixbld:!💯
nogroup:x:65534:
We diagnosed this to sandboxUid() being called before
usingUserNamespace() was called, in setting up /etc/group inside the
sandbox. This code desperately needs refactoring.
We also moved the /etc/group code to be with the /etc/passwd code, but
honestly this code is all spaghetti'd all over the place and needs some
more serious tidying than we did here.
We also moved some checks to be earlier to improve locality with where
the things they are checking come from.
Change-Id: Ie29798771f3593c46ec313a32960fa955054aceb
With Linux kernel >=6.6 & glibc 2.39 a `fchmodat2(2)` is available that
isn't filtered away by the libseccomp sandbox.
Being able to use this to bypass that restriction has surprising results
for some builds such as lxc[1]:
> With kernel ≥6.6 and glibc 2.39, lxc's install phase uses fchmodat2,
> which slips through https://github.com/NixOS/nix/blob/9b88e5284608116b7db0dbd3d5dd7a33b90d52d7/src/libstore/build/local-derivation-goal.cc#L1650-L1663.
> The fixupPhase then uses fchmodat, which fails.
> With older kernel or glibc, setting the suid bit fails in the
> install phase, which is not treated as fatal, and then the
> fixup phase does not try to set it again.
Please note that there are still ways to bypass this sandbox[2] and this is
mostly a fix for the breaking builds.
This change works by creating a syscall filter for the `fchmodat2`
syscall (number 452 on most systems). The problem is that glibc 2.39
is needed to have the correct syscall number available via
`__NR_fchmodat2` / `__SNR_fchmodat2`, but this flake is still on
nixpkgs 23.11. To have this change everywhere and not dependent on the
glibc this package is built against, I added a header
"fchmodat2-compat.hh" that sets the syscall number based on the
architecture. On most platforms its 452 according to glibc with a few
exceptions:
$ rg --pcre2 'define __NR_fchmodat2 (?!452)'
sysdeps/unix/sysv/linux/x86_64/x32/arch-syscall.h
58:#define __NR_fchmodat2 1073742276
sysdeps/unix/sysv/linux/mips/mips64/n32/arch-syscall.h
67:#define __NR_fchmodat2 6452
sysdeps/unix/sysv/linux/mips/mips64/n64/arch-syscall.h
62:#define __NR_fchmodat2 5452
sysdeps/unix/sysv/linux/mips/mips32/arch-syscall.h
70:#define __NR_fchmodat2 4452
sysdeps/unix/sysv/linux/alpha/arch-syscall.h
59:#define __NR_fchmodat2 562
I added a small regression-test to the setuid integration-test that
attempts to set the suid bit on a file using the fchmodat2 syscall.
I confirmed that the test fails without the change in
local-derivation-goal.
Additionally, we require libseccomp 2.5.5 or greater now: as it turns
out, libseccomp maintains an internal syscall table and
validates each rule against it. This means that when using libseccomp
2.5.4 or older, one may pass `452` as syscall number against it, but
since it doesn't exist in the internal structure, `libseccomp` will refuse
to create a filter for that. This happens with nixpkgs-23.11, i.e. on
stable NixOS and when building Lix against the project's flake.
To work around that
* a backport of libseccomp 2.5.5 on upstream nixpkgs has been
scheduled[3].
* the package now uses libseccomp 2.5.5 on its own already. This is to
provide a quick fix since the correct fix for 23.11 is still a staging cycle
away.
We still need the compat header though since `SCMP_SYS(fchmodat2)`
internally transforms this into `__SNR_fchmodat2` which points to
`__NR_fchmodat2` from glibc 2.39, so it wouldn't build on glibc 2.38.
The updated syscall table from libseccomp 2.5.5 is NOT used for that
step, but used later, so we need both, our compat header and their
syscall table 🤷
Relevant PRs in CppNix:
* https://github.com/NixOS/nix/pull/10591
* https://github.com/NixOS/nix/pull/10501
[1] https://github.com/NixOS/nixpkgs/issues/300635#issuecomment-2031073804
[2] https://github.com/NixOS/nixpkgs/issues/300635#issuecomment-2030844251
[3] https://github.com/NixOS/nixpkgs/pull/306070
(cherry picked from commit ba6804518772e6afb403dd55478365d4b863c854)
Change-Id: I6921ab5a363188c6bff617750d00bb517276b7fe
Currently LocalDerivationGoal allows setting `__sandboxProfile`
to add sandbox parameters on Darwin when `sandbox=true`.
This was only supposed to have an effect when `sandbox=relaxed`
Change-Id: Ide44ee82d7e4d6b545285eab26547e7014817d3f
This replaces the external sandbox-exec call with direct calls into
libsandbox. This API is technically deprecated and is missing some
prototypes, but all major browsers depend on it, so it is unlikely to
materially change without warning.
This commit also ensures the netrc file is only written if the
derivation is in fact meant to be able to access the internet.
This change commits a sin of not actually actively declaring its
dependency on macOS's libsandbox.dylib; this is due to the dylib
cache in macOS making that explicit dependency unnecessary. In the
future this might become a problem, so this commit marks our sins.
Co-authored-by: Artemis Tosini <lix@artem.ist>
Co-authored-by: Lunaphied <lunaphied@lunaphied.me>
Change-Id: Ia302141a53ce7b0327c1aad86a117b6645fe1189
Either the contents of `line` could cause format errors, or this usage
is Technically safe. However, I trust nothing, especially with
boost::format.
Change-Id: I07933b20bde3b305a6e5d61c2a7bab6ecb042ad9
eldritch horrors