Commit graph

4285 commits

Author SHA1 Message Date
c7d97802e4 libutil: rename and optimize closeMostFDs
this is only used to close non-stdio files in derivation sandboxes. we
may as well encode that in its name, drop the unnecessary integer set,
and use close_range to deal with the actual closing of files. not only
is this clearer, it also makes sandbox setup on linux fast by 1ms each

Change-Id: Id90e259a49c7bc896189e76bfbbf6ef2c0bcd3b2
2024-08-09 19:59:17 +00:00
35a2f28a46 libstore: deprecate the build-hook setting
implementing a build hook is pretty much impossible without either being
a nix, or blindly forwarding the important bits of all build requests to
some kind of nix. we've found no uses of build-hook in the wild, and the
build-hook protocol (apart from being entirely undocumented) is not able
to convey any kind of versioning information between hook and daemon. if
we want to upgrade this infrastructure (which we do), this must not stay

Change-Id: I1ec4976a35adf8105b8ca9240b7984f8b91e147e
2024-08-09 19:30:45 +00:00
790d1079e1 Merge changes Ib7c80826,I636f8a71,I67669b98 into main
* changes:
  perl: un-autos your conf
  build: declare all the deps as -isystem
  darwin: workaround PROC_PIDLISTFDS on processes with no fds
2024-08-09 19:24:29 +00:00
9682ab4f38 Merge changes I6358a393,I2d9f276b,Idd096dc9 into main
* changes:
  clang-tidy: write a lint for charptr_cast
  tree-wide: automated migration to charptr_cast
  clang-tidy: enforce the new rules
2024-08-08 23:09:30 +00:00
757041c3e7 Merge changes I526cceed,Ia4e2f1fa,I22e66972,I9fbd55a9,Ifca22e44 into main
* changes:
  sqlite: add a Use::fromStrNullable
  util: implement charptr_cast
  tree-wide: fix a pile of lints
  refactor: make HashType and Base enum classes for type safety
  build: integrate clang-tidy into CI
2024-08-08 22:43:10 +00:00
4ed8461cac sqlite: add a Use::fromStrNullable
There were several usages of the raw sqlite primitives along with C
style casts, seemingly because nobody thought to use an optional for
getting a string or NULL.

Let's fix this API given we already *have* a wrapper.

Change-Id: I526cceedc2e356209d8fb62e11b3572282c314e8
2024-08-08 14:53:17 -07:00
a85c4ce535 tree-wide: automated migration to charptr_cast
The lint did it :3

Change-Id: I2d9f276b01ebbf14101de4257ea13e44ff6fe0a0
2024-08-08 14:53:17 -07:00
e34833c025 tree-wide: fix a pile of lints
This:
- Converts a bunch of C style casts into C++ casts.
- Removes some very silly pointer subtraction code (which is no more or
  less busted on i686 than it began)
- Fixes some "technically UB" that never had to be UB in the first
  place.
- Makes finally follow the noexcept status of the inner function. Maybe
  in the future we should ban the function from not being noexcept, but
  that is not today.
- Makes various locally-used exceptions inherit from std::exception.

Change-Id: I22e66972602604989b5e494fd940b93e0e6e9297
2024-08-08 14:53:17 -07:00
370ac940dd refactor: make HashType and Base enum classes for type safety
Change-Id: I9fbd55a9d50464a56fe11cb42a06a206914150d8
2024-08-08 14:53:17 -07:00
a957219df2 libstore: make Worker::waitForInput private
Change-Id: I71a42acd5a4a9a18b55cf754cdf9896614134398
2024-08-08 12:02:17 +00:00
ba85e501ce libstore: make Worker status flags private
Change-Id: I16ec8994c6448d70b686a2e4c10f19d4e240750d
2024-08-08 12:02:17 +00:00
fc987b4123 libstore: remove Goal::addWaitee
Change-Id: I1b00d1a537d84790878cb0e81aaa1cbaa143d62d
2024-08-08 12:02:17 +00:00
4c3010a1be libstore: make Worker::wakeUp private
Change-Id: Iffa55272fe6ef4adaf3e9d4d25e5339792c2e460
2024-08-08 12:02:17 +00:00
3ecb46e3e7 libstore: make Worker::waitForAWhile private
Change-Id: I0cdcd436ee71124ca992b4f4fe307624a25f11e9
2024-08-08 12:02:17 +00:00
b33c969519 libstore: make Worker::waitForBuildSlot private
Change-Id: I02a54846cd65622edbd7a1d6c24a623b4a59e5b3
2024-08-08 12:02:17 +00:00
0800a81a95 Merge "oops: fix warning about catching polymorphic exception" into main 2024-08-07 19:06:54 +00:00
27a63db710 Merge "fix: warn and document when advanced attributes will have no impact due to __structuredAttrs" into main 2024-08-07 10:38:39 +00:00
1437d3df15 darwin: workaround PROC_PIDLISTFDS on processes with no fds
This has been causing various seemingly spurious CI failures as well as
some failures on people running tests on beta builds.

lix> ++(nix-collect-garbage-dry-run.sh:20) nix-store --gc --print-dead
lix> ++(nix-collect-garbage-dry-run.sh:20) wc -l
lix> finding garbage collector roots...
lix> error: Listing pid 87261 file descriptors: Undefined error: 0

There is no real way to write a proper test for this, other than to
start a process like the following:

int main(void) {
    for (int i = 0; i < 1000; ++i) {
        close(i);
    }
    sleep(10000);
}

and then let Lix's gc look at it.

I have a relatively high confidence this *will* fix the problem since I
have manually confirmed the behaviour of the libproc call is
as-unexpected, and it would perfectly explain the observed symptom.

Fixes: lix-project/lix#446
Change-Id: I67669b98377af17895644b3bafdf42fc33abd076
2024-08-07 02:52:00 -07:00
d280e4990c oops: fix warning about catching polymorphic exception
This was introduced in I0fc80718eb7e02d84cc4b5d5deec4c0f41116134 and
unnoticed since it only appears in gcc builds.

Change-Id: I1de80ce2a8fab63efdca7ca0de2a302ceb118267
2024-08-06 22:45:19 -07:00
529eed74c4 Merge changes I0fc80718,Ia182b86f,I355f82cb,I8a9b58fa,Id89f8a1f, ... into main
* changes:
  tree-wide: fix various lint warnings
  flake & doxygen: update tagline
  nix flake metadata: print modified dates for input flakes
  cli: eat terminal codes from stdout also
  Implement forcing CLI colour on, and document it better
  manual: fix a syntax error in redirects.js that made it not do anything
  misc docs/meson tidying
  build: implement clang-tidy using our plugin
2024-08-07 00:50:30 +00:00
2c48460850
libstore/linux: precompile and cache the seccomp BPF
The growth of the seccomp filter in 127ee1a101
made its compilation time significant (roughly 10 milliseconds have been
measured on one machine). For this reason, it is now precompiled and cached in
the parent process so that this overhead is not hit for every single build. It
is still not optimal when going through the daemon, because compilation still
happens once per client, but it's better than before and doing it only once for
the entire daemon requires excessive crimes with the current architecture.

Fixes: lix-project/lix#461
Change-Id: I2277eaaf6bab9bd74bbbfd9861e52392a54b61a3
2024-08-06 19:10:33 +02:00
403fa9e2b6
libstore/linux: compile the seccomp BPF explicitly
This is a preparation for precompiling the filter, which is done separately.
The behaviour should be unchanged for now.

Change-Id: I899aa7242962615949208597aca88913feba1cb8
2024-08-06 18:31:40 +02:00
741d3b441c
libstore: add LocalDerivationGoal setupSyscallFilter hook
The seccomp setup code was a huge chunk of conditionally compiled
platform-specific code. For this reason, it is appropriate to move it to the
platform-specific implementation file. Ideally its setup could be moved a bit
to make it happen at the same place as the Darwin restrictions, but that change
is going to be less mechanical.

Change-Id: I496aa3c4fabf34656aba1e32b0089044ab5b99f8
2024-08-06 18:27:09 +02:00
ca9d3e6e00 tree-wide: fix various lint warnings
Change-Id: I0fc80718eb7e02d84cc4b5d5deec4c0f41116134
2024-08-04 20:55:45 -07:00
Tom Bereknyei
7fc481396c
fix: warn and document when advanced attributes will have no impact due to __structuredAttrs
Backport of https://github.com/NixOS/nix/pull/10884.

Change-Id: I82cc2794730ae9f4a9b7df0185ed0aea83efb65a
2024-08-03 13:32:51 +02:00
66469fc281 libstore: move Goal::waiteeDone into Worker::goalFinished
this begins a long and arduous journey to remove all result state from
Goal, to eventually drop the std::enable_shared_from_this base, and to
completely eliminate all unsynchronized modification of states of both
Goal and Worker. by the end of this we will hopefully be able to start
and reap multiple derivation builds in parallel, which should speed up
the process quite a bit (at least for short local builds, others might
not notice a large difference. the build hooks will remain a problem.)

Change-Id: I57dcd9b2cab4636ed4aa24cdec67124fef883345
2024-08-03 00:08:44 +00:00
32ca194ebf Merge "libstore/ssh: only resume the logger when we paused it" into main 2024-08-02 16:59:44 +00:00
a93dade821
libstore/ssh: only resume the logger when we paused it
In the SSH code, the logger was conditionally paused, but unconditionally
resumed. This was fine as long as resuming the logger was idempotent. Starting
with 0dd1d8ca1c, it isn't any more, and the
behaviour of the code in question was missed. Consequently, an assertion
failure is triggered for example when performing builds against an "SSH" store
on localhost. Fix the issue by only resuming the logger when it has actually
been paused.

Fixes: lix-project/lix#458
Change-Id: Ib1e4d047744a129f15730b7216f9c9368c2f4211
2024-08-02 18:38:14 +02:00
e5177dddff libstore: move Goal::amDone to Worker
we still mutate goal state to store the results of any given goal run,
but now we also have that information in Worker and could in theory do
something else with it. we could return a map of goal to goal results,
which would also let us better diagnose failures of subgoals (at all).

Change-Id: I1df956bbd9fa8cc9485fb6df32918d68dda3ff48
2024-08-02 13:52:15 +00:00
dfcab1c3f0 libstore: return finishedness from Goal methods
this is the first step towards removing all result-related mutation of
Goal state from goal implementations themselves, and into Worker state
instead. once that is done we can treat all non-const Goal fields like
private state of the goal itself, and make threading of goals possible

Change-Id: I69ff7d02a6fd91a65887c6640bfc4f5fb785b45c
2024-08-02 13:52:15 +00:00
724b345eb9 libstore: encapsulate worker build hook state
once goals run on multiple threads these fields must by synchronized as
one, or we try to run build hooks to often (or worse, not often enough)

Change-Id: I47860e46fe5c6db41755b2a3a1d9dbb5701c4ca4
2024-08-02 13:52:15 +00:00
97a389b0be libstore: move Goal::getBuildResult to BuildResult
there are no other uses for this yet, but asking for just a subset of
outputs does seem at least somewhat useful to have as a generic thing

Change-Id: I30ff5055a666c351b1b086b8d05b9d7c9fb1c77a
2024-07-30 16:37:13 +00:00
d265dd5993 libstore: count all substitutions toward the same limit
limiting CA substitutions was a rather recent addition, and it used a
dedicated counter to not interfere with regular substitutions. though
this works fine it somewhat contradicts the documentation; job limits
should apply to all kinds of substitutions, or be one limit for each.

Change-Id: I1505105b14260ecc1784039b2cc4b7afcf9115c8
2024-07-30 15:37:27 +00:00
d9af753a7f libstore: always wake up goals on EOF
all goals do this. it makes no sense to not notify a goal of EOF
conditions because this is the universal signal for "child done"

Change-Id: Ic3980de312547e616739c57c6248a8e81308b5ee
2024-07-30 15:37:27 +00:00
6c0dcd1220 libstore: simplify substitution handleEOF
both substitution goals add only this single fd to their wait set.

Change-Id: Ibf921f5bb3919106208a0871523b32c8f67fb3d3
2024-07-30 15:37:27 +00:00
548c973e82 libstore: remove Worker::updateProgress
just update progress every time a goal has returned from work(). there
seem to be no performance penalties, and the code is much simpler now.

Change-Id: I288ee568b764ee61f40a498d986afda49987cb50
2024-07-29 22:16:11 +00:00
3058029fba
libutil: Add bindPath function from libstore
bindPath/doBind is a useful function in build that is used in several
parts of LocalDerivationGoal. Moving this function makes it easier to
split LocalDerivationGoal implementation between several files.

Change-Id: Ic5a0768479c153c1aa3ed425f12604b20bbf0f42
2024-07-27 19:40:40 +00:00
d945e89e19 Merge changes I45d3895f,I541be3ea,Ibe51416d into main
* changes:
  libstore/build: block io_uring
  libstore/build: use an allowlist approach to syscall filtering
  libstore/build: always treat seccomp setup failures as fatal
2024-07-26 07:08:35 +00:00
c4c7cb7613 Merge changes Ic0dfcfe2,Ibe73851f,Ia7a8df1c,I400b2031 into main
* changes:
  package.nix: remove dead code
  diff-closures: remove gratuitous copy
  tree-wide: NULL -> nullptr
  libutil: rip out GNU Hurd support code
2024-07-25 18:05:41 +00:00
e7188e211a
libstore/build: block io_uring
Unfortunately, io_uring is totally opaque to seccomp, and while currently there
are no dangerous operations implemented, there is no guarantee that it remains
this way. This means that io_uring should be blocked entirely to ensure that
the sandbox is future-proof. This has not been observed to cause issues in
practice.

Change-Id: I45d3895f95abe1bc103a63969f444c334dbbf50d
2024-07-25 18:24:45 +02:00
127ee1a101
libstore/build: use an allowlist approach to syscall filtering
Previously, system call filtering (to prevent builders from storing files with
setuid/setgid permission bits or extended attributes) was performed using a
blocklist. While this looks simple at first, it actually carries significant
security and maintainability risks: after all, the kernel may add new syscalls
to achieve the same functionality one is trying to block, and it can even be
hard to actually add the syscall to the blocklist when building against a C
library that doesn't know about it yet. For a recent demonstration of this
happening in practice to Nix, see the introduction of fchmodat2 [0] [1].

The allowlist approach does not share the same drawback. While it does require
a rather large list of harmless syscalls to be maintained in the codebase,
failing to update this list (and roll out the update to all users) in time has
rather benign effects; at worst, very recent programs that already rely on new
syscalls will fail with an error the same way they would on a slightly older
kernel that doesn't support them yet. Most importantly, no unintended new ways
of performing dangerous operations will be silently allowed.

Another possible drawback is reduced system call performance due to the larger
filter created by the allowlist requiring more computation [2]. However, this
issue has not convincingly been demonstrated yet in practice, for example in
systemd or various browsers. To the contrary, it has been measured that the the
actual filter constructed here has approximately the same overhead as a very
simple filter blocking only one system call.

This commit tries to keep the behavior as close to unchanged as possible. The
system call list is in line with libseccomp 2.5.5 and glibc 2.39, which are the
latest versions at the point of writing. Since libseccomp 2.5.5 is already a
requirement and the distributions shipping this together with older versions of
glibc are mostly not a thing any more, this should not lead to more build
failures any more.

[0] https://github.com/NixOS/nixpkgs/issues/300635
[1] https://github.com/NixOS/nix/issues/10424
[2] https://github.com/flatpak/flatpak/pull/4462#issuecomment-1061690607

Change-Id: I541be3ea9b249bcceddfed6a5a13ac10b11e16ad
2024-07-25 18:24:40 +02:00
233408f677
libstore/build: always treat seccomp setup failures as fatal
In f047e4357b, I missed the behavior that if
building without a dedicated build user (i.e. in single-user setups), seccomp
setup failures are silently ignored. This was introduced without explanation 7
years ago (ff6becafa8). Hopefully the only
use-case nowadays is causing spurious test suite successes when messing up the
seccomp filter during development. Let's try removing it.

Change-Id: Ibe51416d9c7a6dd635c2282990224861adf1ceab
2024-07-25 18:21:26 +02:00
8d12e0fbb7 fix building with Musl, fixing static builds
Musl stdout macro expands¹ to something that isn't a valid identifier,
so we get syntax errors when compiling usage of a method called stdout
with Musl's stdio.h.

[1]: https://git.musl-libc.org/cgit/musl/tree/include/stdio.h?id=ab31e9d6a0fa7c5c408856c89df2dfb12c344039#n67

Change-Id: I10e6f6a49504399bf8edd59c5d9e4e62449469e8
2024-07-24 17:21:40 +00:00
2436f2110a tree-wide: NULL -> nullptr
This is slightly more type safe and is more in line with modern C++.

Change-Id: Ia7a8df1c7788085020d1bdc941d6f9cee356144e
2024-07-23 21:06:55 +02:00
53f3e39815
libstore: Add FreeBSD findPlatformRoots
Use libprocstat to find garbage collector roots on FreeBSD.
Tested working on a FreeBSD machine, although there is no CI yet

Change-Id: Id36bac8c3de6cc4de94e2d76e9663dd4b76068a9
2024-07-23 17:49:33 +00:00
472ff1b833 libstore: keep Goal errors as unique_ptrs
Error is pretty large, and most goals do not fail. this alone more than
halves the size of Goal on x86_64-linux, from 720 bytes down to 344. in
derived classes the difference is not as dramatic, but even the largest
derived class (`LocalDerivationGoal`) loses almost 20% of its footprint

Change-Id: Ifda8f94c81b6566eeb3e52d55d9796ec40c7bce8
2024-07-22 19:01:40 +00:00
7bf1aff44a libstore: remove an always-defaulted argument
Change-Id: I3c7f17d5492a16bb54480fa1aa384b96fba72d61
2024-07-22 19:01:40 +00:00
58a91d70c9 libstore: use std::async instead of Goal threads
the goals are either already using std::async and merely forgot to
remove std::thread vestiges or they emulate async with threads and
promises. we can simply use async directly everywhere for clarity.

Change-Id: I3f05098310a25984f10fff1e68c573329002b500
2024-07-22 19:01:40 +00:00
ad36fb43ad libstore: remove addToWeakGoals
under owner_less it's equivalent to insert(), only sometimes a little
bit faster because it does not construct a weak_ptr if the goal is in
the set already. this small difference in performance does not matter
here and c++23 will make insert transparent anyway, so we can drop it

Change-Id: I7cbd7d6e0daa95d67145ec58183162f6c4743b15
2024-07-22 19:01:40 +00:00
d70e045f90 libstore: remove Goal::ecBusy
this should be an optional. "busy" is not an *exit* code!

Change-Id: Ic231cb27b022312b1a7a7b9602f32845b7a9c934
2024-07-22 19:01:40 +00:00
20f53346df libstore: remove unused Worker::waitForAnyGoal
Change-Id: Ia3ebd434b17052b6760ce74d8e20025a72148613
2024-07-22 19:01:40 +00:00
c74eb81356 enable -Werror=suggest-override
*accidentally* overriding a function is almost guaranteed to be an
error. overriding a function without labeling it as such is merely
bad style, but bad style that makes the code harder to understand.

Change-Id: Ic0594f3d1604ab6b3c1a75cb5facc246effe45f0
2024-07-22 16:26:55 +00:00
94a8e5fe0d Merge "libstore/binary-cache-store: use correct buffer size for NAR decompression" into main 2024-07-21 10:42:33 +00:00
4fa6961aa2 Merge "gc: refactor the gc server thread out into a class without changing it" into main 2024-07-21 10:36:10 +00:00
391088900e
libstore/binary-cache-store: use correct buffer size for NAR decompression
Due to a leftover from a previous version where the buffer was allocated on the
stack, the change introduced in commit 4ec87742a1
accidentally passes the size of a pointer as the size of the buffer to the
decompressor. Since the former is much smaller (usually 8 bytes instead of 64
kilobytes), this is safe, but leads to considerable overhead; most notably, due
to excessive progress reports, which happen for each chunk. Pass the proper
buffer size instead.

Change-Id: If4bf472d33e21587acb5235a2d99e3cb10914633
2024-07-21 11:28:23 +02:00
1917e6c765 Merge "Fix namespace warning being emitted if sandbox is disabled" into main 2024-07-20 22:14:33 +00:00
0109368c3f libutil: make basic loggers thread-safe
SimpleLogger is not fully thread-safe, and all loggers that wrap it are
also not safe accordingly. this does not affect much, but in rare cases
it can cause interleaving of messages on stderr when used with the json
or raw log formats. the fix applied here is a bit of a hack, but fixing
this properly requires rearchitecting the logger infrastructure. nested
loggers are not the most natural abstraction here, and it is biting us.

Change-Id: Ifbf34fe1e85c60e73b59faee50e7411c7b5e7c12
2024-07-20 12:33:49 +00:00
3da41fdb82 Fix namespace warning being emitted if sandbox is disabled
If useChroot = false, and user namespaces aren't available for some
reason (e.g. within a Docker container), this fixes a pointless warning
being emitted, as we would never attempt to use them even if they were
available.

Change-Id: Ibcee91c088edd2cd19e70218d5a5802bff8f537b
2024-07-19 19:14:54 -04:00
77ff799cc8 gc: refactor the gc server thread out into a class without changing it
This removes a *whole load* of variables from scope and enforces thread
boundaries with the type system.

There is not much change of significance in here, so the things to watch
out for while reviewing it are primarily that the destructor ordering
may have changed inadvertently, I think.

Change-Id: I3cd87e6d5a08dfcf368637407251db22a8906316
2024-07-19 20:55:55 +00:00
26e56780ca Fixup a bunch of references to nixos.org manuals
(plus one reference to CppNix github)

Change-Id: Id8b3d2897f3b54e286861805cfd421adc4d5de47
2024-07-18 19:27:33 +00:00
d094dd0396 libstore: remove remaining sinkToSource uses
Change-Id: Id1ee0d2ad4a3774f4bbb960d76f0f76ac4f3eff9
2024-07-16 01:50:16 +00:00
6b4d46e9e0 libstore: remove WriteConn::sink fields
we no longer need these since we're no longer using sinks to serialize things.

Change-Id: Iffb1a3eab33c83f611c88fa4e8beaa8d5ffa079b
2024-07-16 00:57:42 +00:00
a5d1f69841 libstore: generatorize protocol serializers
this is cursed. deeply and profoundly cursed. under NO CIRCUMSTANCES
must protocol serializer helpers be applied to temporaries! doing so
will inevitably cause dangling references and cause the entire thing
to crash. we need to do this even so to get rid of boost coroutines,
and likewise to encapsulate the serializers we suffer today at least
a little bit to allow a gradual migration to an actual IPC protocol.

(this isn't a problem that's unique to generators. c++ coroutines in
general cannot safely take references to arbitrary temporaries since
c++ does not have a lifetime system that can make this safe. -sigh-)

Change-Id: I2921ba451e04d86798752d140885d3c5cc08e146
2024-07-16 00:57:42 +00:00
5271424d14 libstore: remove a sinkToSouce from old daemon protocol
this doesn't have a test because this code path is only reached by
clients that predate 2.4, and we really should not be caring about
those any more right now. even the test suite doesn't, and the few
tests that might care are disabled because they will not even work

Change-Id: Id9eb190065138fedb2c7d90c328ff9eb9d97385b
2024-07-16 00:57:42 +00:00
3447dbfb2c libstore: rewrite narFromPath as generator
Change-Id: Ifa783c2c65c06ddd1d0212016d5bfd07666ea91c
2024-07-15 21:50:25 +00:00
917c9bdee7 language: cleanly ban integer overflows
This also bans various sneaking of negative numbers from the language
into unsuspecting builtins as was exposed while auditing the
consequences of changing the Nix language integer type to a newtype.

It's unlikely that this change comprehensively ensures correctness when
passing integers out of the Nix language and we should probably add a
checked-narrowing function or something similar, but that's out of scope
for the immediate change.

During the development of this I found a few fun facts about the
language:
- You could overflow integers by converting from unsigned JSON values.
- You could overflow unsigned integers by converting negative numbers
  into them when going into Nix config, into fetchTree, and into flake
  inputs.

  The flake inputs and Nix config cannot actually be tested properly
  since they both ban thunks, however, we put in checks anyway because
  it's possible these could somehow be used to do such shenanigans some
  other way.

Note that Lix has banned Nix language integer overflows since the very
first public beta, but threw a SIGILL about them because we run with
-fsanitize=signed-overflow -fsanitize-undefined-trap-on-error in
production builds. Since the Nix language uses signed integers, overflow
was simply undefined behaviour, and since we defined that to trap, it
did.

Trapping on it was a bad UX, but we didn't even entirely notice
that we had done this at all until it was reported as a bug a couple of
months later (which is, to be fair, that flag working as intended), and
it's got enough production time that, aside from code that is IMHO buggy
(and which is, in any case, not in nixpkgs) such as
lix-project/lix#445, we don't think
anyone doing anything reasonable actually depends on wrapping overflow.

Even for weird use cases such as doing funny bit crimes, it doesn't make
sense IMO to have wrapping behaviour, since two's complement arithmetic
overflow behaviour is so *aggressively* not what you want for *any* kind
of mathematics/algorithms. The Nix language exists for package
management, a domain where bit crimes are already only dubiously in
scope to begin with, and it makes a lot more sense for that domain for
the integers to never lose precision, either by throwing errors if they
would, or by being arbitrary-precision.

This change will be ported to CppNix as well, to maintain language
consistency.

Fixes: lix-project/lix#423

Change-Id: I51f253840c4af2ea5422b8a420aa5fafbf8fae75
2024-07-13 00:59:33 +02:00
dde51af97d Use std::strong_ordering for version comparison
The actual motive here is the avoidance of integer overflow if we were
to make these use checked NixInts and retain the subtraction.

However, the actual *intent* of this code is a three-way comparison,
which can be done with operator<=>, so we should just do *that* instead.

Change-Id: I7f9a7da1f3176424b528af6d1b4f1591e4ab26bf
2024-07-12 16:48:28 +02:00
4b109ec1a8 libstore: remove upcast_goal
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
2024-07-11 21:31:52 +00:00
a5d431a911 libstore: turn copyNAR into a generator
Change-Id: Id452f6a03faa1037ff13af0f63e32883966ff40d
2024-07-11 20:37:27 +00:00
31478c810a libutil: remove makeDecompressionSink
the sole remaining user of this function can use makeDecompressionSource
instead, while making the sinkToSource in the caller unnecessary as well

Change-Id: I4258227b5dbbb735a75b477d8a57007bfca305e9
2024-07-11 11:39:18 +00:00
5587dbdcf0 libstore: make BinaryCacheStore::getFile return a source
this lets us remove the last true remaining uses of
makeDecompressionSink.

Change-Id: I146ca2bbe1a9ae9a367117a7b8a304b23a63e5e2
2024-07-11 11:39:18 +00:00
df8851f286 libutil: rewrite RewritingSink as source
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
2024-07-11 11:39:18 +00:00
d461cc1d7b
libstore: make LocalDerivationGoal::needsHashRewrite virtual
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
2024-07-07 18:06:08 +00:00
5af76dee37 libutil: turn HashModuloSink into a free function
Change-Id: I5878007502fa68c2816a0f4c61f7d0e60bdde702
2024-07-06 12:36:37 +02:00
4162a66cee libutil: return sources from runProgram2
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
2024-07-06 12:36:36 +02:00
b6a08a2fed libutil: return a program handle from runProgram2
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
2024-07-05 22:28:16 +00:00
f4f6d1d8e2 libutil: convert readFileSource to a generator
Change-Id: I5f92b15fd367d46eb047d74ab6e317b4f51a46d3
2024-07-05 22:28:16 +00:00
06220a71c1 libstore: convert dumpPath to a generator
Change-Id: Ic4cf5562504aa29130304469936f958c0426e5ef
2024-07-05 22:28:16 +00:00
e040b762a4
libstore: add LocalDerivationGoal startChild hook
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
2024-07-03 22:37:41 +00:00
af1dcc2d5e
libstore: Add LocalDerivationGoal prepareSandbox hook
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
2024-07-03 22:16:03 +00:00
5eec6418de libutil: begin porting serialization to generators
generators are a better basis for serializers than streaming into sinks
as we do currently for many reasons, such as being usable as sources if
one wishes to (without requiring an intermediate sink to serialize full
data sets into memory, or boost coroutines to turn sinks into sources),
composing more naturally (as one can just yield a sub-generator instead
of being forced to wrap entire substreams into clunky functions or even
more clunky custom types to implement operator<< on), allowing wrappers
to transform data with clear ownership semantics (removing the need for
explicit memory allocations and Source wrappers), and many other things

Change-Id: I361d89ff556354f6930d9204f55117565f2f7f20
2024-07-03 11:46:53 +00:00
d85309f7ca store: delete obsolete lsof-disabling code
Since Ifa0adda7984e, we don't use this code anymore on macOS, so we have
no reason to have a knob to disable it anymore.

Change-Id: Ie29a8a8978d9aefd4551895f4f9b3cc0827496df
2024-06-27 22:53:36 -07:00
d92712673b store: guess the URL of failing fixed-output derivations
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
2024-06-27 22:44:16 -07:00
d86009bd76 Add build-dir setting, clean up default TMPDIR handling
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
2024-06-24 11:30:32 +03:00
7c3b8229cc Merge "libstore: reduce loglevel of waiting for a machine to build" into main 2024-06-23 16:33:44 +00:00
ce6cb14995 libutil: return Pid from startProcess, not pid_t
Change-Id: Icc8a15090c77f54ea7d9220aadedcd4a19922814
2024-06-23 11:52:49 +00:00
3d155fc509 libutil: give Pid proper resource semantics
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
2024-06-23 11:52:49 +00:00
b43a2e84c4 libutil: make Pid -> pid_t operations explicit
Change-Id: I3137cc140590001fe7ba542844e735944a0a9255
2024-06-23 11:52:49 +00:00
39a1e248c9 libutil: remove sinkToSource eof callback
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
2024-06-23 11:52:49 +00:00
12f5d27363 libstore: Start creating LocalDerivationGoal subclasses
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
2024-06-23 03:33:07 +00:00
fc6a1451af
libstore: reduce loglevel of waiting for a machine to build
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
2024-06-22 17:38:25 +02:00
375f4c0337 Merge "libstore: remove operations that are never called by supported clients" into main 2024-06-21 20:46:18 +00:00
6c29a2a6fc Merge "libstore: fix queryValidPaths concurrency" into main 2024-06-20 05:55:08 +00:00
50472aa5be libstore: remove operations that are never called by supported clients
I did a whole bunch of `git log -S` to find out exactly when all these
things were obsoleted and found the commit in which their usage was
removed, which I have added in either the error message or a comment.

I've also made *some* of the version checks into static asserts for when
we update the minimum supported protocol version.

In the end this is not a lot of code we are deleting, but it's code that
we will never have to support into the future when we build a protocol
bridge, which is why I did it. It is not in the support baseline.

Change-Id: Iea3c80795c75ea74f328cf7ede7cbedf8c41926b
2024-06-19 19:41:04 -07:00
c55dcc6c13 filetransfer: return a Source from download()
without this we will not be able to get rid of makeDecompressionSink,
which in turn will be necessary to get rid of sourceToSink (since the
libarchive archive wrapper *must* be a Source due to api limitations)

Change-Id: Iccd3d333ba2cbcab49cb5a1d3125624de16bce27
2024-06-19 10:50:12 +00:00
11f4a5bc7e libutil: return a source from readFile
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
2024-06-19 10:50:12 +00:00
3425e90d76 libstore: BinaryCacheStore::getFile{ -> Contents}
if we want have getFile return a source instead of consuming a sink
we'll have to disambiguate this overload another way, eg like this.

Change-Id: Ia26de2020c309a37e7ccc3775c1ad1f32e0a778b
2024-06-19 10:50:12 +00:00
c897fba787 store: fix null reference from DerivationGoal::waiteeDone
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
2024-06-18 19:26:54 -07:00
0b9a72524a filetransfer: {up,down}load -> transfer
even the transfer function is not all that necessary since there aren't
that many users, but we'll keep it for now. we could've kept both names
but we also kind of want to use `download` for something else very soon

Change-Id: I005e403ee59de433e139e37aa2045c26a523ccbf
2024-06-18 23:58:25 +00:00
66a9fbb7ff libstore: fix queryValidPaths concurrency
The lock usage was obviously wrong so it was entirely serialized. This
has the predicted speedups, the only question is whether it is sound
because it's exposing a bunch of new code to actual concurrency.

I did audit all the stores' queryPathInfoUncached implementations and
they all look *intended* to be thread safe, but whether that is actually
sound or not: lol lmao. I am highly confident in the s3 one because it
is calling s3 sdk methods that are thread safe and has no actual state.

Others are using Pool and look to be *supposed* to be thread safe, but
unsure if they actually are.

Change-Id: I0369152a510e878b5ac56c9ac956a98d48cd5fef
2024-06-18 23:29:08 +00:00