`MapData::fd` is now a `MapFd`. This means that `MapData` now closes the
file descriptor on drop. In the future we might consider making `MapFd`
hold a `BorrowedFd` but this requires API design work due to overlapping
borrows.
Since `SockMapFd` is no longer `Copy`, attach methods to take it by
reference to allow callers to use it multiple times as they are
accustomed to doing.
`SockMapFd` implements `try_clone`. `MapFd` and `SockMapFd` are now
returned by reference to allow callers to avoid file descriptor cloning
when desired.
This is an API breaking change.
Updates #612.
The primary driver of change here is that `MapData::create` is now a
factory function that returns `Result<Self, _>` rather than mutating
`&mut self`. The remaining changes are consequences of that change, the
most notable of which is the removal of several errors which are no
longer possible.
- Add helper methods to get useful information from the ProgramInfo
object which is returned by the `loaded_programs()` API. Specifically
this code mirrors the `bpftool prog` command in terms of useful fields.
- Add a new API macro to each aya `Program` type to allow us to fetch
its accompanying `ProgramInfo` metadata after its been loaded.
- Add a new ProgramInfo constructor that builds a new instance using
a raw fd.
- Add a smoke test for the loaded_programs() API as well as
all the relevant methods on the ProgramInfo type.
Signed-off-by: Andrew Stoycos <astoycos@redhat.com>
Some of these functions fail to compile when not inlined, so we should
be explicit.
Before deciding on this approach I tried various ways of making all
these functions #[inline(never)] to save instructions but I ran into
blockers:
- These functions currently return Result, which is a structure. This is
not permitted in BPF.
- I tried inventing a newtype that is a #[repr(transparent)] wrapper of
u16, and having these functions return that; however it seems that
even if the object code is legal, the verifier will reject such
functions because the BTF (if present, and it was in my local
experiments) would indicate that the return is a structure.
- I tried having these functions return a plain u16 where 0 means error,
but the verifier still rejected the BTF because the receiver (even if
made into &self) is considered a structure, and forbidden.
We can eventually overcome these problems by "lying" in our BTF once
support for it matures in the bpf-linker repo (e.g. Option<NonZeroU16>
should be perfectly legal as it is guaranteed to be word-sized), but we
aren't there yet, and this is the safest thing we can do for now.
The struct_flavors test previously expected the same thing with and
without relocations. It now expects different values.
Also rename an enum variant "u64" to "S64". This was a typo. Turns out
that U32 is a type that exists in kernel headers, so all enum values are
suffixed with "_VAL".
Remove stdlib.h and the call to exit(). This alone makes the test fail
with a poisoned relocation. Bringing over the map definition makes the
test work again.
This commit fixes the (func|line)_info when we have multiple programs in
the same section. The integration test reloc.bpf.c serves as our test
case here. This required filtering down the (func|line)_info to only
that in scope of the current symbol + then adjusting the offets to
appease the kernel.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
For unclear reasons, two of the integration tests related to uprobes
were resolving a symbol in libc. The integration-test binary can be
built statically, in which case it would not load or reference libc.
Statically linking the integration tests and running them in a VM
without a userland is a convenient mechanism to exercise the tests
against different kernel versions.
The fact that the statically linked integration-test binary does not
load libc is not the only reason these tests failed in such an
environment. In fact, the logic to look in the process's memory
maps was not running (because no pid was being passed).
Separate logic to determine which object file to use when attempting
to resolve a symbol for attaching a uprobe changes its behavior based
on whether that target is an absolute path. If the target is not an
absolute path, the code searches through the LdSoCache. This cache does
not always exist in linux systems; when an attach call is made with a
relative path target and there is no /etc/ld.so.cache file, the attach
call will fail. This commit does not change that behavior, it merely
sidesteps it.
Move the use of clang and llvm-objcopy from run-time to build-time. This
allows the integration tests to run on VMs with simpler userlands.
Create a new CI job to build the integration tests separately from
running them. Ship them from that job to the runner job using github
actions artifacts.
The aya-bpf-macros needed refactoring for:
1. Ease of testing
2. To be consistent with when we use K/V args vs. idents
3. To deprecate the use of `name` to change the exported name of a
function - we now use the symbol table.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
This makes a few changes to the way that Aya reads the ELF object
files.
1. To find programs in a section, we use the symbols table. This allows
for cases where multiple programs could appear in the same section.
2. When parsing our ELF file we build symbols_by_section_index as an
optimization as we use it for legacy maps, BTF maps and now programs.
As a result of theses changes the "NAME" used in `bpf.prog_mut("NAME")`
is now ALWAYS the same as the function name in the eBPF code, making the
user experience more consistent.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
For tests that do networking operations, this allows to have a
clean-state network namespace and interfaces for each test. Mainly, this
avoids "device or resource busy" errors when reusing the loopback
interface across tests.
In release, the trigger functions were being optimized out and the
tests did not work. Use core::hint::black_box to ensure that the
functions are not optimized out. Also, run these integration tests
in CI to ensure that we don't regress.
Trampoline cargo-in-cargo stdio through cargo:warning to ensure the user
sees all the output.
Use bpf-linker from git in CI so we can see what's going on there.
Remove the manual dependency tracking machinery in
integration-test/build.rs in favor of a build-dependency on
integration-ebpf. This required adding an empty lib.rs to create the
library target.
This allows integration-test/build.rs to be ignorant of bpf-linker.
Remove that in favor of the logic now in integration-ebpf.
Extract the symlink-to-bpf-linker logic from integration-test to xtask
and use it in a new build script in integration-ebpf, causing ebpf
probes to be rebuilt when bpf-linker changes. Previously bpf-linker
changes would rebuild integration-test, but not integration-ebpf,
resulting in stale tests.
Note that this still doesn't address the possibility that a new
bpf-linker is added to the PATH ahead of the cached one. Solving this in
the general case would require rebuild-if-changed-env=PATH *and*
rebuild-if-changed={every-directory-in-PATH} which would likely mean far
too much cache invalidation.
The ebpf probes require a nightly compiler. Before this change, if you
ran `cargo xtask integration-test` with a stable compiler toolchain as
default, or you ran `cargo +stable xtask integration-test`, you would
have seen an error like the one below. This is now fixed by running the
cargo build command in the integration-ebpf directory and making sure
to clear the RUSTUP_TOOLCHAIN env var.
```
--- stderr
/home/ajwerner/src/github.com/aya-rs/aya/test/integration-test/bpf/ring_buf_sched_tracepoint.bpf.c:18:21: warning: declaration of 'struct switch_args' will not be visible outside of this function [-Wvisibility]
int bpf_prog(struct switch_args* ctx)
^
1 warning generated.
error: the `-Z` flag is only accepted on the nightly channel of Cargo, but this is the `stable` channel
See https://doc.rust-lang.org/book/appendix-07-nightly-rust.html for more information about Rust release channels.
thread 'main' panicked at '"cargo" "build" "-p" "integration-ebpf" "-Z" "build-std=core" "--release" "--message-format=json" "--target" "bpfel-unknown-none" "--target-dir" "/home/ajwerner/src/github.com/aya-rs/aya/target/debug/build/integration-test-9bbcb3db5e9f8f57/out/integration-ebpf" exited
with status code 101:
', test/integration-test/build.rs:219:25
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Error: error while building userspace application
Caused by:
Child { stdin: None, stdout: None, stderr: None, .. } exited with status code 101:
```
Libbpf is used by xtasks, in the command, ensure that the submodules
are initialized. This eases the user-experience so that users don't
need to think about the submodule, while retaining all the benefits
of using a submodule vs forcing the user to manually check out libbpf
and stick it in some pre-defined place.
We use the symbol pointing to libbpf in xtask in the build script
to avoid repeating this constant.
Also, we install git in the vm so that we can init the submodule
when we build in the vm.
Emit "cargo:rerun-if-changed={}" for each transitive dependency on
integration-ebpf. In a normal world we'd just add integration-ebpf to
our build-dependencies, but cargo ignores this because integration-ebpf
has no library targets.
The matches crate has been archived now that `matches!` is in std.
However `assert_matches!` is still unstable in std, and the
assert_matches crate provides a more expressive form:
```
assert_matches!(foo, Ok(bar) => {
assert_eq!(bar, baz);
});
```
Tuetuopay
Tamir Duberstein
Andrew Stoycos
Dave Tucker
Andrew Werner
vadorovsky