This allows for Extension programs already loaded to the kernel to be
attached to another program that is BTF-compatible with the one provided
at `load()` time
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
This removes the ProgramFd trait with a struct that wraps a RawFd.
Program::fd() has been implemented as well as fd() for each Program
Type. This allows for a better API than requiring the use of the
ProgramFd trait.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
bpf_map_update_elem is used in lieu of bpf_map_push_elem to maintain support for kernel version < 4.20. The kernel expects a null pointer for the key for this use case. With this change, if you pass None as key to `bpf_map_update_elem`, it will pass null as key.
Files changed:\nM aya/src/generated/linux_bindings_aarch64.rs
M aya/src/generated/linux_bindings_armv7.rs
M aya/src/generated/linux_bindings_riscv64.rs
M aya/src/generated/linux_bindings_x86_64.rs
This allows access to XdpLink, XdpLinkId etc... which is currently
unavailable since these modules are private
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
Files changed:\nM aya/src/generated/linux_bindings_riscv64.rs
M bpf/aya-bpf-bindings/src/riscv64/bindings.rs
M bpf/aya-bpf-bindings/src/riscv64/getters.rs
M bpf/aya-bpf-bindings/src/riscv64/helpers.rs
Files changed:\nM aya/src/generated/linux_bindings_aarch64.rs
M aya/src/generated/linux_bindings_armv7.rs
M aya/src/generated/linux_bindings_x86_64.rs
M bpf/aya-bpf-bindings/src/aarch64/bindings.rs
M bpf/aya-bpf-bindings/src/aarch64/getters.rs
M bpf/aya-bpf-bindings/src/aarch64/helpers.rs
M bpf/aya-bpf-bindings/src/armv7/bindings.rs
M bpf/aya-bpf-bindings/src/armv7/getters.rs
M bpf/aya-bpf-bindings/src/armv7/helpers.rs
M bpf/aya-bpf-bindings/src/x86_64/bindings.rs
M bpf/aya-bpf-bindings/src/x86_64/getters.rs
M bpf/aya-bpf-bindings/src/x86_64/helpers.rs
Since we support multiple maps in the same section, the section_index is
no longer a unique way to identify maps. This commit uses the symbol
index as the identifier, but falls back to section_index for rodata
and bss maps since we don't retrieve the symbol_index during parsing.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
Files changed:\nM aya/src/generated/linux_bindings_aarch64.rs
M aya/src/generated/linux_bindings_armv7.rs
M aya/src/generated/linux_bindings_x86_64.rs
M bpf/aya-bpf-bindings/src/aarch64/bindings.rs
M bpf/aya-bpf-bindings/src/aarch64/getters.rs
M bpf/aya-bpf-bindings/src/aarch64/helpers.rs
M bpf/aya-bpf-bindings/src/armv7/bindings.rs
M bpf/aya-bpf-bindings/src/armv7/getters.rs
M bpf/aya-bpf-bindings/src/armv7/helpers.rs
M bpf/aya-bpf-bindings/src/x86_64/bindings.rs
M bpf/aya-bpf-bindings/src/x86_64/getters.rs
M bpf/aya-bpf-bindings/src/x86_64/helpers.rs
Remove LinkRef and remove the Rc<RefCell<_>> that was used to store
type-erased link values in ProgramData. Among other things, this allows
`Bpf` to be `Send`, which makes it easier to use it with async runtimes.
Change the link API to:
let link_id = prog.attach(...)?;
...
prog.detach(link_id)?;
Link ids are strongly typed, so it's impossible to eg:
let link_id = uprobe.attach(...)?;
xdp.detach(link_id);
As it would result in a compile time error.
Links are still stored inside ProgramData, and unless detached
explicitly, they are automatically detached when the parent program gets
dropped.
This commit uses the symbol table to discover all maps inside an ELF
section. Instead of doing what libbpf does - divide the section data
in to equal sized chunks - we read in to section data using the
symbol address and offset, thus allowing us to support definitions
of varying lengths.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
This changes PerfBuffer::read_events() to call BytesMut::reserve()
internally, and deprecates PerfBufferError::MoreSpaceNeeded.
This makes for a more ergonomic API, and allows for a more idiomatic
usage of BytesMut. For example consider:
let mut buffers = vec![BytesMut::with_capacity(N), ...];
loop {
let events = oob_cpu_buf.read_events(&mut buffers).unwrap();
for buf in &mut buffers[..events.read] {
let sub: Bytes = buf.split_off(n).into();
process_sub_buf(sub);
}
...
}
This is a common way to process perf bufs, where a sub buffer is split
off from the original buffer and then processed. In the next iteration
of the loop when it's time to read again, two things can happen:
- if processing of the sub buffer is complete and `sub` has been
dropped, read_events() will call buf.reserve(sample_size) and hit a fast
path in BytesMut that will just restore the original capacity of the
buffer (assuming sample_size <= N).
- if processing of the sub buffer hasn't ended (eg the buffer has been
stored or is being processed in another thread),
buf.reserve(sample_size) will actually allocate the new memory required
to read the sample.
In other words, calling buf.reserve(sample_size) inside read_events()
simplifies doing zero-copy processing of buffers in many cases.
`BPF_PROG_TYPE_SOCKET_FILTER` program expands the sectionname's kind with `socket` not `socket_filter`.
So current eBPF program with socket filter always fails.
This patch fixes it.
Fix https://github.com/aya-rs/aya/issues/227
fa037a88e2 allowed for cgroup skb programs
that did not specify an attach direction to use the cgroup/skb section
name per the convention established in libbpf. It did not add the
necessary code to load programs from those sections which is added in
this commit
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
Handle relocations against .text symbols in all instructions not just
calls. Makes it so that let x = &some_function triggers linking of
some_function in the current program and handles the resulting
relocation accordingly.
Among other things, enables the use of bpf_for_each_map_elem.
This replaces the / character with a . which is allowed in the kernel
names. Not allowing a forward slash is perhaps a kernel bug, but lets
fix it up here as it's commonly used for Aya
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
Aya will now perform sanitzation and fixups in a single phase, requiring
only one pass over the BTF. This modifies the parsed BTF in place.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
Currently errors can occur if the verifier output is > buffer as we get
ENOMEM. We should only provide a log_buf if initial load failed, then
retry up to 10 times to get full verifier output.
To DRY this logic it has been moved to a function so its shared with
program loading
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
one verifier loop to rule them all
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
If an argument has a type, it must also have a name, see btf_func_check
in the kernel.
Given:
SEC("lsm/syslog")
int BPF_PROG(syslog_audit, int type, int ret_prev)
{
return 0;
}
Fixes:
error: BTF error: the BPF_BTF_LOAD syscall failed. Verifier output: magic: 0xeb9f
version: 1
flags: 0x0
hdr_len: 24
type_off: 0
type_len: 76
str_off: 76
str_len: 128
btf_total_size: 228
[1] FUNC_PROTO (anon) return=2 args=(3 (anon))
[2] INT int size=4 bits_offset=0 nr_bits=32 encoding=SIGNED
[3] PTR (anon) type_id=4
[4] INT long long unsigned int size=8 bits_offset=0 nr_bits=64 encoding=(none)
[5] FUNC syslog_audit type_id=1
[5] FUNC syslog_audit type_id=1 Invalid arg#1
: Invalid argument (os error 22)
The union of `size` and `type` is unused in BTF_KIND_ARRAY.
Type information of elements is in the btf_array struct that follows in
the type_ field while the index type is in the index_type field.
For BTF_KIND_INT, only the offset should be compared and size and
signedness should be ignored.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
This requires loading the BTF to kernel when loading all programs as
well as implementing Extension program type
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
This allows for parsed BTF to be re-encoded such that it could be loaded
in to the kernel. It moves bytes_of to the utils package. We could use
Object::bytes_of, but this requires the impl of the Pod trait on
generated code.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
This commit marks .rodata maps as BPF_F_RDONLY_PROG when loaded to
prevent a BPF program mutating them.
Initial map data is populated by the loader using the new
`BpfLoader::set_global()` API. The loader will mark
is marked as frozen using bpf_map_freeze to prevent map data
being changed from userspace.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
fentry and fexit programs are similar to kprobe and kretprobe, but they
are newer and they have practically zero overhead to call before or
after kernel function. Also, fexit programs are focused on access to
arguments rather than the return value.
Those kind of programs were introduced in the following patchset:
https://lwn.net/Articles/804112/
Signed-off-by: Michal Rostecki <mrostecki@opensuse.org>
Map iteration can yield stale keys and values by virtue of sharing a
data structure with BPF programs which can modify it. However, all
accesses remain perfectly safe and will not cause memory corruption or
data races.
Map and ProgramData objects had unnecessarily cloned strings for their
names, despite them being just as easily available to external users via
bpf.maps() and bpf.programs().
This commit improves section detection.
Previously, a section named "xdp_metadata" would be interpretted as a
program section, which is incorrect. This commit first attempts to
identify a BPF section by name, then by section.kind() ==
SectionKind::Text (executable code). The computed section kind is
stored in the Section so variants can be easily matched on later.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
When a BPF program doesn't specify the target kernel version, the
most compatible option is to set the program kernel version to match
the currently running kernel.
In kernel 4.15 and additional parameter was added to allow maps to have
names but using this breaks on older kernels.
This change makes it so the name is only added on kernels 4.15 and
newer.
This commit fixes name parsing of sk_skb sections such that both named
and unnamed variants will work correctly.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
This change adds support for the following program types:
* raw tracepoint
* LSM
Supporting LSM programs involved a necessity of supporting more
load_attrs for the BPF_PROG_LOAD operation, concretely:
* expected_attach_type - for LSM programs, it has always to be set to
BPF_LSM_MAC
* attach_btf_obj_fd - it's often used to reference the file descriptor of
program's BTF info, altough in case of LSM programs, it only has to
contain the value 0, which means the vmlinux object file (usually
/sys/kernel/btf/vmlinux)
* attach_btf_id - ID of the BTF object, which in case of LSM programs is
the ID of the function (the LSM hook)
The example of LSM program using that functionality can be found here:
https://github.com/vadorovsky/aya-example-lsmFixes: #9
Signed-off-by: William Findlay <william@williamfindlay.com>
Signed-off-by: Michal Rostecki <mrostecki@opensuse.org>
I found a corner case in my own development workflow that caused the existing macro to not
work properly. The following changes appear to fix things. Ideally, we could add some test
cases to CI to prevent regressions. This would require creating a dedicated directory to
hold test cases so that we can "include" them at compile time.
This is a helper macro that can be used to include bytes at compile-time that can then be
used in Bpf::load(). Unlike std's include_bytes!(), this macro also ensures that the
resulting byte array is correctly aligned so that it can be parsed as an ELF binary.
Signed-off-by: William Findlay <william@williamfindlay.com>
This commit adds 2 new methods to aya::sys
- bpf_pin_object
- bpf_get_object
Which allow the pinning and retrieval of programs/maps to bpffs.
It adds a `Program.pin` API, such that a loaded program can be pinned.
For map pinning, the user must ensure the `pinning u32` in the
`bpf_map_def` is set to 1, maps will be pinned using a new builder API.
BpfLoader::new().map_pin_path("/sys/fs/bpf/myapp").load_file("myapp.o")
This will pin all maps whose definition requests pinning to path + name.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
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