Such an assignment in two parts (first deref in `unsafe`, then field
access outside of `unsafe`) is bogus: the deref "returned" by the
`unsafe` block actually creates a copy of the `__sk_buff` struct because
it implements `Copy`. The mark value is written to the `mark` field of
the copy, and not the real `__sk_buff`.
Change it to do it all in the `unsafe` block.
The same is done for the `.len()` getter to avoid copying the whole
`__sk_buff` struct for a 32 bit field. Although such a copy should be
optimized out by the compiler, it's better to help it do so.
Kernel 4.15 added a new eBPF program that can
be used with cgroup v2 to control & observe device
access (e.g. read, write, mknod) - `BPF_PROG_TYPE_CGROUP_DEVICE`.
We add the ability to create these programs with the `cgroup_device`
proc macro which creates the `cgroup/dev` link section. Device
details are available to the eBPF program in `DeviceContext`.
The userspace representation is provided with the `CgroupDevice`
structure.
Fixes: #212
Signed-off-by: Milan <milan@mdaverde.com>
This change separates the previous `SkBuffContext` into three structs:
* `SkBuff` which is a wrapper around `__sk_buff` which contains all
possible methods operating on it.
* `SkBuffContext` which is a program context for programs which
**cannot** access `__sk_buff` directly and instead can only use
`load_bytes`.
* `TcContext` which is a classifier context which can access `__sk_buff`
directly, hence exposes `data` and `data_end`.
Signed-off-by: Michal Rostecki <vadorovsky@gmail.com>
The pull_data method is used to ensure that all the required bytes
are available in the linear portion of the skb.
Signed-off-by: Hengqi Chen <chenhengqi@outlook.com>
The `bpf_printk!` macro is a helper providing a convenient way to invoke the
`bpf_trace_printk` and `bpf_trace_vprintk` BPF helpers. It is implemented as
a macro because it requires variadic arguments.
Change it from `[i8; 16]` to `[u8; 18]`. `i8` arrays cannot be easily used in
Rust for converting to string (i.e. with `core::str::from_utf8_unchecked`)
and developers have to convert them themselves with unsafe code.
Using u8 arrays lets developers to just convert it with
`core::str::from_utf8_unchecked` without any limitations.
Example:
https://github.com/vadorovsky/aya-examples/blob/main/clone/clone-ebpf/src/main.rs
Signed-off-by: Michal Rostecki <vadorovsky@gmail.com>
This change adds two new helpers:
* bpf_probe_read_user_str_bytes
* bpf_probe_read_kernel_str_bytes
Those new helpers are returning a bytes slice (`&[u8]`) with a length
equal to the length of probed, null-terminated string. When using those
helpers, users don't have to manually check for length and create such
slices themselves. They also make converting to `str` way more
convenient, for example:
```rust
let my_str = unsafe {
core::str::from_utf8_unchecked(
bpf_probe_read_user_str_bytes(user_ptr, &mut buf)?
)
};
```
This change also deprecates the old helpers, since their names are
confusing (they have nothing to do with Rust `str`) and using them
requires writing boilerplate code (for checking the length and making
eBPF verifier happy):
* bpf_probe_read_user_str
* bpf_probe_read_kernel_str
Tested on:
516b29af68
Signed-off-by: Michal Rostecki <vadorovsky@gmail.com>
As it turns out, the verifier gets upset if you try to read the values
directly without using bpf_probe_read.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
The bpf_map_defs are now wrapped with UnsafeCell, which also happens to
provide a cozy way to get a *mut pointer. An UnsafeCell isn't strictly
required as the struct fields are practically opaque to us, but using an
UnsafeCell follows the general best practices against miscompilation and
also prevents some obvious errors.
HashMap::get_mut was removed because the idea is completely unsound.
Previous users should wrap their data with UnsafeCell instead or use
atomics.
Closes: https://github.com/aya-rs/aya/issues/233
Currently BPF_MAP_TYPE_STACK is supported by user code (`aya/src/maps/stack.rs`),
but it does not support the BPF_MAP_TYPE_STACK BPF code.
This patch fixes it.
This adds a portable wrapper around pt_regs and user_pt_regs.
It makes writing Raw Tracepoint or KProbe programs easier when the
arguments are one of these types while also ensuring code is portable
across architectures
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
Before this change, documentation of helper functions (defined by us,
not bindings) were not visible, because `use gen::*` was overriding them
with helpers coming from aya-bpf-bindings, which have the same names and
no docs.
Signed-off-by: Michal Rostecki <vadorovsky@gmail.com>
Alessandro Decina
Michal Rostecki
Tuetuopay
Milan
tiann
Ricky Han
abhijeetbhagat
Hengqi Chen
Gabi
Dave Tucker
Joel Höner
Johannes Edmeier
tirex
Tatsuyuki Ishi
Kenjiro Nakayama