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feat(aya): Add SchedClassifier:query_tcx() API
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This adds SchedClassifier::query_tcx() API that is able to return an
ordered list of ProgramInfo (and revision) of an interface that has
TCX programs attached.

This is useful to verify the ordering of the programs in our integration
tests, but also to for #1032.

Additionally tidies up the macro used for TCX testing and adds
assertions using this new API.

Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
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dave-tucker committed Sep 19, 2024
1 parent f5d4fde commit 920167c
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Showing 7 changed files with 164 additions and 119 deletions.
9 changes: 7 additions & 2 deletions aya/src/programs/cgroup_device.rs
Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,7 @@ use crate::{
bpf_prog_get_fd_by_id, define_link_wrapper, load_program, query, CgroupAttachMode, FdLink,
Link, ProgAttachLink, ProgramData, ProgramError, ProgramFd,
},
sys::{bpf_link_create, LinkTarget, SyscallError},
sys::{bpf_link_create, LinkTarget, ProgQueryTarget, SyscallError},
util::KernelVersion,
};

Expand Down Expand Up @@ -120,7 +120,12 @@ impl CgroupDevice {
/// Queries the cgroup for attached programs.
pub fn query<T: AsFd>(target_fd: T) -> Result<Vec<CgroupDeviceLink>, ProgramError> {
let target_fd = target_fd.as_fd();
let prog_ids = query(target_fd, BPF_CGROUP_DEVICE, 0, &mut None)?;
let (_, prog_ids) = query(
ProgQueryTarget::Fd(target_fd),
BPF_CGROUP_DEVICE,
0,
&mut None,
)?;

prog_ids
.into_iter()
Expand Down
4 changes: 2 additions & 2 deletions aya/src/programs/lirc_mode2.rs
Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@ use crate::{
load_program, query, CgroupAttachMode, Link, ProgramData, ProgramError, ProgramFd,
ProgramInfo,
},
sys::{bpf_prog_attach, bpf_prog_detach, bpf_prog_get_fd_by_id},
sys::{bpf_prog_attach, bpf_prog_detach, bpf_prog_get_fd_by_id, ProgQueryTarget},
};

/// A program used to decode IR into key events for a lirc device.
Expand Down Expand Up @@ -100,7 +100,7 @@ impl LircMode2 {
/// Queries the lirc device for attached programs.
pub fn query<T: AsFd>(target_fd: T) -> Result<Vec<LircLink>, ProgramError> {
let target_fd = target_fd.as_fd();
let prog_ids = query(target_fd, BPF_LIRC_MODE2, 0, &mut None)?;
let (_, prog_ids) = query(ProgQueryTarget::Fd(target_fd), BPF_LIRC_MODE2, 0, &mut None)?;

prog_ids
.into_iter()
Expand Down
14 changes: 8 additions & 6 deletions aya/src/programs/mod.rs
Original file line number Diff line number Diff line change
Expand Up @@ -73,7 +73,7 @@ use std::{
ffi::CString,
io,
num::TryFromIntError,
os::fd::{AsFd, AsRawFd, BorrowedFd},
os::fd::{AsFd, BorrowedFd},
path::{Path, PathBuf},
sync::Arc,
};
Expand Down Expand Up @@ -122,7 +122,7 @@ use crate::{
sys::{
bpf_btf_get_fd_by_id, bpf_get_object, bpf_link_get_fd_by_id, bpf_link_get_info_by_fd,
bpf_load_program, bpf_pin_object, bpf_prog_get_fd_by_id, bpf_prog_query, iter_link_ids,
retry_with_verifier_logs, EbpfLoadProgramAttrs, SyscallError,
retry_with_verifier_logs, EbpfLoadProgramAttrs, ProgQueryTarget, SyscallError,
},
util::KernelVersion,
VerifierLogLevel,
Expand Down Expand Up @@ -688,28 +688,30 @@ fn load_program<T: Link>(
}

pub(crate) fn query(
target_fd: BorrowedFd<'_>,
target: ProgQueryTarget<'_>,
attach_type: bpf_attach_type,
query_flags: u32,
attach_flags: &mut Option<u32>,
) -> Result<Vec<u32>, ProgramError> {
) -> Result<(u64, Vec<u32>), ProgramError> {
let mut prog_ids = vec![0u32; 64];
let mut prog_cnt = prog_ids.len() as u32;
let mut revision = 0;

let mut retries = 0;

loop {
match bpf_prog_query(
target_fd.as_fd().as_raw_fd(),
&target,
attach_type,
query_flags,
attach_flags.as_mut(),
&mut prog_ids,
&mut prog_cnt,
&mut revision,
) {
Ok(_) => {
prog_ids.resize(prog_cnt as usize, 0);
return Ok(prog_ids);
return Ok((revision, prog_ids));
}
Err((_, io_error)) => {
if retries == 0 && io_error.raw_os_error() == Some(ENOSPC) {
Expand Down
51 changes: 46 additions & 5 deletions aya/src/programs/tc.rs
Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,7 @@ use std::{

use thiserror::Error;

use super::FdLink;
use super::{FdLink, ProgramInfo};
use crate::{
generated::{
bpf_attach_type::{self, BPF_TCX_EGRESS, BPF_TCX_INGRESS},
Expand All @@ -17,12 +17,13 @@ use crate::{
TC_H_CLSACT, TC_H_MIN_EGRESS, TC_H_MIN_INGRESS,
},
programs::{
define_link_wrapper, load_program, Link, LinkError, LinkOrder, ProgramData, ProgramError,
define_link_wrapper, load_program, query, Link, LinkError, LinkOrder, ProgramData,
ProgramError,
},
sys::{
bpf_link_create, bpf_link_get_info_by_fd, bpf_link_update, netlink_find_filter_with_name,
netlink_qdisc_add_clsact, netlink_qdisc_attach, netlink_qdisc_detach, LinkTarget,
SyscallError,
bpf_link_create, bpf_link_get_info_by_fd, bpf_link_update, bpf_prog_get_fd_by_id,
netlink_find_filter_with_name, netlink_qdisc_add_clsact, netlink_qdisc_attach,
netlink_qdisc_detach, LinkTarget, ProgQueryTarget, SyscallError,
},
util::{ifindex_from_ifname, tc_handler_make, KernelVersion},
VerifierLogLevel,
Expand Down Expand Up @@ -340,6 +341,46 @@ impl SchedClassifier {
let data = ProgramData::from_pinned_path(path, VerifierLogLevel::default())?;
Ok(Self { data })
}

/// Queries a given interface for attached TCX programs.
///
/// # Example
///
/// ```no_run
/// # use aya::programs::tc::{TcAttachType, SchedClassifier};
/// # #[derive(Debug, thiserror::Error)]
/// # enum Error {
/// # #[error(transparent)]
/// # Program(#[from] aya::programs::ProgramError),
/// # }
/// let (revision, programs) = SchedClassifier::query_tcx("eth0", TcAttachType::Ingress)?;
/// # Ok::<(), Error>(())
/// ```
pub fn query_tcx(
interface: &str,
attach_type: TcAttachType,
) -> Result<(u64, Vec<ProgramInfo>), ProgramError> {
let if_index = ifindex_from_ifname(interface)
.map_err(|io_error| TcError::NetlinkError { io_error })?;

let (revision, prog_ids) = query(
ProgQueryTarget::IfIndex(if_index),
attach_type.tcx_attach_type()?,
0,
&mut None,
)?;

let prog_infos = prog_ids
.into_iter()
.map(|prog_id| {
let prog_fd = bpf_prog_get_fd_by_id(prog_id)?;
let prog_info = ProgramInfo::new_from_fd(prog_fd.as_fd())?;
Ok::<ProgramInfo, ProgramError>(prog_info)
})
.collect::<Result<_, _>>()?;

Ok((revision, prog_infos))
}
}

#[derive(Debug, Hash, Eq, PartialEq)]
Expand Down
20 changes: 17 additions & 3 deletions aya/src/sys/bpf.rs
Original file line number Diff line number Diff line change
Expand Up @@ -498,25 +498,39 @@ pub(crate) fn bpf_prog_detach(
Ok(())
}

#[derive(Debug, Clone)]
pub(crate) enum ProgQueryTarget<'a> {
Fd(BorrowedFd<'a>),
IfIndex(u32),
}

pub(crate) fn bpf_prog_query(
target_fd: RawFd,
target: &ProgQueryTarget<'_>,
attach_type: bpf_attach_type,
query_flags: u32,
attach_flags: Option<&mut u32>,
prog_ids: &mut [u32],
prog_cnt: &mut u32,
revision: &mut u64,
) -> SysResult<i64> {
let mut attr = unsafe { mem::zeroed::<bpf_attr>() };

attr.query.__bindgen_anon_1.target_fd = target_fd as u32;
match target {
ProgQueryTarget::Fd(fd) => {
attr.query.__bindgen_anon_1.target_fd = fd.as_raw_fd() as u32;
}
ProgQueryTarget::IfIndex(ifindex) => {
attr.query.__bindgen_anon_1.target_ifindex = *ifindex;
}
}
attr.query.attach_type = attach_type as u32;
attr.query.query_flags = query_flags;
attr.query.__bindgen_anon_2.prog_cnt = prog_ids.len() as u32;
attr.query.prog_ids = prog_ids.as_mut_ptr() as u64;

let ret = sys_bpf(bpf_cmd::BPF_PROG_QUERY, &mut attr);

*prog_cnt = unsafe { attr.query.__bindgen_anon_2.prog_cnt };
*revision = unsafe { attr.query.revision };

if let Some(attach_flags) = attach_flags {
*attach_flags = unsafe { attr.query.attach_flags };
Expand Down
Empty file removed macro.patch
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