From d9c368c2f0f87798b620d95e790ca1df26501d3a Mon Sep 17 00:00:00 2001 From: Tyrone Wu Date: Sat, 19 Oct 2024 18:39:16 +0000 Subject: [PATCH 1/4] aya,aya-obj: add feature probing program type Adds API that probes whether kernel supports a program type. --- Cargo.toml | 1 + aya/src/sys/bpf.rs | 42 +++- aya/src/sys/feature_probe.rs | 98 ++++++++ aya/src/sys/mod.rs | 1 + test/integration-test/Cargo.toml | 1 + test/integration-test/src/tests.rs | 1 + .../src/tests/feature_probe.rs | 212 ++++++++++++++++++ test/integration-test/src/tests/load.rs | 2 +- xtask/public-api/aya.txt | 2 + 9 files changed, 351 insertions(+), 9 deletions(-) create mode 100644 aya/src/sys/feature_probe.rs create mode 100644 test/integration-test/src/tests/feature_probe.rs diff --git a/Cargo.toml b/Cargo.toml index b21d6f34..e95a24ef 100644 --- a/Cargo.toml +++ b/Cargo.toml @@ -87,6 +87,7 @@ octorust = { version = "0.10", default-features = false } once_cell = { version = "1.20.1", default-features = false } proc-macro2 = { version = "1", default-features = false } proc-macro2-diagnostics = { version = "0.10.1", default-features = false } +procfs = { version = "0.17.0", default-features = false } public-api = { version = "0.44.0", default-features = false } quote = { version = "1", default-features = false } rand = { version = "0.9", default-features = false } diff --git a/aya/src/sys/bpf.rs b/aya/src/sys/bpf.rs index 3d6d419f..a52164ed 100644 --- a/aya/src/sys/bpf.rs +++ b/aya/src/sys/bpf.rs @@ -27,7 +27,7 @@ use libc::{ENOENT, ENOSPC}; use crate::{ Btf, FEATURES, Pod, VerifierLogLevel, maps::{MapData, PerCpuValues}, - programs::links::LinkRef, + programs::{ProgramType, links::LinkRef}, sys::{Syscall, SyscallError, syscall}, util::KernelVersion, }; @@ -706,7 +706,7 @@ pub(crate) fn bpf_btf_get_fd_by_id(id: u32) -> Result bool { - with_trivial_prog(|attr| { + with_trivial_prog(ProgramType::TracePoint, |attr| { let u = unsafe { &mut attr.__bindgen_anon_3 }; let name = c"aya_name_check"; let name_bytes = name.to_bytes(); @@ -727,7 +727,7 @@ fn new_insn(code: u8, dst_reg: u8, src_reg: u8, offset: i16, imm: i32) -> bpf_in insn } -fn with_trivial_prog(op: F) -> T +pub(super) fn with_trivial_prog(program_type: ProgramType, op: F) -> T where F: FnOnce(&mut bpf_attr) -> T, { @@ -743,14 +743,40 @@ where u.insn_cnt = insns.len() as u32; u.insns = insns.as_ptr() as u64; - u.prog_type = bpf_prog_type::BPF_PROG_TYPE_TRACEPOINT as u32; + + // `bpf_prog_load_fixup_attach_type()` sets this for us for cgroup_sock and + // and sk_reuseport. + let expected_attach_type = match program_type { + ProgramType::CgroupSkb => Some(bpf_attach_type::BPF_CGROUP_INET_INGRESS), + ProgramType::CgroupSockAddr => Some(bpf_attach_type::BPF_CGROUP_INET4_BIND), + ProgramType::LircMode2 => Some(bpf_attach_type::BPF_LIRC_MODE2), + ProgramType::CgroupSockopt => Some(bpf_attach_type::BPF_CGROUP_GETSOCKOPT), + ProgramType::Tracing => Some(bpf_attach_type::BPF_TRACE_FENTRY), + ProgramType::Lsm => Some(bpf_attach_type::BPF_LSM_MAC), + ProgramType::SkLookup => Some(bpf_attach_type::BPF_SK_LOOKUP), + ProgramType::Netfilter => Some(bpf_attach_type::BPF_NETFILTER), + _ => None, + }; + + match program_type { + ProgramType::KProbe if KernelVersion::current().is_ok() => { + u.kern_version = KernelVersion::current().unwrap().code() + } + ProgramType::Syscall => u.prog_flags = aya_obj::generated::BPF_F_SLEEPABLE, + _ => {} + } + + u.prog_type = program_type as u32; + if let Some(expected_attach_type) = expected_attach_type { + u.expected_attach_type = expected_attach_type as u32; + } op(&mut attr) } /// Tests whether `nr_map_ids` & `map_ids` fields in `bpf_prog_info` is available. pub(crate) fn is_info_map_ids_supported() -> bool { - with_trivial_prog(|attr| { + with_trivial_prog(ProgramType::TracePoint, |attr| { let prog_fd = match bpf_prog_load(attr) { Ok(fd) => fd, Err(_) => return false, @@ -764,7 +790,7 @@ pub(crate) fn is_info_map_ids_supported() -> bool { /// Tests whether `gpl_compatible` field in `bpf_prog_info` is available. pub(crate) fn is_info_gpl_compatible_supported() -> bool { - with_trivial_prog(|attr| { + with_trivial_prog(ProgramType::TracePoint, |attr| { let prog_fd = match bpf_prog_load(attr) { Ok(fd) => fd, Err(_) => return false, @@ -805,7 +831,7 @@ pub(crate) fn is_probe_read_kernel_supported() -> bool { } pub(crate) fn is_perf_link_supported() -> bool { - with_trivial_prog(|attr| { + with_trivial_prog(ProgramType::TracePoint, |attr| { if let Ok(fd) = bpf_prog_load(attr) { let fd = fd.as_fd(); // Uses an invalid target FD so we get EBADF if supported. @@ -1073,7 +1099,7 @@ pub(crate) fn is_btf_type_tag_supported() -> bool { bpf_load_btf(btf_bytes.as_slice(), &mut [], Default::default()).is_ok() } -fn bpf_prog_load(attr: &mut bpf_attr) -> io::Result { +pub(super) fn bpf_prog_load(attr: &mut bpf_attr) -> io::Result { // SAFETY: BPF_PROG_LOAD returns a new file descriptor. unsafe { fd_sys_bpf(bpf_cmd::BPF_PROG_LOAD, attr) } } diff --git a/aya/src/sys/feature_probe.rs b/aya/src/sys/feature_probe.rs new file mode 100644 index 00000000..e60ecd28 --- /dev/null +++ b/aya/src/sys/feature_probe.rs @@ -0,0 +1,98 @@ +//! Probes and identifies available eBPF features supported by the host kernel. + +use aya_obj::btf::{Btf, BtfKind}; +use libc::{E2BIG, EINVAL}; + +use super::{SyscallError, bpf_prog_load, with_trivial_prog}; +use crate::programs::{ProgramError, ProgramType}; + +/// Whether the host kernel supports the [`ProgramType`]. +/// +/// # Examples +/// +/// ```no_run +/// # use aya::{ +/// # programs::ProgramType, +/// # sys::feature_probe::is_program_supported, +/// # }; +/// # +/// match is_program_supported(ProgramType::Xdp) { +/// Ok(true) => println!("XDP supported :)"), +/// Ok(false) => println!("XDP not supported :("), +/// Err(err) => println!("Uh oh! Unexpected error: {:?}", err), +/// } +/// ``` +/// +/// # Errors +/// +/// Returns [`ProgramError::SyscallError`] if a syscall fails with an unexpected +/// error, or [`ProgramError::Btf`] for BTF related errors. +/// +/// Certain errors are expected and handled internally; only unanticipated +/// failures during probing will result in these errors. +pub fn is_program_supported(program_type: ProgramType) -> Result { + if program_type == ProgramType::Unspecified { + return Ok(false); + } + + let mut verifier_log = [0_u8; libc::PATH_MAX as usize]; + let attach_btf_id = if matches!(program_type, ProgramType::Tracing | ProgramType::Lsm) { + let func_name = if program_type == ProgramType::Tracing { + "bpf_fentry_test1" + } else { + "bpf_lsm_bpf" + }; + Btf::from_sys_fs() + .and_then(|btf| btf.id_by_type_name_kind(func_name, BtfKind::Func)) + .unwrap_or(0) + } else { + 0 + }; + + let error = match with_trivial_prog(program_type, |attr| { + // SAFETY: union access + let u = unsafe { &mut attr.__bindgen_anon_3 }; + + u.attach_btf_id = attach_btf_id; + match program_type { + ProgramType::Tracing | ProgramType::Extension | ProgramType::Lsm => { + u.log_buf = verifier_log.as_mut_ptr() as u64; + u.log_level = 1; + u.log_size = verifier_log.len() as u32; + } + _ => {} + } + + bpf_prog_load(attr).err().map(|io_error| { + ProgramError::SyscallError(SyscallError { + call: "bpf_prog_load", + io_error, + }) + }) + }) { + Some(err) => err, + None => return Ok(true), + }; + + match &error { + ProgramError::SyscallError(err) => { + match err.io_error.raw_os_error() { + Some(EINVAL) => { + // verifier/`bpf_check_attach_target()` (or `check_attach_btf_id()` on older + // kernels) produces this log message for these prog types if `attach_btf_id` + // is unset + let supported = matches!( + program_type, + ProgramType::Tracing | ProgramType::Extension | ProgramType::Lsm + if verifier_log.starts_with(b"Tracing programs must provide btf_id")); + Ok(supported) + } + Some(E2BIG) => Ok(false), + // `ENOTSUPP` from verifier/`check_struct_ops_btf_id()` for struct_ops + Some(524) if program_type == ProgramType::StructOps => Ok(true), + _ => Err(error), + } + } + _ => Err(error), + } +} diff --git a/aya/src/sys/mod.rs b/aya/src/sys/mod.rs index f8c8944b..00d3fbdd 100644 --- a/aya/src/sys/mod.rs +++ b/aya/src/sys/mod.rs @@ -1,6 +1,7 @@ //! A collection of system calls for performing eBPF related operations. mod bpf; +pub mod feature_probe; mod netlink; mod perf_event; diff --git a/test/integration-test/Cargo.toml b/test/integration-test/Cargo.toml index 162fc82c..f908c4ea 100644 --- a/test/integration-test/Cargo.toml +++ b/test/integration-test/Cargo.toml @@ -27,6 +27,7 @@ libc = { workspace = true } log = { workspace = true } netns-rs = { workspace = true } object = { workspace = true, features = ["elf", "read_core", "std"] } +procfs = { workspace = true, features = ["flate2"] } rand = { workspace = true, features = ["thread_rng"] } rbpf = { workspace = true } scopeguard = { workspace = true } diff --git a/test/integration-test/src/tests.rs b/test/integration-test/src/tests.rs index 9ca83669..43894366 100644 --- a/test/integration-test/src/tests.rs +++ b/test/integration-test/src/tests.rs @@ -1,6 +1,7 @@ mod bpf_probe_read; mod btf_relocations; mod elf; +mod feature_probe; mod info; mod iter; mod load; diff --git a/test/integration-test/src/tests/feature_probe.rs b/test/integration-test/src/tests/feature_probe.rs new file mode 100644 index 00000000..c1bd0d50 --- /dev/null +++ b/test/integration-test/src/tests/feature_probe.rs @@ -0,0 +1,212 @@ +//! Test feature probing against kernel version. + +use assert_matches::assert_matches; +use aya::{Btf, programs::ProgramType, sys::feature_probe::*, util::KernelVersion}; +use procfs::kernel_config; + +#[test] +fn probe_supported_programs() { + let current = KernelVersion::current().unwrap(); + let kernel_config = kernel_config().unwrap_or_default(); + + let socket_filter = is_program_supported(ProgramType::SocketFilter); + if current >= KernelVersion::new(3, 19, 0) { + assert_matches!(socket_filter, Ok(true)); + } else { + assert_matches!(socket_filter, Ok(false)); + } + + let kprobe = is_program_supported(ProgramType::KProbe); + let sched_cls = is_program_supported(ProgramType::SchedClassifier); + let sched_act = is_program_supported(ProgramType::SchedAction); + if current >= KernelVersion::new(4, 1, 0) { + assert_matches!(kprobe, Ok(true)); + assert_matches!(sched_cls, Ok(true)); + assert_matches!(sched_act, Ok(true)); + } else { + assert_matches!(kprobe, Ok(false)); + assert_matches!(sched_cls, Ok(false)); + assert_matches!(sched_act, Ok(false)); + } + + let tracepoint = is_program_supported(ProgramType::TracePoint); + if current >= KernelVersion::new(4, 7, 0) { + assert_matches!(tracepoint, Ok(true)); + } else { + assert_matches!(tracepoint, Ok(false)); + } + + let xdp = is_program_supported(ProgramType::Xdp); + if current >= KernelVersion::new(4, 8, 0) { + assert_matches!(xdp, Ok(true)); + } else { + assert_matches!(xdp, Ok(false)); + } + + let perf_event = is_program_supported(ProgramType::PerfEvent); + if current >= KernelVersion::new(4, 9, 0) { + assert_matches!(perf_event, Ok(true)); + } else { + assert_matches!(perf_event, Ok(false)); + } + + let cgroup_skb = is_program_supported(ProgramType::CgroupSkb); + let cgroup_sock = is_program_supported(ProgramType::CgroupSock); + let lwt_in = is_program_supported(ProgramType::LwtInput); + let lwt_out = is_program_supported(ProgramType::LwtOutput); + let lwt_xmit = is_program_supported(ProgramType::LwtXmit); + if current >= KernelVersion::new(4, 10, 0) { + assert_matches!(cgroup_skb, Ok(true)); + assert_matches!(cgroup_sock, Ok(true)); + assert_matches!(lwt_in, Ok(true)); + assert_matches!(lwt_out, Ok(true)); + assert_matches!(lwt_xmit, Ok(true)); + } else { + assert_matches!(cgroup_skb, Ok(false)); + assert_matches!(cgroup_sock, Ok(false)); + assert_matches!(lwt_in, Ok(false)); + assert_matches!(lwt_out, Ok(false)); + assert_matches!(lwt_xmit, Ok(false)); + } + + let sock_ops = is_program_supported(ProgramType::SockOps); + if current >= KernelVersion::new(4, 13, 0) { + assert_matches!(sock_ops, Ok(true)); + } else { + assert_matches!(sock_ops, Ok(false)); + } + + let sk_skb = is_program_supported(ProgramType::SkSkb); + if current >= KernelVersion::new(4, 14, 0) { + assert_matches!(sk_skb, Ok(true)); + } else { + assert_matches!(sk_skb, Ok(false)); + } + + let cgroup_device = is_program_supported(ProgramType::CgroupDevice); + if current >= KernelVersion::new(4, 15, 0) { + assert_matches!(cgroup_device, Ok(true)); + } else { + assert_matches!(cgroup_device, Ok(false)); + } + + let sk_msg = is_program_supported(ProgramType::SkMsg); + let raw_tp = is_program_supported(ProgramType::RawTracePoint); + let cgroup_sock_addr = is_program_supported(ProgramType::CgroupSockAddr); + if current >= KernelVersion::new(4, 17, 0) { + assert_matches!(sk_msg, Ok(true)); + assert_matches!(raw_tp, Ok(true)); + assert_matches!(cgroup_sock_addr, Ok(true)); + } else { + assert_matches!(sk_msg, Ok(false)); + assert_matches!(raw_tp, Ok(false)); + assert_matches!(cgroup_sock_addr, Ok(false)); + } + + let lwt_seg6local = is_program_supported(ProgramType::LwtSeg6local); + let lirc_mode2 = is_program_supported(ProgramType::LircMode2); // Requires CONFIG_BPF_LIRC_MODE2=y + if current >= KernelVersion::new(4, 18, 0) { + assert_matches!(lwt_seg6local, Ok(true)); + + let lirc_mode2_config = matches!( + kernel_config.get("CONFIG_BPF_LIRC_MODE2"), + Some(procfs::ConfigSetting::Yes) + ); + assert_matches!(lirc_mode2, Ok(lirc_mode2) if lirc_mode2 == lirc_mode2_config); + if !lirc_mode2_config { + eprintln!("CONFIG_BPF_LIRC_MODE2 required for lirc_mode2 program type"); + } + } else { + assert_matches!(lwt_seg6local, Ok(false)); + assert_matches!(lirc_mode2, Ok(false)); + } + + let sk_reuseport = is_program_supported(ProgramType::SkReuseport); + if current >= KernelVersion::new(4, 19, 0) { + assert_matches!(sk_reuseport, Ok(true)); + } else { + assert_matches!(sk_reuseport, Ok(false)); + } + + let flow_dissector = is_program_supported(ProgramType::FlowDissector); + if current >= KernelVersion::new(4, 20, 0) { + assert_matches!(flow_dissector, Ok(true)); + } else { + assert_matches!(flow_dissector, Ok(false)); + } + + let cgroup_sysctl = is_program_supported(ProgramType::CgroupSysctl); + let raw_tp_writable = is_program_supported(ProgramType::RawTracePointWritable); + if current >= KernelVersion::new(5, 2, 0) { + assert_matches!(cgroup_sysctl, Ok(true)); + assert_matches!(raw_tp_writable, Ok(true)); + } else { + assert_matches!(cgroup_sysctl, Ok(false)); + assert_matches!(raw_tp_writable, Ok(false)); + } + + let cgroup_sockopt = is_program_supported(ProgramType::CgroupSockopt); + if current >= KernelVersion::new(5, 3, 0) { + assert_matches!(cgroup_sockopt, Ok(true)); + } else { + assert_matches!(cgroup_sockopt, Ok(false)); + } + + let tracing = is_program_supported(ProgramType::Tracing); // Requires `CONFIG_DEBUG_INFO_BTF=y` + if current >= KernelVersion::new(5, 5, 0) { + assert_matches!(tracing, Ok(true)); + } else { + assert_matches!(tracing, Ok(false)); + } + + let struct_ops = is_program_supported(ProgramType::StructOps); + let extension = is_program_supported(ProgramType::Extension); + if current >= KernelVersion::new(5, 6, 0) { + assert_matches!(struct_ops, Ok(true)); + assert_matches!(extension, Ok(true)); + } else { + assert_matches!(struct_ops, Ok(false)); + assert_matches!(extension, Ok(false)); + } + + let lsm = is_program_supported(ProgramType::Lsm); // Requires `CONFIG_DEBUG_INFO_BTF=y` & `CONFIG_BPF_LSM=y` + if current >= KernelVersion::new(5, 7, 0) { + // Ways to check if `CONFIG_BPF_LSM` is enabled: + // - kernel config has `CONFIG_BPF_LSM=y`, but config is not always exposed. + // - an LSM hooks is present in BTF, e.g. `bpf_lsm_bpf`. hooks are found in `bpf_lsm.c` + let lsm_enabled = matches!( + kernel_config.get("CONFIG_BPF_LSM"), + Some(procfs::ConfigSetting::Yes) + ) || Btf::from_sys_fs() + .and_then(|btf| btf.id_by_type_name_kind("bpf_lsm_bpf", aya_obj::btf::BtfKind::Func)) + .is_ok(); + + assert_matches!(lsm, Ok(lsm_supported) if lsm_supported == lsm_enabled); + if !lsm_enabled { + eprintln!("CONFIG_BPF_LSM required for lsm program type"); + } + } else { + assert_matches!(lsm, Ok(false)); + } + + let sk_lookup = is_program_supported(ProgramType::SkLookup); + if current >= KernelVersion::new(5, 9, 0) { + assert_matches!(sk_lookup, Ok(true)); + } else { + assert_matches!(sk_lookup, Ok(false)); + } + + let syscall = is_program_supported(ProgramType::Syscall); + if current >= KernelVersion::new(5, 14, 0) { + assert_matches!(syscall, Ok(true)); + } else { + assert_matches!(syscall, Ok(false)); + } + + let netfilter = is_program_supported(ProgramType::Netfilter); + if current >= KernelVersion::new(6, 4, 0) { + assert_matches!(netfilter, Ok(true)); + } else { + assert_matches!(netfilter, Ok(false)); + } +} diff --git a/test/integration-test/src/tests/load.rs b/test/integration-test/src/tests/load.rs index a93e6f16..85268ab9 100644 --- a/test/integration-test/src/tests/load.rs +++ b/test/integration-test/src/tests/load.rs @@ -14,7 +14,7 @@ use aya_obj::programs::XdpAttachType; use test_log::test; const MAX_RETRIES: usize = 100; -const RETRY_DURATION: Duration = Duration::from_millis(10); +pub(crate) const RETRY_DURATION: Duration = Duration::from_millis(10); #[test] fn long_name() { diff --git a/xtask/public-api/aya.txt b/xtask/public-api/aya.txt index 94a70d3c..92d8ff60 100644 --- a/xtask/public-api/aya.txt +++ b/xtask/public-api/aya.txt @@ -9997,6 +9997,8 @@ impl aya::programs::MultiProgram for aya::programs::tc::SchedClassifier pub fn aya::programs::tc::SchedClassifier::fd(&self) -> core::result::Result, aya::programs::ProgramError> pub fn aya::programs::loaded_programs() -> impl core::iter::traits::iterator::Iterator> pub mod aya::sys +pub mod aya::sys::feature_probe +pub fn aya::sys::feature_probe::is_program_supported(program_type: aya::programs::ProgramType) -> core::result::Result #[non_exhaustive] pub enum aya::sys::Stats pub aya::sys::Stats::RunTime impl core::clone::Clone for aya::sys::Stats From e5e5bfd0747fdb34e519506df7e5808ef9afba67 Mon Sep 17 00:00:00 2001 From: Tyrone Wu Date: Mon, 28 Oct 2024 02:09:27 +0000 Subject: [PATCH 2/4] aya: add feature probing for map type Add API that probes whether kernel supports a map type. --- aya/src/sys/bpf.rs | 5 +- aya/src/sys/feature_probe.rs | 159 +++++++++++++- .../src/tests/feature_probe.rs | 198 +++++++++++++++++- xtask/public-api/aya.txt | 1 + 4 files changed, 357 insertions(+), 6 deletions(-) diff --git a/aya/src/sys/bpf.rs b/aya/src/sys/bpf.rs index a52164ed..f27c32a0 100644 --- a/aya/src/sys/bpf.rs +++ b/aya/src/sys/bpf.rs @@ -681,7 +681,10 @@ pub(crate) fn bpf_load_btf( } // SAFETY: only use for bpf_cmd that return a new file descriptor on success. -unsafe fn fd_sys_bpf(cmd: bpf_cmd, attr: &mut bpf_attr) -> io::Result { +pub(super) unsafe fn fd_sys_bpf( + cmd: bpf_cmd, + attr: &mut bpf_attr, +) -> io::Result { let fd = sys_bpf(cmd, attr)?; let fd = fd.try_into().map_err(|std::num::TryFromIntError { .. }| { io::Error::new( diff --git a/aya/src/sys/feature_probe.rs b/aya/src/sys/feature_probe.rs index e60ecd28..c710a349 100644 --- a/aya/src/sys/feature_probe.rs +++ b/aya/src/sys/feature_probe.rs @@ -1,10 +1,19 @@ //! Probes and identifies available eBPF features supported by the host kernel. -use aya_obj::btf::{Btf, BtfKind}; -use libc::{E2BIG, EINVAL}; +use std::{mem, os::fd::AsRawFd as _}; -use super::{SyscallError, bpf_prog_load, with_trivial_prog}; -use crate::programs::{ProgramError, ProgramType}; +use aya_obj::{ + btf::{Btf, BtfKind}, + generated::{BPF_F_MMAPABLE, BPF_F_NO_PREALLOC, bpf_attr, bpf_cmd, bpf_map_type}, +}; +use libc::{E2BIG, EBADF, EINVAL}; + +use super::{SyscallError, bpf_prog_load, fd_sys_bpf, with_trivial_prog}; +use crate::{ + maps::MapType, + programs::{ProgramError, ProgramType}, + util::page_size, +}; /// Whether the host kernel supports the [`ProgramType`]. /// @@ -96,3 +105,145 @@ pub fn is_program_supported(program_type: ProgramType) -> Result Err(error), } } + +/// Whether the host kernel supports the [`MapType`]. +/// +/// # Examples +/// +/// ```no_run +/// # use aya::{ +/// # maps::MapType, +/// # sys::feature_probe::is_map_supported, +/// # }; +/// # +/// match is_map_supported(MapType::HashOfMaps) { +/// Ok(true) => println!("hash_of_maps supported :)"), +/// Ok(false) => println!("hash_of_maps not supported :("), +/// Err(err) => println!("Uh oh! Unexpected error: {:?}", err), +/// } +/// ``` +/// +/// # Errors +/// +/// Returns [`SyscallError`] if kernel probing fails with an unexpected error. +/// +/// Note that certain errors are expected and handled internally; only +/// unanticipated failures during probing will result in this error. +pub fn is_map_supported(map_type: MapType) -> Result { + if map_type == MapType::Unspecified { + return Ok(false); + } + + // SAFETY: all-zero byte-pattern valid for `bpf_attr` + let mut attr = unsafe { mem::zeroed::() }; + // SAFETY: union access + let u = unsafe { &mut attr.__bindgen_anon_1 }; + + // To pass `map_alloc_check`/`map_alloc` + let key_size = match map_type { + MapType::LpmTrie | MapType::CgroupStorage | MapType::PerCpuCgroupStorage => 16, + MapType::Queue + | MapType::Stack + | MapType::RingBuf + | MapType::BloomFilter + | MapType::UserRingBuf + | MapType::Arena => 0, + _ => 4, + }; + let value_size = match map_type { + MapType::StackTrace | MapType::LpmTrie => 8, + MapType::RingBuf | MapType::UserRingBuf | MapType::Arena => 0, + _ => 4, + }; + let max_entries = match map_type { + MapType::CgroupStorage + | MapType::PerCpuCgroupStorage + | MapType::SkStorage + | MapType::InodeStorage + | MapType::TaskStorage + | MapType::CgrpStorage => 0, + MapType::RingBuf | MapType::UserRingBuf => page_size() as u32, + _ => 1, + }; + + // Ensure that fd doesn't get dropped due to scoping. + let inner_map_fd; + match map_type { + MapType::LpmTrie => u.map_flags = BPF_F_NO_PREALLOC, + MapType::SkStorage + | MapType::InodeStorage + | MapType::TaskStorage + | MapType::CgrpStorage => { + u.map_flags = BPF_F_NO_PREALLOC; + // Intentionally trigger `EBADF` from `btf_get_by_fd()`. + u.btf_fd = u32::MAX; + u.btf_key_type_id = 1; + u.btf_value_type_id = 1; + } + MapType::ArrayOfMaps | MapType::HashOfMaps => { + // SAFETY: all-zero byte-pattern valid for `bpf_attr` + let mut attr_map = unsafe { mem::zeroed::() }; + // SAFETY: union access + let u_map = unsafe { &mut attr_map.__bindgen_anon_1 }; + u_map.map_type = bpf_map_type::BPF_MAP_TYPE_HASH as u32; + u_map.key_size = 1; + u_map.value_size = 1; + u_map.max_entries = 1; + // SAFETY: BPF_MAP_CREATE returns a new file descriptor. + inner_map_fd = unsafe { fd_sys_bpf(bpf_cmd::BPF_MAP_CREATE, &mut attr_map) }.map_err( + |io_error| SyscallError { + call: "bpf_map_create", + io_error, + }, + )?; + + u.inner_map_fd = inner_map_fd.as_raw_fd() as u32; + } + MapType::StructOps => u.btf_vmlinux_value_type_id = 1, + MapType::Arena => u.map_flags = BPF_F_MMAPABLE, + _ => {} + } + + u.map_type = map_type as u32; + u.key_size = key_size; + u.value_size = value_size; + u.max_entries = max_entries; + + // SAFETY: BPF_MAP_CREATE returns a new file descriptor. + let io_error = match unsafe { fd_sys_bpf(bpf_cmd::BPF_MAP_CREATE, &mut attr) } { + Ok(_) => return Ok(true), + Err(io_error) => io_error, + }; + match io_error.raw_os_error() { + Some(EINVAL) => Ok(false), + Some(E2BIG) + if matches!( + map_type, + MapType::SkStorage + | MapType::StructOps + | MapType::InodeStorage + | MapType::TaskStorage + | MapType::CgrpStorage + ) => + { + Ok(false) + } + Some(EBADF) + if matches!( + map_type, + MapType::SkStorage + | MapType::InodeStorage + | MapType::TaskStorage + | MapType::CgrpStorage + ) => + { + Ok(true) + } + // `ENOTSUPP` from `bpf_struct_ops_map_alloc()` for struct_ops. + Some(524) if map_type == MapType::StructOps => Ok(true), + _ => Err(SyscallError { + call: "bpf_map_create", + io_error, + }), + } +} diff --git a/test/integration-test/src/tests/feature_probe.rs b/test/integration-test/src/tests/feature_probe.rs index c1bd0d50..5c57afe3 100644 --- a/test/integration-test/src/tests/feature_probe.rs +++ b/test/integration-test/src/tests/feature_probe.rs @@ -1,7 +1,7 @@ //! Test feature probing against kernel version. use assert_matches::assert_matches; -use aya::{Btf, programs::ProgramType, sys::feature_probe::*, util::KernelVersion}; +use aya::{Btf, maps::MapType, programs::ProgramType, sys::feature_probe::*, util::KernelVersion}; use procfs::kernel_config; #[test] @@ -210,3 +210,199 @@ fn probe_supported_programs() { assert_matches!(netfilter, Ok(false)); } } + +#[test] +fn probe_supported_maps() { + let current = KernelVersion::current().unwrap(); + + let hash = is_map_supported(MapType::Hash); + let array = is_map_supported(MapType::Array); + if current >= KernelVersion::new(3, 19, 0) { + assert_matches!(hash, Ok(true)); + assert_matches!(array, Ok(true)); + } else { + assert_matches!(hash, Ok(false)); + assert_matches!(array, Ok(false)); + } + + let prog_array = is_map_supported(MapType::ProgramArray); + if current >= KernelVersion::new(4, 2, 0) { + assert_matches!(prog_array, Ok(true)); + } else { + assert_matches!(prog_array, Ok(false)); + } + + let perf_event_array = is_map_supported(MapType::PerfEventArray); + if current >= KernelVersion::new(4, 3, 0) { + assert_matches!(perf_event_array, Ok(true)); + } else { + assert_matches!(perf_event_array, Ok(false)); + } + + let per_cpu_hash = is_map_supported(MapType::PerCpuHash); + let per_cpu_array = is_map_supported(MapType::PerCpuArray); + let stack_trace = is_map_supported(MapType::StackTrace); + if current >= KernelVersion::new(4, 6, 0) { + assert_matches!(per_cpu_hash, Ok(true)); + assert_matches!(per_cpu_array, Ok(true)); + assert_matches!(stack_trace, Ok(true)); + } else { + assert_matches!(per_cpu_hash, Ok(false)); + assert_matches!(per_cpu_array, Ok(false)); + assert_matches!(stack_trace, Ok(false)); + } + + let cgroup_array = is_map_supported(MapType::CgroupArray); + if current >= KernelVersion::new(4, 8, 0) { + assert_matches!(cgroup_array, Ok(true)); + } else { + assert_matches!(cgroup_array, Ok(false)); + } + + let lru_hash = is_map_supported(MapType::LruHash); + let lru_per_cpu_hash = is_map_supported(MapType::LruPerCpuHash); + if current >= KernelVersion::new(4, 10, 0) { + assert_matches!(lru_hash, Ok(true)); + assert_matches!(lru_per_cpu_hash, Ok(true)); + } else { + assert_matches!(lru_hash, Ok(false)); + assert_matches!(lru_per_cpu_hash, Ok(false)); + } + + let lpm_trie = is_map_supported(MapType::LpmTrie); + if current >= KernelVersion::new(4, 11, 0) { + assert_matches!(lpm_trie, Ok(true)); + } else { + assert_matches!(lpm_trie, Ok(false)); + } + + let array_of_maps = is_map_supported(MapType::ArrayOfMaps); + let hash_of_maps = is_map_supported(MapType::HashOfMaps); + if current >= KernelVersion::new(4, 12, 0) { + assert_matches!(array_of_maps, Ok(true)); + assert_matches!(hash_of_maps, Ok(true)); + } else { + assert_matches!(array_of_maps, Ok(false)); + assert_matches!(hash_of_maps, Ok(false)); + } + + let dev_map = is_map_supported(MapType::DevMap); + let sock_map = is_map_supported(MapType::SockMap); + if current >= KernelVersion::new(4, 14, 0) { + assert_matches!(dev_map, Ok(true)); + assert_matches!(sock_map, Ok(true)); + } else { + assert_matches!(dev_map, Ok(false)); + assert_matches!(sock_map, Ok(false)); + } + + let cpu_map = is_map_supported(MapType::CpuMap); + if current >= KernelVersion::new(4, 15, 0) { + assert_matches!(cpu_map, Ok(true)); + } else { + assert_matches!(cpu_map, Ok(false)); + } + + let xsk_map = is_map_supported(MapType::XskMap); + let sock_hash = is_map_supported(MapType::SockHash); + if current >= KernelVersion::new(4, 18, 0) { + assert_matches!(xsk_map, Ok(true)); + assert_matches!(sock_hash, Ok(true)); + } else { + assert_matches!(xsk_map, Ok(false)); + assert_matches!(sock_hash, Ok(false)); + } + + let cgroup_storage = is_map_supported(MapType::CgroupStorage); + let reuseport_sock_array = is_map_supported(MapType::ReuseportSockArray); + if current >= KernelVersion::new(4, 19, 0) { + assert_matches!(cgroup_storage, Ok(true)); + assert_matches!(reuseport_sock_array, Ok(true)); + } else { + assert_matches!(cgroup_storage, Ok(false)); + assert_matches!(reuseport_sock_array, Ok(false)); + } + + let per_cpu_cgroup_storage = is_map_supported(MapType::PerCpuCgroupStorage); + let queue = is_map_supported(MapType::Queue); + let stack = is_map_supported(MapType::Stack); + if current >= KernelVersion::new(4, 20, 0) { + assert_matches!(per_cpu_cgroup_storage, Ok(true)); + assert_matches!(queue, Ok(true)); + assert_matches!(stack, Ok(true)); + } else { + assert_matches!(per_cpu_cgroup_storage, Ok(false)); + assert_matches!(queue, Ok(false)); + assert_matches!(stack, Ok(false)); + } + + let sk_storage = is_map_supported(MapType::SkStorage); + if current >= KernelVersion::new(5, 2, 0) { + assert_matches!(sk_storage, Ok(true)); + } else { + assert_matches!(sk_storage, Ok(false)); + } + + let devmap_hash = is_map_supported(MapType::DevMapHash); + if current >= KernelVersion::new(5, 4, 0) { + assert_matches!(devmap_hash, Ok(true)); + } else { + assert_matches!(devmap_hash, Ok(false)); + } + + let struct_ops = is_map_supported(MapType::StructOps); + if current >= KernelVersion::new(5, 6, 0) { + assert_matches!(struct_ops, Ok(true)); + } else { + assert_matches!(struct_ops, Ok(false)); + } + + let ring_buf = is_map_supported(MapType::RingBuf); + if current >= KernelVersion::new(5, 8, 0) { + assert_matches!(ring_buf, Ok(true)); + } else { + assert_matches!(ring_buf, Ok(false)); + } + + let inode_storage = is_map_supported(MapType::InodeStorage); // Requires `CONFIG_BPF_LSM=y` + if current >= KernelVersion::new(5, 10, 0) { + assert_matches!(inode_storage, Ok(true)); + } else { + assert_matches!(inode_storage, Ok(false)); + } + + let task_storage = is_map_supported(MapType::TaskStorage); + if current >= KernelVersion::new(5, 11, 0) { + assert_matches!(task_storage, Ok(true)); + } else { + assert_matches!(task_storage, Ok(false)); + } + + let bloom_filter = is_map_supported(MapType::BloomFilter); + if current >= KernelVersion::new(5, 16, 0) { + assert_matches!(bloom_filter, Ok(true)); + } else { + assert_matches!(bloom_filter, Ok(false)); + } + + let user_ring_buf = is_map_supported(MapType::UserRingBuf); + if current >= KernelVersion::new(6, 1, 0) { + assert_matches!(user_ring_buf, Ok(true)); + } else { + assert_matches!(user_ring_buf, Ok(false)); + } + + let cgrp_storage = is_map_supported(MapType::CgrpStorage); + if current >= KernelVersion::new(6, 2, 0) { + assert_matches!(cgrp_storage, Ok(true)); + } else { + assert_matches!(cgrp_storage, Ok(false)); + } + + let arena = is_map_supported(MapType::Arena); + if current >= KernelVersion::new(6, 9, 0) { + assert_matches!(arena, Ok(true)); + } else { + assert_matches!(arena, Ok(false)); + } +} diff --git a/xtask/public-api/aya.txt b/xtask/public-api/aya.txt index 92d8ff60..8e2c2238 100644 --- a/xtask/public-api/aya.txt +++ b/xtask/public-api/aya.txt @@ -9998,6 +9998,7 @@ pub fn aya::programs::tc::SchedClassifier::fd(&self) -> core::result::Result impl core::iter::traits::iterator::Iterator> pub mod aya::sys pub mod aya::sys::feature_probe +pub fn aya::sys::feature_probe::is_map_supported(map_type: aya::maps::MapType) -> core::result::Result pub fn aya::sys::feature_probe::is_program_supported(program_type: aya::programs::ProgramType) -> core::result::Result #[non_exhaustive] pub enum aya::sys::Stats pub aya::sys::Stats::RunTime From 85d67acb79ea2654d7d2116b7610ce9b5cd57a83 Mon Sep 17 00:00:00 2001 From: Tyrone Wu Date: Mon, 28 Oct 2024 02:12:54 +0000 Subject: [PATCH 3/4] aya,aya-obj: cache feat probed info fields Cached probed for ProgramInfo fields instead of exposing it through global FEATURE. Probing occurs on cache miss, which happens when first accessing the field, *and* if the field is 0. --- aya-obj/src/obj.rs | 16 ------ aya/src/bpf.rs | 8 ++- aya/src/programs/info.rs | 26 ++++++---- aya/src/sys/bpf.rs | 34 ++----------- aya/src/sys/feature_probe.rs | 67 +++++++++++++++++++++++-- test/integration-test/src/tests/info.rs | 60 ++++++++++++++++------ xtask/public-api/aya-obj.txt | 4 -- 7 files changed, 131 insertions(+), 84 deletions(-) diff --git a/aya-obj/src/obj.rs b/aya-obj/src/obj.rs index 871e6937..f06270b5 100644 --- a/aya-obj/src/obj.rs +++ b/aya-obj/src/obj.rs @@ -45,8 +45,6 @@ pub struct Features { bpf_cookie: bool, cpumap_prog_id: bool, devmap_prog_id: bool, - prog_info_map_ids: bool, - prog_info_gpl_compatible: bool, btf: Option, } @@ -61,8 +59,6 @@ impl Features { bpf_cookie: bool, cpumap_prog_id: bool, devmap_prog_id: bool, - prog_info_map_ids: bool, - prog_info_gpl_compatible: bool, btf: Option, ) -> Self { Self { @@ -73,8 +69,6 @@ impl Features { bpf_cookie, cpumap_prog_id, devmap_prog_id, - prog_info_map_ids, - prog_info_gpl_compatible, btf, } } @@ -117,16 +111,6 @@ impl Features { self.devmap_prog_id } - /// Returns whether `bpf_prog_info` supports `nr_map_ids` & `map_ids` fields. - pub fn prog_info_map_ids(&self) -> bool { - self.prog_info_map_ids - } - - /// Returns whether `bpf_prog_info` supports `gpl_compatible` field. - pub fn prog_info_gpl_compatible(&self) -> bool { - self.prog_info_gpl_compatible - } - /// If BTF is supported, returns which BTF features are supported. pub fn btf(&self) -> Option<&BtfFeatures> { self.btf.as_ref() diff --git a/aya/src/bpf.rs b/aya/src/bpf.rs index 9c11defc..18fa60ea 100644 --- a/aya/src/bpf.rs +++ b/aya/src/bpf.rs @@ -32,9 +32,9 @@ use crate::{ bpf_load_btf, is_bpf_cookie_supported, is_bpf_global_data_supported, is_btf_datasec_supported, is_btf_decl_tag_supported, is_btf_enum64_supported, is_btf_float_supported, is_btf_func_global_supported, is_btf_func_supported, - is_btf_supported, is_btf_type_tag_supported, is_info_gpl_compatible_supported, - is_info_map_ids_supported, is_perf_link_supported, is_probe_read_kernel_supported, - is_prog_id_supported, is_prog_name_supported, retry_with_verifier_logs, + is_btf_supported, is_btf_type_tag_supported, is_perf_link_supported, + is_probe_read_kernel_supported, is_prog_id_supported, is_prog_name_supported, + retry_with_verifier_logs, }, util::{bytes_of, bytes_of_slice, nr_cpus, page_size}, }; @@ -82,8 +82,6 @@ fn detect_features() -> Features { is_bpf_cookie_supported(), is_prog_id_supported(BPF_MAP_TYPE_CPUMAP), is_prog_id_supported(BPF_MAP_TYPE_DEVMAP), - is_info_map_ids_supported(), - is_info_gpl_compatible_supported(), btf, ); debug!("BPF Feature Detection: {:#?}", f); diff --git a/aya/src/programs/info.rs b/aya/src/programs/info.rs index 876264d1..753d6054 100644 --- a/aya/src/programs/info.rs +++ b/aya/src/programs/info.rs @@ -4,6 +4,7 @@ use std::{ ffi::CString, os::fd::{AsFd as _, BorrowedFd}, path::Path, + sync::OnceLock, time::{Duration, SystemTime}, }; @@ -16,7 +17,9 @@ use super::{ use crate::{ FEATURES, sys::{ - SyscallError, bpf_get_object, bpf_prog_get_fd_by_id, bpf_prog_get_info_by_fd, iter_prog_ids, + SyscallError, bpf_get_object, bpf_prog_get_fd_by_id, bpf_prog_get_info_by_fd, + feature_probe::{is_prog_info_license_supported, is_prog_info_map_ids_supported}, + iter_prog_ids, }, util::bytes_of_bpf_name, }; @@ -108,13 +111,15 @@ impl ProgramInfo { /// /// Introduced in kernel v4.15. pub fn map_ids(&self) -> Result>, ProgramError> { - if FEATURES.prog_info_map_ids() { - let mut map_ids = vec![0u32; self.0.nr_map_ids as usize]; - bpf_prog_get_info_by_fd(self.fd()?.as_fd(), &mut map_ids)?; - Ok(Some(map_ids)) - } else { - Ok(None) - } + static CACHE: OnceLock = OnceLock::new(); + CACHE + .get_or_init(|| matches!(is_prog_info_map_ids_supported(), Ok(true))) + .then(|| { + let mut map_ids = vec![0u32; self.0.nr_map_ids as usize]; + bpf_prog_get_info_by_fd(self.fd()?.as_fd(), &mut map_ids)?; + Ok(map_ids) + }) + .transpose() } /// The name of the program as was provided when it was load. This is limited to 16 bytes. @@ -140,8 +145,9 @@ impl ProgramInfo { /// /// Introduced in kernel v4.18. pub fn gpl_compatible(&self) -> Option { - FEATURES - .prog_info_gpl_compatible() + static CACHE: OnceLock = OnceLock::new(); + CACHE + .get_or_init(|| matches!(is_prog_info_license_supported(), Ok(true))) .then_some(self.0.gpl_compatible() != 0) } diff --git a/aya/src/sys/bpf.rs b/aya/src/sys/bpf.rs index f27c32a0..078220d6 100644 --- a/aya/src/sys/bpf.rs +++ b/aya/src/sys/bpf.rs @@ -25,7 +25,7 @@ use aya_obj::{ use libc::{ENOENT, ENOSPC}; use crate::{ - Btf, FEATURES, Pod, VerifierLogLevel, + Btf, Pod, VerifierLogLevel, maps::{MapData, PerCpuValues}, programs::{ProgramType, links::LinkRef}, sys::{Syscall, SyscallError, syscall}, @@ -593,7 +593,7 @@ pub(crate) fn bpf_prog_get_info_by_fd( // An `E2BIG` error can occur on kernels below v4.15 when handing over a large struct where the // extra space is not all-zero bytes. bpf_obj_get_info_by_fd(fd, |info: &mut bpf_prog_info| { - if FEATURES.prog_info_map_ids() { + if !map_ids.is_empty() { info.nr_map_ids = map_ids.len() as _; info.map_ids = map_ids.as_mut_ptr() as _; } @@ -777,34 +777,6 @@ where op(&mut attr) } -/// Tests whether `nr_map_ids` & `map_ids` fields in `bpf_prog_info` is available. -pub(crate) fn is_info_map_ids_supported() -> bool { - with_trivial_prog(ProgramType::TracePoint, |attr| { - let prog_fd = match bpf_prog_load(attr) { - Ok(fd) => fd, - Err(_) => return false, - }; - bpf_obj_get_info_by_fd(prog_fd.as_fd(), |info: &mut bpf_prog_info| { - info.nr_map_ids = 1 - }) - .is_ok() - }) -} - -/// Tests whether `gpl_compatible` field in `bpf_prog_info` is available. -pub(crate) fn is_info_gpl_compatible_supported() -> bool { - with_trivial_prog(ProgramType::TracePoint, |attr| { - let prog_fd = match bpf_prog_load(attr) { - Ok(fd) => fd, - Err(_) => return false, - }; - if let Ok::(info) = bpf_obj_get_info_by_fd(prog_fd.as_fd(), |_| {}) { - return info.gpl_compatible() != 0; - } - false - }) -} - pub(crate) fn is_probe_read_kernel_supported() -> bool { let mut attr = unsafe { mem::zeroed::() }; let u = unsafe { &mut attr.__bindgen_anon_3 }; @@ -1114,7 +1086,7 @@ fn sys_bpf(cmd: bpf_cmd, attr: &mut bpf_attr) -> io::Result { }) } -fn unit_sys_bpf(cmd: bpf_cmd, attr: &mut bpf_attr) -> io::Result<()> { +pub(super) fn unit_sys_bpf(cmd: bpf_cmd, attr: &mut bpf_attr) -> io::Result<()> { sys_bpf(cmd, attr).map(|code| assert_eq!(code, 0)) } diff --git a/aya/src/sys/feature_probe.rs b/aya/src/sys/feature_probe.rs index c710a349..eaf18bf1 100644 --- a/aya/src/sys/feature_probe.rs +++ b/aya/src/sys/feature_probe.rs @@ -4,12 +4,15 @@ use std::{mem, os::fd::AsRawFd as _}; use aya_obj::{ btf::{Btf, BtfKind}, - generated::{BPF_F_MMAPABLE, BPF_F_NO_PREALLOC, bpf_attr, bpf_cmd, bpf_map_type}, + generated::{ + BPF_F_MMAPABLE, BPF_F_NO_PREALLOC, bpf_attr, bpf_cmd, bpf_map_type, bpf_prog_info, + }, }; use libc::{E2BIG, EBADF, EINVAL}; -use super::{SyscallError, bpf_prog_load, fd_sys_bpf, with_trivial_prog}; +use super::{SyscallError, bpf_prog_load, fd_sys_bpf, unit_sys_bpf, with_trivial_prog}; use crate::{ + MockableFd, maps::MapType, programs::{ProgramError, ProgramType}, util::page_size, @@ -28,7 +31,7 @@ use crate::{ /// match is_program_supported(ProgramType::Xdp) { /// Ok(true) => println!("XDP supported :)"), /// Ok(false) => println!("XDP not supported :("), -/// Err(err) => println!("Uh oh! Unexpected error: {:?}", err), +/// Err(err) => println!("Uh oh! Unexpected error while probing: {:?}", err), /// } /// ``` /// @@ -119,7 +122,7 @@ pub fn is_program_supported(program_type: ProgramType) -> Result println!("hash_of_maps supported :)"), /// Ok(false) => println!("hash_of_maps not supported :("), -/// Err(err) => println!("Uh oh! Unexpected error: {:?}", err), +/// Err(err) => println!("Uh oh! Unexpected error while probing: {:?}", err), /// } /// ``` /// @@ -247,3 +250,59 @@ pub fn is_map_supported(map_type: MapType) -> Result { }), } } + +/// Whether `nr_map_ids` & `map_ids` fields in `bpf_prog_info` are supported. +pub(crate) fn is_prog_info_map_ids_supported() -> Result { + let fd = with_trivial_prog(ProgramType::SocketFilter, |attr| { + bpf_prog_load(attr).map_err(|io_error| { + ProgramError::SyscallError(SyscallError { + call: "bpf_prog_load", + io_error, + }) + }) + })?; + // SAFETY: all-zero byte-pattern valid for `bpf_prog_info` + let mut info = unsafe { mem::zeroed::() }; + info.nr_map_ids = 1; + + probe_bpf_info(fd, info).map_err(ProgramError::from) +} + +/// Tests whether `bpf_prog_info.gpl_compatible` field is supported. +pub(crate) fn is_prog_info_license_supported() -> Result { + let fd = with_trivial_prog(ProgramType::SocketFilter, |attr| { + bpf_prog_load(attr).map_err(|io_error| { + ProgramError::SyscallError(SyscallError { + call: "bpf_prog_load", + io_error, + }) + }) + })?; + // SAFETY: all-zero byte-pattern valid for `bpf_prog_info` + let mut info = unsafe { mem::zeroed::() }; + info.set_gpl_compatible(1); + + probe_bpf_info(fd, info).map_err(ProgramError::from) +} + +/// Probes program and map info. +fn probe_bpf_info(fd: MockableFd, info: T) -> Result { + // SAFETY: all-zero byte-pattern valid for `bpf_attr` + let mut attr = unsafe { mem::zeroed::() }; + attr.info.bpf_fd = fd.as_raw_fd() as u32; + attr.info.info_len = mem::size_of_val(&info) as u32; + attr.info.info = &info as *const _ as u64; + + let io_error = match unit_sys_bpf(bpf_cmd::BPF_OBJ_GET_INFO_BY_FD, &mut attr) { + Ok(()) => return Ok(true), + Err(io_error) => io_error, + }; + match io_error.raw_os_error() { + // `E2BIG` from `bpf_check_uarg_tail_zero()` + Some(E2BIG) => Ok(false), + _ => Err(SyscallError { + call: "bpf_obj_get_info_by_fd", + io_error, + }), + } +} diff --git a/test/integration-test/src/tests/info.rs b/test/integration-test/src/tests/info.rs index 99c7af46..88c699f7 100644 --- a/test/integration-test/src/tests/info.rs +++ b/test/integration-test/src/tests/info.rs @@ -12,6 +12,7 @@ use aya::{ Ebpf, maps::{Array, HashMap, IterableMap as _, MapError, MapType, loaded_maps}, programs::{ProgramError, ProgramType, SocketFilter, TracePoint, UProbe, loaded_programs}, + sys::feature_probe::{is_map_supported, is_program_supported}, util::KernelVersion, }; use libc::EINVAL; @@ -20,7 +21,11 @@ use crate::utils::{kernel_assert, kernel_assert_eq}; #[test] fn test_loaded_programs() { - // Load a program. + if !is_program_supported(ProgramType::SocketFilter).unwrap() { + eprintln!("skipping test - socket_filter program not supported"); + return; + } + // Since we are only testing the programs for their metadata, there is no need to "attach" them. let mut bpf = Ebpf::load(crate::TEST).unwrap(); let prog: &mut UProbe = bpf.program_mut("test_uprobe").unwrap().try_into().unwrap(); @@ -33,9 +38,7 @@ fn test_loaded_programs() { if let ProgramError::SyscallError(err) = &err { // Skip entire test since feature not available if err.io_error.raw_os_error() == Some(EINVAL) { - eprintln!( - "ignoring test completely as `loaded_programs()` is not available on the host" - ); + eprintln!("skipping test - `loaded_programs()` not supported"); return; } } @@ -71,6 +74,11 @@ fn test_loaded_programs() { #[test] fn test_program_info() { + if !is_program_supported(ProgramType::SocketFilter).unwrap() { + eprintln!("skipping test - socket_filter program not supported"); + return; + } + // Kernels below v4.15 have been observed to have `bpf_jit_enable` disabled by default. let _guard = ensure_sysctl_enabled("/proc/sys/net/core/bpf_jit_enable"); @@ -129,6 +137,11 @@ fn test_program_info() { #[test] fn test_loaded_at() { + if !is_program_supported(ProgramType::SocketFilter).unwrap() { + eprintln!("skipping test - socket_filter program not supported"); + return; + } + let mut bpf: Ebpf = Ebpf::load(crate::SIMPLE_PROG).unwrap(); let prog: &mut SocketFilter = bpf.program_mut("simple_prog").unwrap().try_into().unwrap(); @@ -144,9 +157,7 @@ fn test_loaded_at() { let loaded_at = match prog.info().unwrap().loaded_at() { Some(time) => time, None => { - eprintln!( - "ignoring test completely as `load_time` field of `bpf_prog_info` is not available on the host" - ); + eprintln!("skipping test - `bpf_prog_info.load_time` field not supported"); return; } }; @@ -175,11 +186,12 @@ fn test_loaded_at() { #[test] fn test_prog_stats() { - // Test depends on whether trace point exists. + if !is_program_supported(ProgramType::TracePoint).unwrap() { + eprintln!("skipping test - tracepoint program not supported"); + return; + } if !Path::new("/sys/kernel/debug/tracing/events/syscalls/sys_enter_bpf").exists() { - eprintln!( - "ignoring test completely as `syscalls/sys_enter_bpf` is not available on the host" - ); + eprintln!("skipping test - `syscalls/sys_enter_bpf` not available"); return; } @@ -200,6 +212,17 @@ fn test_prog_stats() { #[test] fn list_loaded_maps() { + if !is_program_supported(ProgramType::SocketFilter).unwrap() { + eprintln!("skipping test - socket_filter program not supported"); + return; + } else if !is_map_supported(MapType::Hash).unwrap() { + eprintln!("skipping test - hash map not supported"); + return; + } else if !is_map_supported(MapType::Array).unwrap() { + eprintln!("skipping test - array map not supported"); + return; + } + // Load a program with maps. let mut bpf: Ebpf = Ebpf::load(crate::MAP_TEST).unwrap(); let prog: &mut SocketFilter = bpf.program_mut("simple_prog").unwrap().try_into().unwrap(); @@ -210,9 +233,7 @@ fn list_loaded_maps() { if let Err(err) = maps.peek().unwrap() { if let MapError::SyscallError(err) = &err { if err.io_error.raw_os_error() == Some(EINVAL) { - eprintln!( - "ignoring test completely as `loaded_maps()` is not available on the host" - ); + eprintln!("skipping test - `loaded_maps()` not supported"); return; } } @@ -250,6 +271,17 @@ fn list_loaded_maps() { #[test] fn test_map_info() { + if !is_program_supported(ProgramType::SocketFilter).unwrap() { + eprintln!("skipping test - socket_filter program not supported"); + return; + } else if !is_map_supported(MapType::Hash).unwrap() { + eprintln!("skipping test - hash map not supported"); + return; + } else if !is_map_supported(MapType::Array).unwrap() { + eprintln!("skipping test - array map not supported"); + return; + } + let mut bpf: Ebpf = Ebpf::load(crate::MAP_TEST).unwrap(); let prog: &mut SocketFilter = bpf.program_mut("simple_prog").unwrap().try_into().unwrap(); prog.load().unwrap(); diff --git a/xtask/public-api/aya-obj.txt b/xtask/public-api/aya-obj.txt index 7f00a679..5659ef0e 100644 --- a/xtask/public-api/aya-obj.txt +++ b/xtask/public-api/aya-obj.txt @@ -7725,8 +7725,6 @@ pub fn aya_obj::Features::bpf_probe_read_kernel(&self) -> bool pub fn aya_obj::Features::btf(&self) -> core::option::Option<&aya_obj::btf::BtfFeatures> pub fn aya_obj::Features::cpumap_prog_id(&self) -> bool pub fn aya_obj::Features::devmap_prog_id(&self) -> bool -pub fn aya_obj::Features::prog_info_gpl_compatible(&self) -> bool -pub fn aya_obj::Features::prog_info_map_ids(&self) -> bool impl core::default::Default for aya_obj::Features pub fn aya_obj::Features::default() -> aya_obj::Features impl core::fmt::Debug for aya_obj::Features @@ -8588,8 +8586,6 @@ pub fn aya_obj::Features::bpf_probe_read_kernel(&self) -> bool pub fn aya_obj::Features::btf(&self) -> core::option::Option<&aya_obj::btf::BtfFeatures> pub fn aya_obj::Features::cpumap_prog_id(&self) -> bool pub fn aya_obj::Features::devmap_prog_id(&self) -> bool -pub fn aya_obj::Features::prog_info_gpl_compatible(&self) -> bool -pub fn aya_obj::Features::prog_info_map_ids(&self) -> bool impl core::default::Default for aya_obj::Features pub fn aya_obj::Features::default() -> aya_obj::Features impl core::fmt::Debug for aya_obj::Features From 0bf64aa0d1f94cccbe6fc0f60a096696480c9e81 Mon Sep 17 00:00:00 2001 From: Tyrone Wu Date: Fri, 28 Mar 2025 22:03:48 +0000 Subject: [PATCH 4/4] aya: short-circuit info field if non-zero Short-circuits `CACHE` to true if the field is non-zero. This saves from executing the probing logic since the logic essentially checks if the field can process (or doesn't error) non-zero value. --- aya/src/programs/info.rs | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/aya/src/programs/info.rs b/aya/src/programs/info.rs index 753d6054..ef6b5378 100644 --- a/aya/src/programs/info.rs +++ b/aya/src/programs/info.rs @@ -113,7 +113,9 @@ impl ProgramInfo { pub fn map_ids(&self) -> Result>, ProgramError> { static CACHE: OnceLock = OnceLock::new(); CACHE - .get_or_init(|| matches!(is_prog_info_map_ids_supported(), Ok(true))) + .get_or_init(|| { + self.0.nr_map_ids > 0 || matches!(is_prog_info_map_ids_supported(), Ok(true)) + }) .then(|| { let mut map_ids = vec![0u32; self.0.nr_map_ids as usize]; bpf_prog_get_info_by_fd(self.fd()?.as_fd(), &mut map_ids)?; @@ -147,7 +149,9 @@ impl ProgramInfo { pub fn gpl_compatible(&self) -> Option { static CACHE: OnceLock = OnceLock::new(); CACHE - .get_or_init(|| matches!(is_prog_info_license_supported(), Ok(true))) + .get_or_init(|| { + self.0.gpl_compatible() != 0 || matches!(is_prog_info_license_supported(), Ok(true)) + }) .then_some(self.0.gpl_compatible() != 0) }