[PATCH v1 bpf-next 3/9] bpftool: open and load bpf object

[Manu Bretelle <chantr4@gmail.com>]

Add an initial test that excercises opening and loading a bpf object.

    BPFTOOL_PATH=../bpftool
    CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_RUNNER="sudo -E" cargo test --
    --nocapture
        Finished test [unoptimized + debuginfo] target(s) in 0.04s
         Running unittests src/main.rs
    (target/debug/deps/bpftool_tests-afa5a7eef3cdeafb)

    running 2 tests
    Running command "../bpftool" "version"
    Running command "../bpftool" "map" "list" "--json"
    test bpftool_tests::run_bpftool ... ok
    test bpftool_tests::run_bpftool_map_list ... ok

    test result: ok. 2 passed; 0 failed; 0 ignored; 0 measured; 0 filtered
    out; finished in 0.19s

Signed-off-by: Manu Bretelle <chantr4@gmail.com>
---
 .../selftests/bpf/bpftool_tests/Cargo.toml    |  3 ++
 .../bpf/bpftool_tests/src/bpftool_tests.rs    | 50 +++++++++++++++++++
 2 files changed, 53 insertions(+)

diff --git a/tools/testing/selftests/bpf/bpftool_tests/Cargo.toml b/tools/testing/selftests/bpf/bpftool_tests/Cargo.toml
index 35c834082351..cc1fa65189f2 100644
--- a/tools/testing/selftests/bpf/bpftool_tests/Cargo.toml
+++ b/tools/testing/selftests/bpf/bpftool_tests/Cargo.toml
@@ -5,7 +5,10 @@ edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 [dependencies]
+anyhow = "1"
 libbpf-rs = "0.21"
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
 
 [build-dependencies]
 libbpf-cargo = "0.21"
diff --git a/tools/testing/selftests/bpf/bpftool_tests/src/bpftool_tests.rs b/tools/testing/selftests/bpf/bpftool_tests/src/bpftool_tests.rs
index 35eb35831dce..fb58898a4a1a 100644
--- a/tools/testing/selftests/bpf/bpftool_tests/src/bpftool_tests.rs
+++ b/tools/testing/selftests/bpf/bpftool_tests/src/bpftool_tests.rs
@@ -3,11 +3,49 @@ mod bpftool_tests_skel {
     include!(concat!(env!("OUT_DIR"), "/bpftool_tests.skel.rs"));
 }
 
+use anyhow::Result;
+use bpftool_tests_skel::BpftoolTestsSkel;
+use bpftool_tests_skel::BpftoolTestsSkelBuilder;
+use libbpf_rs::skel::OpenSkel;
+use libbpf_rs::skel::SkelBuilder;
+use serde::Deserialize;
+use serde::Serialize;
+
 use std::process::Command;
 
 const BPFTOOL_PATH_ENV: &str = "BPFTOOL_PATH";
 const BPFTOOL_PATH: &str = "/usr/sbin/bpftool";
 
+/// A struct representing a pid entry from map/prog dump
+#[derive(Serialize, Deserialize, Debug)]
+struct Pid {
+    comm: String,
+    pid: u64,
+}
+
+/// A struct representing a map entry from `bpftool map list -j`
+#[derive(Serialize, Deserialize, Debug)]
+struct Map {
+    name: Option<String>,
+    id: u64,
+    r#type: String,
+    #[serde(default)]
+    pids: Vec<Pid>,
+}
+
+/// Setup our bpftool_tests.bpf.c program.
+/// Open and load and return an opened object.
+fn setup() -> Result<BpftoolTestsSkel<'static>> {
+    let mut skel_builder = BpftoolTestsSkelBuilder::default();
+    skel_builder.obj_builder.debug(false);
+
+    let open_skel = skel_builder.open()?;
+
+    let skel = open_skel.load()?;
+
+    Ok(skel)
+}
+
 /// Run a bpftool command and returns the output
 fn run_bpftool_command(args: &[&str]) -> std::process::Output {
     let mut cmd = Command::new(std::env::var(BPFTOOL_PATH_ENV).unwrap_or(BPFTOOL_PATH.to_string()));
@@ -22,3 +60,15 @@ fn run_bpftool() {
     let output = run_bpftool_command(&["version"]);
     assert!(output.status.success());
 }
+
+/// A test to validate that we can list maps using bpftool
+#[test]
+fn run_bpftool_map_list() {
+    let _skel = setup().expect("Failed to set up BPF program");
+    let output = run_bpftool_command(&["map", "list", "--json"]);
+
+    let maps = serde_json::from_slice::<Vec<Map>>(&output.stdout).expect("Failed to parse JSON");
+
+    assert!(output.status.success(), "bpftool returned an error.");
+    assert!(!maps.is_empty(), "No maps were listed");
+}
-- 
2.39.3