tests: Add integration test for pinning lifecycle

Signed-off-by: Dave Tucker <dave@dtucker.co.uk>

aya/src/programs/links.rs

@@ -187,7 +187,7 @@ impl PinnedLink {
         }
     }
 
-    /// Creates a [`PinnedLink`] from a valid path on bpffs
+    /// Creates a [`PinnedLink`] from a valid path on bpffs.
     pub fn from_path<P: AsRef<Path>>(path: P) -> Result<Self, LinkError> {
         let path_string = CString::new(path.as_ref().to_string_lossy().to_string()).unwrap();
         let fd =

test/integration-test/src/tests/load.rs

@@ -3,7 +3,10 @@ use std::{process::Command, thread, time};
 use aya::{
     include_bytes_aligned,
     maps::{Array, MapRefMut},
-    programs::{links::FdLink, TracePoint, Xdp, XdpFlags},
+    programs::{
+        links::{FdLink, PinnedLink},
+        TracePoint, Xdp, XdpFlags,
+    },
     Bpf,
 };
 
@@ -60,14 +63,14 @@ fn multiple_btf_maps() -> anyhow::Result<()> {
     Ok(())
 }
 
-fn is_loaded() -> bool {
+fn is_loaded(name: &str) -> bool {
     let output = Command::new("bpftool").args(["prog"]).output().unwrap();
     let stdout = String::from_utf8(output.stdout).unwrap();
-    stdout.contains("test_unload")
+    stdout.contains(name)
 }
 
-fn assert_loaded(loaded: bool) {
-    let state = is_loaded();
+fn assert_loaded(name: &str, loaded: bool) {
+    let state = is_loaded(name);
     if state == loaded {
         return;
     }
@@ -84,19 +87,19 @@ fn unload() -> anyhow::Result<()> {
     {
         let _link_owned = prog.take_link(link);
         prog.unload().unwrap();
-        assert_loaded(true);
+        assert_loaded("test_unload", true);
     };
 
-    assert_loaded(false);
+    assert_loaded("test_unload", false);
     prog.load().unwrap();
 
-    assert_loaded(true);
+    assert_loaded("test_unload", true);
     prog.attach("lo", XdpFlags::default()).unwrap();
 
-    assert_loaded(true);
+    assert_loaded("test_unload", true);
     prog.unload().unwrap();
 
-    assert_loaded(false);
+    assert_loaded("test_unload", false);
     Ok(())
 }
 
@@ -108,24 +111,57 @@ fn pin_link() -> anyhow::Result<()> {
     prog.load().unwrap();
     let link_id = prog.attach("lo", XdpFlags::default()).unwrap();
     let link = prog.take_link(link_id)?;
-    assert_loaded(true);
+    assert_loaded("test_unload", true);
 
     let fd_link: FdLink = link.try_into()?;
     let pinned = fd_link.pin("/sys/fs/bpf/aya-xdp-test-lo")?;
 
     // because of the pin, the program is still attached
     prog.unload()?;
-    assert_loaded(true);
+    assert_loaded("test_unload", true);
 
     // delete the pin, but the program is still attached
     let new_link = pinned.unpin()?;
-    println!("third assert");
-    assert_loaded(true);
+    assert_loaded("test_unload", true);
 
     // finally when new_link is dropped we're detached
     drop(new_link);
-    println!("final assert");
-    assert_loaded(false);
+    assert_loaded("test_unload", false);
+
+    Ok(())
+}
+
+#[integration_test]
+fn pin_lifecycle() -> anyhow::Result<()> {
+    let bytes = include_bytes_aligned!("../../../../target/bpfel-unknown-none/debug/pass");
+
+    // 1. Load Program and Pin
+    {
+        let mut bpf = Bpf::load(bytes)?;
+        let prog: &mut Xdp = bpf.program_mut("pass").unwrap().try_into().unwrap();
+        prog.load().unwrap();
+        let link_id = prog.attach("lo", XdpFlags::default()).unwrap();
+        let link = prog.take_link(link_id)?;
+        let fd_link: FdLink = link.try_into()?;
+        fd_link.pin("/sys/fs/bpf/aya-xdp-test-lo")?;
+    }
+
+    // should still be loaded since link was pinned
+    assert_loaded("pass", true);
+
+    // 2. Load a new version of the program, unpin link, and atomically replace old program
+    {
+        let mut bpf = Bpf::load(bytes)?;
+        let prog: &mut Xdp = bpf.program_mut("pass").unwrap().try_into().unwrap();
+        prog.load().unwrap();
+
+        let link = PinnedLink::from_path("/sys/fs/bpf/aya-xdp-test-lo")?.unpin()?;
+        prog.attach_to_link(link.try_into()?)?;
+        assert_loaded("pass", true);
+    }
+
+    // program should be unloaded
+    assert_loaded("pass", false);
 
     Ok(())
 }