test: replace lo interface with dummy interface

Fixes: aya-rs#422

Signed-off-by: murex971 <nupur202000@gmail.com>

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

@@ -11,7 +11,7 @@ use aya::{
 };
 use log::warn;
 
-use crate::tests::kernel_version;
+use crate::tests::{kernel_version, util::DummyInterface};
 
 use super::{integration_test, IntegrationTest};
 
@@ -28,7 +28,10 @@ fn long_name() {
         .try_into()
         .unwrap();
     name_prog.load().unwrap();
-    name_prog.attach("lo", XdpFlags::default()).unwrap();
+    let _iface = DummyInterface::new();
+    name_prog
+        .attach(DummyInterface::TEST_DUMMY, XdpFlags::default())
+        .unwrap();
 
     // We used to be able to assert with bpftool that the program name was short.
     // It seem though that it now uses the name from the ELF symbol table instead.
@@ -94,7 +97,10 @@ fn unload_xdp() {
         .unwrap();
     prog.load().unwrap();
     assert_loaded!("test_unload_xdp", true);
-    let link = prog.attach("lo", XdpFlags::default()).unwrap();
+    let _iface = DummyInterface::new();
+    let link = prog
+        .attach(DummyInterface::TEST_DUMMY, XdpFlags::default())
+        .unwrap();
     {
         let _link_owned = prog.take_link(link).unwrap();
         prog.unload().unwrap();
@@ -105,7 +111,8 @@ fn unload_xdp() {
     prog.load().unwrap();
 
     assert_loaded!("test_unload_xdp", true);
-    prog.attach("lo", XdpFlags::default()).unwrap();
+    prog.attach(DummyInterface::TEST_DUMMY, XdpFlags::default())
+        .unwrap();
 
     assert_loaded!("test_unload_xdp", true);
     prog.unload().unwrap();
@@ -158,7 +165,10 @@ fn pin_link() {
         .try_into()
         .unwrap();
     prog.load().unwrap();
-    let link_id = prog.attach("lo", XdpFlags::default()).unwrap();
+    let _iface = DummyInterface::new();
+    let link_id = prog
+        .attach(DummyInterface::TEST_DUMMY, XdpFlags::default())
+        .unwrap();
     let link = prog.take_link(link_id).unwrap();
     assert_loaded!("test_unload_xdp", true);
 
@@ -207,9 +217,12 @@ fn pin_lifecycle() {
     assert_loaded!("pass", true);
 
     // 3. Load program from bpffs and attach
+    let _iface = DummyInterface::new();
     {
         let mut prog = Xdp::from_pin("/sys/fs/bpf/aya-xdp-test-prog").unwrap();
-        let link_id = prog.attach("lo", XdpFlags::default()).unwrap();
+        let link_id = prog
+            .attach(DummyInterface::TEST_DUMMY, XdpFlags::default())
+            .unwrap();
         let link = prog.take_link(link_id).unwrap();
         let fd_link: FdLink = link.try_into().unwrap();
         fd_link.pin("/sys/fs/bpf/aya-xdp-test-lo").unwrap();

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

@@ -9,6 +9,7 @@ pub mod load;
 pub mod rbpf;
 pub mod relocations;
 pub mod smoke;
+mod util;
 
 pub use integration_test_macros::integration_test;
 #[derive(Debug)]

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

@@ -5,15 +5,18 @@ use aya::{
 };
 use log::info;
 
-use super::{integration_test, kernel_version, IntegrationTest};
+use super::{integration_test, kernel_version, util::DummyInterface, IntegrationTest};
 
 #[integration_test]
 fn xdp() {
     let bytes = include_bytes_aligned!("../../../../target/bpfel-unknown-none/debug/pass");
     let mut bpf = Bpf::load(bytes).unwrap();
     let dispatcher: &mut Xdp = bpf.program_mut("pass").unwrap().try_into().unwrap();
     dispatcher.load().unwrap();
-    dispatcher.attach("lo", XdpFlags::default()).unwrap();
+    let _iface = DummyInterface::new();
+    dispatcher
+        .attach(DummyInterface::TEST_DUMMY, XdpFlags::default())
+        .unwrap();
 }
 
 #[integration_test]
@@ -32,7 +35,9 @@ fn extension() {
     let mut bpf = Bpf::load(main_bytes).unwrap();
     let pass: &mut Xdp = bpf.program_mut("pass").unwrap().try_into().unwrap();
     pass.load().unwrap();
-    pass.attach("lo", XdpFlags::default()).unwrap();
+    let _iface = DummyInterface::new();
+    pass.attach(DummyInterface::TEST_DUMMY, XdpFlags::default())
+        .unwrap();
 
     let ext_bytes = include_bytes_aligned!("../../../../target/bpfel-unknown-none/debug/ext.bpf.o");
     let mut bpf = BpfLoader::new().extension("drop").load(ext_bytes).unwrap();

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

@@ -0,0 +1,27 @@
+use std::process::Command;
+
+pub(crate) struct DummyInterface;
+
+impl DummyInterface {
+    pub const TEST_DUMMY: &str = "aya-dummy";
+
+    pub fn new() -> Self {
+        let output = Command::new("ip")
+            .args(["link", "add", Self::TEST_DUMMY, "type", "dummy"])
+            .output()
+            .expect("failed to run ip command");
+
+        assert!(output.status.success());
+        Self
+    }
+}
+
+impl Drop for DummyInterface {
+    fn drop(&mut self) {
+        let output = Command::new("ip")
+            .args(["link", "del", Self::TEST_DUMMY])
+            .output()
+            .expect("failed to run ip command");
+        assert!(output.status.success())
+    }
+}