test: Add smoke test for BPF_PROG_TYPE_EXT

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

test/cases/000_smoke/010_ext/ext.bpf.c

@@ -0,0 +1,11 @@
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+SEC("xdp/drop")
+int xdp_drop(struct xdp_md *ctx)
+{
+    return XDP_DROP;
+}
+
+char _license[] SEC("license") = "GPL";

test/cases/000_smoke/010_ext/ext.rs

@@ -0,0 +1,24 @@
+//! ```cargo
+//! [dependencies]
+//! aya = { path = "../../../../aya" }
+//! ```
+
+use aya::{
+    Bpf, BpfLoader,
+    programs::{Extension, ProgramFd, Xdp, XdpFlags},
+};
+use std::convert::TryInto;
+
+fn main() {
+    println!("Loading Root XDP program");
+    let mut bpf = Bpf::load_file("main.o").unwrap();
+    let pass: &mut Xdp = bpf.program_mut("pass").unwrap().try_into().unwrap();
+    pass.load().unwrap();
+    pass.attach("lo", XdpFlags::default()).unwrap();
+
+    println!("Loading Extension Program");
+    let mut bpf = BpfLoader::new().extension("drop").load_file("ext.o").unwrap();
+    let drop_: &mut Extension = bpf.program_mut("drop").unwrap().try_into().unwrap();
+    drop_.load(pass.fd().unwrap(), "xdp_pass").unwrap();
+    println!("Success...");
+}

test/cases/000_smoke/010_ext/main.bpf.c

@@ -0,0 +1,11 @@
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+SEC("xdp/pass")
+int xdp_pass(struct xdp_md *ctx)
+{
+    return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";

test/cases/000_smoke/010_ext/test.sh

@@ -0,0 +1,31 @@
+#!/bin/sh
+# SUMMARY: Check that a simple XDP program an be loaded
+# LABELS:
+
+set -e
+
+# Source libraries. Uncomment if needed/defined
+#. "${RT_LIB}"
+. "${RT_PROJECT_ROOT}/_lib/lib.sh"
+
+NAME=ext
+
+clean_up() {
+    rm -rf main.o ${NAME}.o ${NAME}
+    exec_vm rm -f main.o ${NAME}.o ${NAME}
+}
+
+trap clean_up EXIT
+
+# Test code goes here
+compile_c_ebpf "$(pwd)/main.bpf.c"
+compile_c_ebpf "$(pwd)/${NAME}.bpf.c"
+compile_user "$(pwd)/${NAME}.rs"
+
+scp_vm main.o
+scp_vm ${NAME}.o
+scp_vm ${NAME}
+
+exec_vm sudo ./${NAME}
+
+exit 0