kernel

linux-6.8.1/tools/testing/selftests/bpf/test_cpp.cpp

@@ -0,0 +1,130 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+#include <iostream>
+#include <unistd.h>
+#include <linux/bpf.h>
+#include <linux/btf.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+#include <bpf/btf.h>
+#include "test_core_extern.skel.h"
+
+template <typename T>
+class Skeleton {
+private:
+	T *skel;
+public:
+	Skeleton(): skel(nullptr) { }
+
+	~Skeleton() { if (skel) T::destroy(skel); }
+
+	int open(const struct bpf_object_open_opts *opts = nullptr)
+	{
+		int err;
+
+		if (skel)
+			return -EBUSY;
+
+		skel = T::open(opts);
+		err = libbpf_get_error(skel);
+		if (err) {
+			skel = nullptr;
+			return err;
+		}
+
+		return 0;
+	}
+
+	int load() { return T::load(skel); }
+
+	int attach() { return T::attach(skel); }
+
+	void detach() { return T::detach(skel); }
+
+	const T* operator->() const { return skel; }
+
+	T* operator->() { return skel; }
+
+	const T *get() const { return skel; }
+};
+
+static void dump_printf(void *ctx, const char *fmt, va_list args)
+{
+}
+
+static void try_skeleton_template()
+{
+	Skeleton<test_core_extern> skel;
+	std::string prog_name;
+	int err;
+	LIBBPF_OPTS(bpf_object_open_opts, opts);
+
+	err = skel.open(&opts);
+	if (err) {
+		fprintf(stderr, "Skeleton open failed: %d\n", err);
+		return;
+	}
+
+	skel->data->kern_ver = 123;
+	skel->data->int_val = skel->data->ushort_val;
+
+	err = skel.load();
+	if (err) {
+		fprintf(stderr, "Skeleton load failed: %d\n", err);
+		return;
+	}
+
+	if (!skel->kconfig->CONFIG_BPF_SYSCALL)
+		fprintf(stderr, "Seems like CONFIG_BPF_SYSCALL isn't set?!\n");
+
+	err = skel.attach();
+	if (err) {
+		fprintf(stderr, "Skeleton attach failed: %d\n", err);
+		return;
+	}
+
+	prog_name = bpf_program__name(skel->progs.handle_sys_enter);
+	if (prog_name != "handle_sys_enter")
+		fprintf(stderr, "Unexpected program name: %s\n", prog_name.c_str());
+
+	bpf_link__destroy(skel->links.handle_sys_enter);
+	skel->links.handle_sys_enter = bpf_program__attach(skel->progs.handle_sys_enter);
+
+	skel.detach();
+
+	/* destructor will destroy underlying skeleton */
+}
+
+int main(int argc, char *argv[])
+{
+	struct btf_dump_opts opts = { };
+	struct test_core_extern *skel;
+	struct btf *btf;
+	int fd;
+
+	try_skeleton_template();
+
+	/* libbpf.h */
+	libbpf_set_print(NULL);
+
+	/* bpf.h */
+	bpf_prog_get_fd_by_id(0);
+
+	/* btf.h */
+	btf = btf__new(NULL, 0);
+	if (!libbpf_get_error(btf))
+		btf_dump__new(btf, dump_printf, nullptr, &opts);
+
+	/* BPF skeleton */
+	skel = test_core_extern__open_and_load();
+	test_core_extern__destroy(skel);
+
+	fd = bpf_enable_stats(BPF_STATS_RUN_TIME);
+	if (fd < 0)
+		std::cout << "FAILED to enable stats: " << fd << std::endl;
+	else
+		::close(fd);
+
+	std::cout << "DONE!" << std::endl;
+
+	return 0;
+}