// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2021 Facebook */
#include <test_progs.h>
#include "test_legacy_printk.skel.h"

static int execute_one_variant(bool legacy)
{
        struct test_legacy_printk *skel;
        int err, zero = 0, my_pid = getpid(), res, map_fd;

        skel = test_legacy_printk__open();
        if (!ASSERT_OK_PTR(skel, "skel_open"))
                return -errno;

        bpf_program__set_autoload(skel->progs.handle_legacy, legacy);
        bpf_program__set_autoload(skel->progs.handle_modern, !legacy);

        err = test_legacy_printk__load(skel);
        /* no ASSERT_OK, we expect one of two variants can fail here */
        if (err)
                goto err_out;

        if (legacy) {
                map_fd = bpf_map__fd(skel->maps.my_pid_map);
                err = bpf_map_update_elem(map_fd, &zero, &my_pid, BPF_ANY);
                if (!ASSERT_OK(err, "my_pid_map_update"))
                        goto err_out;
                err = bpf_map_lookup_elem(map_fd, &zero, &res);
        } else {
                skel->bss->my_pid_var = my_pid;
        }

        err = test_legacy_printk__attach(skel);
        if (!ASSERT_OK(err, "skel_attach"))
                goto err_out;

        usleep(1); /* trigger */

        if (legacy) {
                map_fd = bpf_map__fd(skel->maps.res_map);
                err = bpf_map_lookup_elem(map_fd, &zero, &res);
                if (!ASSERT_OK(err, "res_map_lookup"))
                        goto err_out;
        } else {
                res = skel->bss->res_var;
        }

        if (!ASSERT_GT(res, 0, "res")) {
                err = -EINVAL;
                goto err_out;
        }

err_out:
        test_legacy_printk__destroy(skel);
        return err;
}

void test_legacy_printk(void)
{
        /* legacy variant should work everywhere */
        ASSERT_OK(execute_one_variant(true /* legacy */), "legacy_case");

        /* execute modern variant, can fail the load on old kernels */
        execute_one_variant(false);
}