// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2021 Facebook */

#include <test_progs.h>
#include <network_helpers.h>
#include "bpf_loop.skel.h"

static void check_nr_loops(struct bpf_loop *skel)
{
        struct bpf_link *link;

        link = bpf_program__attach(skel->progs.test_prog);
        if (!ASSERT_OK_PTR(link, "link"))
                return;

        /* test 0 loops */
        skel->bss->nr_loops = 0;

        usleep(1);

        ASSERT_EQ(skel->bss->nr_loops_returned, skel->bss->nr_loops,
                  "0 loops");

        /* test 500 loops */
        skel->bss->nr_loops = 500;

        usleep(1);

        ASSERT_EQ(skel->bss->nr_loops_returned, skel->bss->nr_loops,
                  "500 loops");
        ASSERT_EQ(skel->bss->g_output, (500 * 499) / 2, "g_output");

        /* test exceeding the max limit */
        skel->bss->nr_loops = -1;

        usleep(1);

        ASSERT_EQ(skel->bss->err, -E2BIG, "over max limit");

        bpf_link__destroy(link);
}

static void check_callback_fn_stop(struct bpf_loop *skel)
{
        struct bpf_link *link;

        link = bpf_program__attach(skel->progs.test_prog);
        if (!ASSERT_OK_PTR(link, "link"))
                return;

        /* testing that loop is stopped when callback_fn returns 1 */
        skel->bss->nr_loops = 400;
        skel->data->stop_index = 50;

        usleep(1);

        ASSERT_EQ(skel->bss->nr_loops_returned, skel->data->stop_index + 1,
                  "nr_loops_returned");
        ASSERT_EQ(skel->bss->g_output, (50 * 49) / 2,
                  "g_output");

        bpf_link__destroy(link);
}

static void check_null_callback_ctx(struct bpf_loop *skel)
{
        struct bpf_link *link;

        /* check that user is able to pass in a null callback_ctx */
        link = bpf_program__attach(skel->progs.prog_null_ctx);
        if (!ASSERT_OK_PTR(link, "link"))
                return;

        skel->bss->nr_loops = 10;

        usleep(1);

        ASSERT_EQ(skel->bss->nr_loops_returned, skel->bss->nr_loops,
                  "nr_loops_returned");

        bpf_link__destroy(link);
}

static void check_invalid_flags(struct bpf_loop *skel)
{
        struct bpf_link *link;

        /* check that passing in non-zero flags returns -EINVAL */
        link = bpf_program__attach(skel->progs.prog_invalid_flags);
        if (!ASSERT_OK_PTR(link, "link"))
                return;

        usleep(1);

        ASSERT_EQ(skel->bss->err, -EINVAL, "err");

        bpf_link__destroy(link);
}

static void check_nested_calls(struct bpf_loop *skel)
{
        __u32 nr_loops = 100, nested_callback_nr_loops = 4;
        struct bpf_link *link;

        /* check that nested calls are supported */
        link = bpf_program__attach(skel->progs.prog_nested_calls);
        if (!ASSERT_OK_PTR(link, "link"))
                return;

        skel->bss->nr_loops = nr_loops;
        skel->bss->nested_callback_nr_loops = nested_callback_nr_loops;

        usleep(1);

        ASSERT_EQ(skel->bss->nr_loops_returned, nr_loops * nested_callback_nr_loops
                  * nested_callback_nr_loops, "nr_loops_returned");
        ASSERT_EQ(skel->bss->g_output, (4 * 3) / 2 * nested_callback_nr_loops
                * nr_loops, "g_output");

        bpf_link__destroy(link);
}

static void check_non_constant_callback(struct bpf_loop *skel)
{
        struct bpf_link *link =
                bpf_program__attach(skel->progs.prog_non_constant_callback);

        if (!ASSERT_OK_PTR(link, "link"))
                return;

        skel->bss->callback_selector = 0x0F;
        usleep(1);
        ASSERT_EQ(skel->bss->g_output, 0x0F, "g_output #1");

        skel->bss->callback_selector = 0xF0;
        usleep(1);
        ASSERT_EQ(skel->bss->g_output, 0xF0, "g_output #2");

        bpf_link__destroy(link);
}

static void check_stack(struct bpf_loop *skel)
{
        struct bpf_link *link = bpf_program__attach(skel->progs.stack_check);
        const int max_key = 12;
        int key;
        int map_fd;

        if (!ASSERT_OK_PTR(link, "link"))
                return;

        map_fd = bpf_map__fd(skel->maps.map1);

        if (!ASSERT_GE(map_fd, 0, "bpf_map__fd"))
                goto out;

        for (key = 1; key <= max_key; ++key) {
                int val = key;
                int err = bpf_map_update_elem(map_fd, &key, &val, BPF_NOEXIST);

                if (!ASSERT_OK(err, "bpf_map_update_elem"))
                        goto out;
        }

        usleep(1);

        for (key = 1; key <= max_key; ++key) {
                int val;
                int err = bpf_map_lookup_elem(map_fd, &key, &val);

                if (!ASSERT_OK(err, "bpf_map_lookup_elem"))
                        goto out;
                if (!ASSERT_EQ(val, key + 1, "bad value in the map"))
                        goto out;
        }

out:
        bpf_link__destroy(link);
}

void test_bpf_loop(void)
{
        struct bpf_loop *skel;

        skel = bpf_loop__open_and_load();
        if (!ASSERT_OK_PTR(skel, "bpf_loop__open_and_load"))
                return;

        skel->bss->pid = getpid();

        if (test__start_subtest("check_nr_loops"))
                check_nr_loops(skel);
        if (test__start_subtest("check_callback_fn_stop"))
                check_callback_fn_stop(skel);
        if (test__start_subtest("check_null_callback_ctx"))
                check_null_callback_ctx(skel);
        if (test__start_subtest("check_invalid_flags"))
                check_invalid_flags(skel);
        if (test__start_subtest("check_nested_calls"))
                check_nested_calls(skel);
        if (test__start_subtest("check_non_constant_callback"))
                check_non_constant_callback(skel);
        if (test__start_subtest("check_stack"))
                check_stack(skel);

        bpf_loop__destroy(skel);
}