// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2021. Huawei Technologies Co., Ltd */
#include <test_progs.h>
#include "strncmp_test.skel.h"

static int trigger_strncmp(const struct strncmp_test *skel)
{
        int cmp;

        usleep(1);

        cmp = skel->bss->cmp_ret;
        if (cmp > 0)
                return 1;
        if (cmp < 0)
                return -1;
        return 0;
}

/*
 * Compare str and target after making str[i] != target[i].
 * When exp is -1, make str[i] < target[i] and delta = -1.
 */
static void strncmp_full_str_cmp(struct strncmp_test *skel, const char *name,
                                 int exp)
{
        size_t nr = sizeof(skel->bss->str);
        char *str = skel->bss->str;
        int delta = exp;
        int got;
        size_t i;

        memcpy(str, skel->rodata->target, nr);
        for (i = 0; i < nr - 1; i++) {
                str[i] += delta;

                got = trigger_strncmp(skel);
                ASSERT_EQ(got, exp, name);

                str[i] -= delta;
        }
}

static void test_strncmp_ret(void)
{
        struct strncmp_test *skel;
        int err, got;

        skel = strncmp_test__open();
        if (!ASSERT_OK_PTR(skel, "strncmp_test open"))
                return;

        bpf_program__set_autoload(skel->progs.do_strncmp, true);

        err = strncmp_test__load(skel);
        if (!ASSERT_EQ(err, 0, "strncmp_test load"))
                goto out;

        err = strncmp_test__attach(skel);
        if (!ASSERT_EQ(err, 0, "strncmp_test attach"))
                goto out;

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

        /* Empty str */
        skel->bss->str[0] = '\0';
        got = trigger_strncmp(skel);
        ASSERT_EQ(got, -1, "strncmp: empty str");

        /* Same string */
        memcpy(skel->bss->str, skel->rodata->target, sizeof(skel->bss->str));
        got = trigger_strncmp(skel);
        ASSERT_EQ(got, 0, "strncmp: same str");

        /* Not-null-terminated string  */
        memcpy(skel->bss->str, skel->rodata->target, sizeof(skel->bss->str));
        skel->bss->str[sizeof(skel->bss->str) - 1] = 'A';
        got = trigger_strncmp(skel);
        ASSERT_EQ(got, 1, "strncmp: not-null-term str");

        strncmp_full_str_cmp(skel, "strncmp: less than", -1);
        strncmp_full_str_cmp(skel, "strncmp: greater than", 1);
out:
        strncmp_test__destroy(skel);
}

static void test_strncmp_bad_not_const_str_size(void)
{
        struct strncmp_test *skel;
        int err;

        skel = strncmp_test__open();
        if (!ASSERT_OK_PTR(skel, "strncmp_test open"))
                return;

        bpf_program__set_autoload(skel->progs.strncmp_bad_not_const_str_size, true);

        err = strncmp_test__load(skel);
        ASSERT_ERR(err, "strncmp_test load bad_not_const_str_size");

        strncmp_test__destroy(skel);
}

static void test_strncmp_bad_writable_target(void)
{
        struct strncmp_test *skel;
        int err;

        skel = strncmp_test__open();
        if (!ASSERT_OK_PTR(skel, "strncmp_test open"))
                return;

        bpf_program__set_autoload(skel->progs.strncmp_bad_writable_target, true);

        err = strncmp_test__load(skel);
        ASSERT_ERR(err, "strncmp_test load bad_writable_target");

        strncmp_test__destroy(skel);
}

static void test_strncmp_bad_not_null_term_target(void)
{
        struct strncmp_test *skel;
        int err;

        skel = strncmp_test__open();
        if (!ASSERT_OK_PTR(skel, "strncmp_test open"))
                return;

        bpf_program__set_autoload(skel->progs.strncmp_bad_not_null_term_target, true);

        err = strncmp_test__load(skel);
        ASSERT_ERR(err, "strncmp_test load bad_not_null_term_target");

        strncmp_test__destroy(skel);
}

void test_test_strncmp(void)
{
        if (test__start_subtest("strncmp_ret"))
                test_strncmp_ret();
        if (test__start_subtest("strncmp_bad_not_const_str_size"))
                test_strncmp_bad_not_const_str_size();
        if (test__start_subtest("strncmp_bad_writable_target"))
                test_strncmp_bad_writable_target();
        if (test__start_subtest("strncmp_bad_not_null_term_target"))
                test_strncmp_bad_not_null_term_target();
}