// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
#include <errno.h>
#include <sys/syscall.h>
#include <unistd.h>
#include "test_global_map_resize.skel.h"
#include "test_progs.h"

static void run_prog_bss_array_sum(void)
{
        (void)syscall(__NR_getpid);
}

static void run_prog_data_array_sum(void)
{
        (void)syscall(__NR_getuid);
}

static void global_map_resize_bss_subtest(void)
{
        int err;
        struct test_global_map_resize *skel;
        struct bpf_map *map;
        const __u32 desired_sz = sizeof(skel->bss->sum) + sysconf(_SC_PAGE_SIZE) * 2;
        size_t array_len, actual_sz, new_sz;

        skel = test_global_map_resize__open();
        if (!ASSERT_OK_PTR(skel, "test_global_map_resize__open"))
                goto teardown;

        /* set some initial value before resizing.
         * it is expected this non-zero value will be preserved
         * while resizing.
         */
        skel->bss->array[0] = 1;

        /* resize map value and verify the new size */
        map = skel->maps.bss;
        err = bpf_map__set_value_size(map, desired_sz);
        if (!ASSERT_OK(err, "bpf_map__set_value_size"))
                goto teardown;
        if (!ASSERT_EQ(bpf_map__value_size(map), desired_sz, "resize"))
                goto teardown;

        new_sz = sizeof(skel->data_percpu_arr->percpu_arr[0]) * libbpf_num_possible_cpus();
        err = bpf_map__set_value_size(skel->maps.data_percpu_arr, new_sz);
        ASSERT_OK(err, "percpu_arr_resize");

        /* set the expected number of elements based on the resized array */
        array_len = (desired_sz - sizeof(skel->bss->sum)) / sizeof(skel->bss->array[0]);
        if (!ASSERT_GT(array_len, 1, "array_len"))
                goto teardown;

        skel->bss = bpf_map__initial_value(skel->maps.bss, &actual_sz);
        if (!ASSERT_OK_PTR(skel->bss, "bpf_map__initial_value (ptr)"))
                goto teardown;
        if (!ASSERT_EQ(actual_sz, desired_sz, "bpf_map__initial_value (size)"))
                goto teardown;

        /* fill the newly resized array with ones,
         * skipping the first element which was previously set
         */
        for (int i = 1; i < array_len; i++)
                skel->bss->array[i] = 1;

        /* set global const values before loading */
        skel->rodata->pid = getpid();
        skel->rodata->bss_array_len = array_len;
        skel->rodata->data_array_len = 1;

        err = test_global_map_resize__load(skel);
        if (!ASSERT_OK(err, "test_global_map_resize__load"))
                goto teardown;
        err = test_global_map_resize__attach(skel);
        if (!ASSERT_OK(err, "test_global_map_resize__attach"))
                goto teardown;

        /* run the bpf program which will sum the contents of the array.
         * since the array was filled with ones,verify the sum equals array_len
         */
        run_prog_bss_array_sum();
        if (!ASSERT_EQ(skel->bss->sum, array_len, "sum"))
                goto teardown;

teardown:
        test_global_map_resize__destroy(skel);
}

static void global_map_resize_data_subtest(void)
{
        struct test_global_map_resize *skel;
        struct bpf_map *map;
        const __u32 desired_sz = sysconf(_SC_PAGE_SIZE) * 2;
        size_t array_len, actual_sz, new_sz;
        int err;

        skel = test_global_map_resize__open();
        if (!ASSERT_OK_PTR(skel, "test_global_map_resize__open"))
                goto teardown;

        /* set some initial value before resizing.
         * it is expected this non-zero value will be preserved
         * while resizing.
         */
        skel->data_custom->my_array[0] = 1;

        /* resize map value and verify the new size */
        map = skel->maps.data_custom;
        err = bpf_map__set_value_size(map, desired_sz);
        if (!ASSERT_OK(err, "bpf_map__set_value_size"))
                goto teardown;
        if (!ASSERT_EQ(bpf_map__value_size(map), desired_sz, "resize"))
                goto teardown;

        new_sz = sizeof(skel->data_percpu_arr->percpu_arr[0]) * libbpf_num_possible_cpus();
        err = bpf_map__set_value_size(skel->maps.data_percpu_arr, new_sz);
        ASSERT_OK(err, "percpu_arr_resize");

        /* set the expected number of elements based on the resized array */
        array_len = (desired_sz - sizeof(skel->bss->sum)) / sizeof(skel->data_custom->my_array[0]);
        if (!ASSERT_GT(array_len, 1, "array_len"))
                goto teardown;

        skel->data_custom = bpf_map__initial_value(skel->maps.data_custom, &actual_sz);
        if (!ASSERT_OK_PTR(skel->data_custom, "bpf_map__initial_value (ptr)"))
                goto teardown;
        if (!ASSERT_EQ(actual_sz, desired_sz, "bpf_map__initial_value (size)"))
                goto teardown;

        /* fill the newly resized array with ones,
         * skipping the first element which was previously set
         */
        for (int i = 1; i < array_len; i++)
                skel->data_custom->my_array[i] = 1;

        /* set global const values before loading */
        skel->rodata->pid = getpid();
        skel->rodata->bss_array_len = 1;
        skel->rodata->data_array_len = array_len;

        err = test_global_map_resize__load(skel);
        if (!ASSERT_OK(err, "test_global_map_resize__load"))
                goto teardown;
        err = test_global_map_resize__attach(skel);
        if (!ASSERT_OK(err, "test_global_map_resize__attach"))
                goto teardown;

        /* run the bpf program which will sum the contents of the array.
         * since the array was filled with ones,verify the sum equals array_len
         */
        run_prog_data_array_sum();
        if (!ASSERT_EQ(skel->bss->sum, array_len, "sum"))
                goto teardown;

teardown:
        test_global_map_resize__destroy(skel);
}

static void global_map_resize_invalid_subtest(void)
{
        int err;
        struct test_global_map_resize *skel;
        struct bpf_map *map;
        __u32 element_sz, desired_sz;

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

         /* attempt to resize a global datasec map to size
          * which does NOT align with array
          */
        map = skel->maps.data_custom;
        if (!ASSERT_NEQ(bpf_map__btf_value_type_id(map), 0, ".data.custom initial btf"))
                goto teardown;
        /* set desired size a fraction of element size beyond an aligned size */
        element_sz = sizeof(skel->data_custom->my_array[0]);
        desired_sz = element_sz + element_sz / 2;
        /* confirm desired size does NOT align with array */
        if (!ASSERT_NEQ(desired_sz % element_sz, 0, "my_array alignment"))
                goto teardown;
        err = bpf_map__set_value_size(map, desired_sz);
        /* confirm resize is OK but BTF info is cleared */
        if (!ASSERT_OK(err, ".data.custom bpf_map__set_value_size") ||
            !ASSERT_EQ(bpf_map__btf_key_type_id(map), 0, ".data.custom clear btf key") ||
            !ASSERT_EQ(bpf_map__btf_value_type_id(map), 0, ".data.custom clear btf val"))
                goto teardown;

        /* attempt to resize a global datasec map whose only var is NOT an array */
        map = skel->maps.data_non_array;
        if (!ASSERT_NEQ(bpf_map__btf_value_type_id(map), 0, ".data.non_array initial btf"))
                goto teardown;
        /* set desired size to arbitrary value */
        desired_sz = 1024;
        err = bpf_map__set_value_size(map, desired_sz);
        /* confirm resize is OK but BTF info is cleared */
        if (!ASSERT_OK(err, ".data.non_array bpf_map__set_value_size") ||
            !ASSERT_EQ(bpf_map__btf_key_type_id(map), 0, ".data.non_array clear btf key") ||
            !ASSERT_EQ(bpf_map__btf_value_type_id(map), 0, ".data.non_array clear btf val"))
                goto teardown;

        /* attempt to resize a global datasec map
         * whose last var is NOT an array
         */
        map = skel->maps.data_array_not_last;
        if (!ASSERT_NEQ(bpf_map__btf_value_type_id(map), 0, ".data.array_not_last initial btf"))
                goto teardown;
        /* set desired size to a multiple of element size */
        element_sz = sizeof(skel->data_array_not_last->my_array_first[0]);
        desired_sz = element_sz * 8;
        /* confirm desired size aligns with array */
        if (!ASSERT_EQ(desired_sz % element_sz, 0, "my_array_first alignment"))
                goto teardown;
        err = bpf_map__set_value_size(map, desired_sz);
        /* confirm resize is OK but BTF info is cleared */
        if (!ASSERT_OK(err, ".data.array_not_last bpf_map__set_value_size") ||
            !ASSERT_EQ(bpf_map__btf_key_type_id(map), 0, ".data.array_not_last clear btf key") ||
            !ASSERT_EQ(bpf_map__btf_value_type_id(map), 0, ".data.array_not_last clear btf val"))
                goto teardown;

teardown:
        test_global_map_resize__destroy(skel);
}

void test_global_map_resize(void)
{
        if (test__start_subtest("global_map_resize_bss"))
                global_map_resize_bss_subtest();

        if (test__start_subtest("global_map_resize_data"))
                global_map_resize_data_subtest();

        if (test__start_subtest("global_map_resize_invalid"))
                global_map_resize_invalid_subtest();
}