// SPDX-License-Identifier: GPL-2.0
#include <assert.h>
#include <bpf/bpf.h>
#include <linux/filter.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/sysinfo.h>

#include "bpf_rlimit.h"
#include "cgroup_helpers.h"

char bpf_log_buf[BPF_LOG_BUF_SIZE];

#define TEST_CGROUP "/test-bpf-cgroup-storage-buf/"

int main(int argc, char **argv)
{
        struct bpf_insn prog[] = {
                BPF_LD_MAP_FD(BPF_REG_1, 0), /* percpu map fd */
                BPF_MOV64_IMM(BPF_REG_2, 0), /* flags, not used */
                BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
                             BPF_FUNC_get_local_storage),
                BPF_LDX_MEM(BPF_DW, BPF_REG_3, BPF_REG_0, 0),
                BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, 0x1),
                BPF_STX_MEM(BPF_DW, BPF_REG_0, BPF_REG_3, 0),

                BPF_LD_MAP_FD(BPF_REG_1, 0), /* map fd */
                BPF_MOV64_IMM(BPF_REG_2, 0), /* flags, not used */
                BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
                             BPF_FUNC_get_local_storage),
                BPF_MOV64_IMM(BPF_REG_1, 1),
                BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_0, BPF_REG_1, 0),
                BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, 0),
                BPF_ALU64_IMM(BPF_AND, BPF_REG_1, 0x1),
                BPF_MOV64_REG(BPF_REG_0, BPF_REG_1),
                BPF_EXIT_INSN(),
        };
        size_t insns_cnt = sizeof(prog) / sizeof(struct bpf_insn);
        int error = EXIT_FAILURE;
        int map_fd, percpu_map_fd, prog_fd, cgroup_fd;
        struct bpf_cgroup_storage_key key;
        unsigned long long value;
        unsigned long long *percpu_value;
        int cpu, nproc;

        nproc = get_nprocs_conf();
        percpu_value = malloc(sizeof(*percpu_value) * nproc);
        if (!percpu_value) {
                printf("Not enough memory for per-cpu area (%d cpus)\n", nproc);
                goto err;
        }

        map_fd = bpf_create_map(BPF_MAP_TYPE_CGROUP_STORAGE, sizeof(key),
                                sizeof(value), 0, 0);
        if (map_fd < 0) {
                printf("Failed to create map: %s\n", strerror(errno));
                goto out;
        }

        percpu_map_fd = bpf_create_map(BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE,
                                       sizeof(key), sizeof(value), 0, 0);
        if (percpu_map_fd < 0) {
                printf("Failed to create map: %s\n", strerror(errno));
                goto out;
        }

        prog[0].imm = percpu_map_fd;
        prog[7].imm = map_fd;
        prog_fd = bpf_load_program(BPF_PROG_TYPE_CGROUP_SKB,
                                   prog, insns_cnt, "GPL", 0,
                                   bpf_log_buf, BPF_LOG_BUF_SIZE);
        if (prog_fd < 0) {
                printf("Failed to load bpf program: %s\n", bpf_log_buf);
                goto out;
        }

        cgroup_fd = cgroup_setup_and_join(TEST_CGROUP);

        /* Attach the bpf program */
        if (bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_INET_EGRESS, 0)) {
                printf("Failed to attach bpf program\n");
                goto err;
        }

        if (bpf_map_get_next_key(map_fd, NULL, &key)) {
                printf("Failed to get the first key in cgroup storage\n");
                goto err;
        }

        if (bpf_map_lookup_elem(map_fd, &key, &value)) {
                printf("Failed to lookup cgroup storage 0\n");
                goto err;
        }

        for (cpu = 0; cpu < nproc; cpu++)
                percpu_value[cpu] = 1000;

        if (bpf_map_update_elem(percpu_map_fd, &key, percpu_value, 0)) {
                printf("Failed to update the data in the cgroup storage\n");
                goto err;
        }

        /* Every second packet should be dropped */
        assert(system("ping localhost -c 1 -W 1 -q > /dev/null") == 0);
        assert(system("ping localhost -c 1 -W 1 -q > /dev/null"));
        assert(system("ping localhost -c 1 -W 1 -q > /dev/null") == 0);

        /* Check the counter in the cgroup local storage */
        if (bpf_map_lookup_elem(map_fd, &key, &value)) {
                printf("Failed to lookup cgroup storage\n");
                goto err;
        }

        if (value != 3) {
                printf("Unexpected data in the cgroup storage: %llu\n", value);
                goto err;
        }

        /* Bump the counter in the cgroup local storage */
        value++;
        if (bpf_map_update_elem(map_fd, &key, &value, 0)) {
                printf("Failed to update the data in the cgroup storage\n");
                goto err;
        }

        /* Every second packet should be dropped */
        assert(system("ping localhost -c 1 -W 1 -q > /dev/null") == 0);
        assert(system("ping localhost -c 1 -W 1 -q > /dev/null"));
        assert(system("ping localhost -c 1 -W 1 -q > /dev/null") == 0);

        /* Check the final value of the counter in the cgroup local storage */
        if (bpf_map_lookup_elem(map_fd, &key, &value)) {
                printf("Failed to lookup the cgroup storage\n");
                goto err;
        }

        if (value != 7) {
                printf("Unexpected data in the cgroup storage: %llu\n", value);
                goto err;
        }

        /* Check the final value of the counter in the percpu local storage */

        for (cpu = 0; cpu < nproc; cpu++)
                percpu_value[cpu] = 0;

        if (bpf_map_lookup_elem(percpu_map_fd, &key, percpu_value)) {
                printf("Failed to lookup the per-cpu cgroup storage\n");
                goto err;
        }

        value = 0;
        for (cpu = 0; cpu < nproc; cpu++)
                value += percpu_value[cpu];

        if (value != nproc * 1000 + 6) {
                printf("Unexpected data in the per-cpu cgroup storage\n");
                goto err;
        }

        error = 0;
        printf("test_cgroup_storage:PASS\n");

err:
        cleanup_cgroup_environment();
        free(percpu_value);

out:
        return error;
}