// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2016 Facebook
 */
#define _GNU_SOURCE
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <assert.h>
#include <sched.h>
#include <stdlib.h>
#include <time.h>

#include <sys/wait.h>

#include <bpf/bpf.h>
#include <bpf/libbpf.h>

#include "bpf_util.h"
#include "bpf_rlimit.h"
#include "../../../include/linux/filter.h"

#define LOCAL_FREE_TARGET       (128)
#define PERCPU_FREE_TARGET      (4)

static int nr_cpus;

static int create_map(int map_type, int map_flags, unsigned int size)
{
        int map_fd;

        map_fd = bpf_create_map(map_type, sizeof(unsigned long long),
                                sizeof(unsigned long long), size, map_flags);

        if (map_fd == -1)
                perror("bpf_create_map");

        return map_fd;
}

static int bpf_map_lookup_elem_with_ref_bit(int fd, unsigned long long key,
                                            void *value)
{
        struct bpf_load_program_attr prog;
        struct bpf_create_map_attr map;
        struct bpf_insn insns[] = {
                BPF_LD_MAP_VALUE(BPF_REG_9, 0, 0),
                BPF_LD_MAP_FD(BPF_REG_1, fd),
                BPF_LD_IMM64(BPF_REG_3, key),
                BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
                BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
                BPF_STX_MEM(BPF_DW, BPF_REG_2, BPF_REG_3, 0),
                BPF_EMIT_CALL(BPF_FUNC_map_lookup_elem),
                BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4),
                BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, 0),
                BPF_STX_MEM(BPF_DW, BPF_REG_9, BPF_REG_1, 0),
                BPF_MOV64_IMM(BPF_REG_0, 42),
                BPF_JMP_IMM(BPF_JA, 0, 0, 1),
                BPF_MOV64_IMM(BPF_REG_0, 1),
                BPF_EXIT_INSN(),
        };
        __u8 data[64] = {};
        int mfd, pfd, ret, zero = 0;
        __u32 retval = 0;

        memset(&map, 0, sizeof(map));
        map.map_type = BPF_MAP_TYPE_ARRAY;
        map.key_size = sizeof(int);
        map.value_size = sizeof(unsigned long long);
        map.max_entries = 1;

        mfd = bpf_create_map_xattr(&map);
        if (mfd < 0)
                return -1;

        insns[0].imm = mfd;

        memset(&prog, 0, sizeof(prog));
        prog.prog_type = BPF_PROG_TYPE_SCHED_CLS;
        prog.insns = insns;
        prog.insns_cnt = ARRAY_SIZE(insns);
        prog.license = "GPL";

        pfd = bpf_load_program_xattr(&prog, NULL, 0);
        if (pfd < 0) {
                close(mfd);
                return -1;
        }

        ret = bpf_prog_test_run(pfd, 1, data, sizeof(data),
                                NULL, NULL, &retval, NULL);
        if (ret < 0 || retval != 42) {
                ret = -1;
        } else {
                assert(!bpf_map_lookup_elem(mfd, &zero, value));
                ret = 0;
        }
        close(pfd);
        close(mfd);
        return ret;
}

static int map_subset(int map0, int map1)
{
        unsigned long long next_key = 0;
        unsigned long long value0[nr_cpus], value1[nr_cpus];
        int ret;

        while (!bpf_map_get_next_key(map1, &next_key, &next_key)) {
                assert(!bpf_map_lookup_elem(map1, &next_key, value1));
                ret = bpf_map_lookup_elem(map0, &next_key, value0);
                if (ret) {
                        printf("key:%llu not found from map. %s(%d)\n",
                               next_key, strerror(errno), errno);
                        return 0;
                }
                if (value0[0] != value1[0]) {
                        printf("key:%llu value0:%llu != value1:%llu\n",
                               next_key, value0[0], value1[0]);
                        return 0;
                }
        }
        return 1;
}

static int map_equal(int lru_map, int expected)
{
        return map_subset(lru_map, expected) && map_subset(expected, lru_map);
}

static int sched_next_online(int pid, int *next_to_try)
{
        cpu_set_t cpuset;
        int next = *next_to_try;
        int ret = -1;

        while (next < nr_cpus) {
                CPU_ZERO(&cpuset);
                CPU_SET(next++, &cpuset);
                if (!sched_setaffinity(pid, sizeof(cpuset), &cpuset)) {
                        ret = 0;
                        break;
                }
        }

        *next_to_try = next;
        return ret;
}

/* Size of the LRU map is 2
 * Add key=1 (+1 key)
 * Add key=2 (+1 key)
 * Lookup Key=1
 * Add Key=3
 *   => Key=2 will be removed by LRU
 * Iterate map.  Only found key=1 and key=3
 */
static void test_lru_sanity0(int map_type, int map_flags)
{
        unsigned long long key, value[nr_cpus];
        int lru_map_fd, expected_map_fd;
        int next_cpu = 0;

        printf("%s (map_type:%d map_flags:0x%X): ", __func__, map_type,
               map_flags);

        assert(sched_next_online(0, &next_cpu) != -1);

        if (map_flags & BPF_F_NO_COMMON_LRU)
                lru_map_fd = create_map(map_type, map_flags, 2 * nr_cpus);
        else
                lru_map_fd = create_map(map_type, map_flags, 2);
        assert(lru_map_fd != -1);

        expected_map_fd = create_map(BPF_MAP_TYPE_HASH, 0, 2);
        assert(expected_map_fd != -1);

        value[0] = 1234;

        /* insert key=1 element */

        key = 1;
        assert(!bpf_map_update_elem(lru_map_fd, &key, value, BPF_NOEXIST));
        assert(!bpf_map_update_elem(expected_map_fd, &key, value,
                                    BPF_NOEXIST));

        /* BPF_NOEXIST means: add new element if it doesn't exist */
        assert(bpf_map_update_elem(lru_map_fd, &key, value, BPF_NOEXIST) == -1
               /* key=1 already exists */
               && errno == EEXIST);

        assert(bpf_map_update_elem(lru_map_fd, &key, value, -1) == -1 &&
               errno == EINVAL);

        /* insert key=2 element */

        /* check that key=2 is not found */
        key = 2;
        assert(bpf_map_lookup_elem(lru_map_fd, &key, value) == -1 &&
               errno == ENOENT);

        /* BPF_EXIST means: update existing element */
        assert(bpf_map_update_elem(lru_map_fd, &key, value, BPF_EXIST) == -1 &&
               /* key=2 is not there */
               errno == ENOENT);

        assert(!bpf_map_update_elem(lru_map_fd, &key, value, BPF_NOEXIST));

        /* insert key=3 element */

        /* check that key=3 is not found */
        key = 3;
        assert(bpf_map_lookup_elem(lru_map_fd, &key, value) == -1 &&
               errno == ENOENT);

        /* check that key=1 can be found and mark the ref bit to
         * stop LRU from removing key=1
         */
        key = 1;
        assert(!bpf_map_lookup_elem_with_ref_bit(lru_map_fd, key, value));
        assert(value[0] == 1234);

        key = 3;
        assert(!bpf_map_update_elem(lru_map_fd, &key, value, BPF_NOEXIST));
        assert(!bpf_map_update_elem(expected_map_fd, &key, value,
                                    BPF_NOEXIST));

        /* key=2 has been removed from the LRU */
        key = 2;
        assert(bpf_map_lookup_elem(lru_map_fd, &key, value) == -1 &&
               errno == ENOENT);

        /* lookup elem key=1 and delete it, then check it doesn't exist */
        key = 1;
        assert(!bpf_map_lookup_and_delete_elem(lru_map_fd, &key, &value));
        assert(value[0] == 1234);

        /* remove the same element from the expected map */
        assert(!bpf_map_delete_elem(expected_map_fd, &key));

        assert(map_equal(lru_map_fd, expected_map_fd));

        close(expected_map_fd);
        close(lru_map_fd);

        printf("Pass\n");
}

/* Size of the LRU map is 1.5*tgt_free
 * Insert 1 to tgt_free (+tgt_free keys)
 * Lookup 1 to tgt_free/2
 * Insert 1+tgt_free to 2*tgt_free (+tgt_free keys)
 * => 1+tgt_free/2 to LOCALFREE_TARGET will be removed by LRU
 */
static void test_lru_sanity1(int map_type, int map_flags, unsigned int tgt_free)
{
        unsigned long long key, end_key, value[nr_cpus];
        int lru_map_fd, expected_map_fd;
        unsigned int batch_size;
        unsigned int map_size;
        int next_cpu = 0;

        if (map_flags & BPF_F_NO_COMMON_LRU)
                /* This test is only applicable to common LRU list */
                return;

        printf("%s (map_type:%d map_flags:0x%X): ", __func__, map_type,
               map_flags);

        assert(sched_next_online(0, &next_cpu) != -1);

        batch_size = tgt_free / 2;
        assert(batch_size * 2 == tgt_free);

        map_size = tgt_free + batch_size;
        lru_map_fd = create_map(map_type, map_flags, map_size);
        assert(lru_map_fd != -1);

        expected_map_fd = create_map(BPF_MAP_TYPE_HASH, 0, map_size);
        assert(expected_map_fd != -1);

        value[0] = 1234;

        /* Insert 1 to tgt_free (+tgt_free keys) */
        end_key = 1 + tgt_free;
        for (key = 1; key < end_key; key++)
                assert(!bpf_map_update_elem(lru_map_fd, &key, value,
                                            BPF_NOEXIST));

        /* Lookup 1 to tgt_free/2 */
        end_key = 1 + batch_size;
        for (key = 1; key < end_key; key++) {
                assert(!bpf_map_lookup_elem_with_ref_bit(lru_map_fd, key, value));
                assert(!bpf_map_update_elem(expected_map_fd, &key, value,
                                            BPF_NOEXIST));
        }

        /* Insert 1+tgt_free to 2*tgt_free
         * => 1+tgt_free/2 to LOCALFREE_TARGET will be
         * removed by LRU
         */
        key = 1 + tgt_free;
        end_key = key + tgt_free;
        for (; key < end_key; key++) {
                assert(!bpf_map_update_elem(lru_map_fd, &key, value,
                                            BPF_NOEXIST));
                assert(!bpf_map_update_elem(expected_map_fd, &key, value,
                                            BPF_NOEXIST));
        }

        assert(map_equal(lru_map_fd, expected_map_fd));

        close(expected_map_fd);
        close(lru_map_fd);

        printf("Pass\n");
}

/* Size of the LRU map 1.5 * tgt_free
 * Insert 1 to tgt_free (+tgt_free keys)
 * Update 1 to tgt_free/2
 *   => The original 1 to tgt_free/2 will be removed due to
 *      the LRU shrink process
 * Re-insert 1 to tgt_free/2 again and do a lookup immeidately
 * Insert 1+tgt_free to tgt_free*3/2
 * Insert 1+tgt_free*3/2 to tgt_free*5/2
 *   => Key 1+tgt_free to tgt_free*3/2
 *      will be removed from LRU because it has never
 *      been lookup and ref bit is not set
 */
static void test_lru_sanity2(int map_type, int map_flags, unsigned int tgt_free)
{
        unsigned long long key, value[nr_cpus];
        unsigned long long end_key;
        int lru_map_fd, expected_map_fd;
        unsigned int batch_size;
        unsigned int map_size;
        int next_cpu = 0;

        if (map_flags & BPF_F_NO_COMMON_LRU)
                /* This test is only applicable to common LRU list */
                return;

        printf("%s (map_type:%d map_flags:0x%X): ", __func__, map_type,
               map_flags);

        assert(sched_next_online(0, &next_cpu) != -1);

        batch_size = tgt_free / 2;
        assert(batch_size * 2 == tgt_free);

        map_size = tgt_free + batch_size;
        lru_map_fd = create_map(map_type, map_flags, map_size);
        assert(lru_map_fd != -1);

        expected_map_fd = create_map(BPF_MAP_TYPE_HASH, 0, map_size);
        assert(expected_map_fd != -1);

        value[0] = 1234;

        /* Insert 1 to tgt_free (+tgt_free keys) */
        end_key = 1 + tgt_free;
        for (key = 1; key < end_key; key++)
                assert(!bpf_map_update_elem(lru_map_fd, &key, value,
                                            BPF_NOEXIST));

        /* Any bpf_map_update_elem will require to acquire a new node
         * from LRU first.
         *
         * The local list is running out of free nodes.
         * It gets from the global LRU list which tries to
         * shrink the inactive list to get tgt_free
         * number of free nodes.
         *
         * Hence, the oldest key 1 to tgt_free/2
         * are removed from the LRU list.
         */
        key = 1;
        if (map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) {
                assert(!bpf_map_update_elem(lru_map_fd, &key, value,
                                            BPF_NOEXIST));
                assert(!bpf_map_delete_elem(lru_map_fd, &key));
        } else {
                assert(bpf_map_update_elem(lru_map_fd, &key, value,
                                           BPF_EXIST));
        }

        /* Re-insert 1 to tgt_free/2 again and do a lookup
         * immeidately.
         */
        end_key = 1 + batch_size;
        value[0] = 4321;
        for (key = 1; key < end_key; key++) {
                assert(bpf_map_lookup_elem(lru_map_fd, &key, value) == -1 &&
                       errno == ENOENT);
                assert(!bpf_map_update_elem(lru_map_fd, &key, value,
                                            BPF_NOEXIST));
                assert(!bpf_map_lookup_elem_with_ref_bit(lru_map_fd, key, value));
                assert(value[0] == 4321);
                assert(!bpf_map_update_elem(expected_map_fd, &key, value,
                                            BPF_NOEXIST));
        }

        value[0] = 1234;

        /* Insert 1+tgt_free to tgt_free*3/2 */
        end_key = 1 + tgt_free + batch_size;
        for (key = 1 + tgt_free; key < end_key; key++)
                /* These newly added but not referenced keys will be
                 * gone during the next LRU shrink.
                 */
                assert(!bpf_map_update_elem(lru_map_fd, &key, value,
                                            BPF_NOEXIST));

        /* Insert 1+tgt_free*3/2 to  tgt_free*5/2 */
        end_key = key + tgt_free;
        for (; key < end_key; key++) {
                assert(!bpf_map_update_elem(lru_map_fd, &key, value,
                                            BPF_NOEXIST));
                assert(!bpf_map_update_elem(expected_map_fd, &key, value,
                                            BPF_NOEXIST));
        }

        assert(map_equal(lru_map_fd, expected_map_fd));

        close(expected_map_fd);
        close(lru_map_fd);

        printf("Pass\n");
}

/* Size of the LRU map is 2*tgt_free
 * It is to test the active/inactive list rotation
 * Insert 1 to 2*tgt_free (+2*tgt_free keys)
 * Lookup key 1 to tgt_free*3/2
 * Add 1+2*tgt_free to tgt_free*5/2 (+tgt_free/2 keys)
 *  => key 1+tgt_free*3/2 to 2*tgt_free are removed from LRU
 */
static void test_lru_sanity3(int map_type, int map_flags, unsigned int tgt_free)
{
        unsigned long long key, end_key, value[nr_cpus];
        int lru_map_fd, expected_map_fd;
        unsigned int batch_size;
        unsigned int map_size;
        int next_cpu = 0;

        if (map_flags & BPF_F_NO_COMMON_LRU)
                /* This test is only applicable to common LRU list */
                return;

        printf("%s (map_type:%d map_flags:0x%X): ", __func__, map_type,
               map_flags);

        assert(sched_next_online(0, &next_cpu) != -1);

        batch_size = tgt_free / 2;
        assert(batch_size * 2 == tgt_free);

        map_size = tgt_free * 2;
        lru_map_fd = create_map(map_type, map_flags, map_size);
        assert(lru_map_fd != -1);

        expected_map_fd = create_map(BPF_MAP_TYPE_HASH, 0, map_size);
        assert(expected_map_fd != -1);

        value[0] = 1234;

        /* Insert 1 to 2*tgt_free (+2*tgt_free keys) */
        end_key = 1 + (2 * tgt_free);
        for (key = 1; key < end_key; key++)
                assert(!bpf_map_update_elem(lru_map_fd, &key, value,
                                            BPF_NOEXIST));

        /* Lookup key 1 to tgt_free*3/2 */
        end_key = tgt_free + batch_size;
        for (key = 1; key < end_key; key++) {
                assert(!bpf_map_lookup_elem_with_ref_bit(lru_map_fd, key, value));
                assert(!bpf_map_update_elem(expected_map_fd, &key, value,
                                            BPF_NOEXIST));
        }

        /* Add 1+2*tgt_free to tgt_free*5/2
         * (+tgt_free/2 keys)
         */
        key = 2 * tgt_free + 1;
        end_key = key + batch_size;
        for (; key < end_key; key++) {
                assert(!bpf_map_update_elem(lru_map_fd, &key, value,
                                            BPF_NOEXIST));
                assert(!bpf_map_update_elem(expected_map_fd, &key, value,
                                            BPF_NOEXIST));
        }

        assert(map_equal(lru_map_fd, expected_map_fd));

        close(expected_map_fd);
        close(lru_map_fd);

        printf("Pass\n");
}

/* Test deletion */
static void test_lru_sanity4(int map_type, int map_flags, unsigned int tgt_free)
{
        int lru_map_fd, expected_map_fd;
        unsigned long long key, value[nr_cpus];
        unsigned long long end_key;
        int next_cpu = 0;

        printf("%s (map_type:%d map_flags:0x%X): ", __func__, map_type,
               map_flags);

        assert(sched_next_online(0, &next_cpu) != -1);

        if (map_flags & BPF_F_NO_COMMON_LRU)
                lru_map_fd = create_map(map_type, map_flags,
                                        3 * tgt_free * nr_cpus);
        else
                lru_map_fd = create_map(map_type, map_flags, 3 * tgt_free);
        assert(lru_map_fd != -1);

        expected_map_fd = create_map(BPF_MAP_TYPE_HASH, 0,
                                     3 * tgt_free);
        assert(expected_map_fd != -1);

        value[0] = 1234;

        for (key = 1; key <= 2 * tgt_free; key++)
                assert(!bpf_map_update_elem(lru_map_fd, &key, value,
                                            BPF_NOEXIST));

        key = 1;
        assert(bpf_map_update_elem(lru_map_fd, &key, value, BPF_NOEXIST));

        for (key = 1; key <= tgt_free; key++) {
                assert(!bpf_map_lookup_elem_with_ref_bit(lru_map_fd, key, value));
                assert(!bpf_map_update_elem(expected_map_fd, &key, value,
                                            BPF_NOEXIST));
        }

        for (; key <= 2 * tgt_free; key++) {
                assert(!bpf_map_delete_elem(lru_map_fd, &key));
                assert(bpf_map_delete_elem(lru_map_fd, &key));
        }

        end_key = key + 2 * tgt_free;
        for (; key < end_key; key++) {
                assert(!bpf_map_update_elem(lru_map_fd, &key, value,
                                            BPF_NOEXIST));
                assert(!bpf_map_update_elem(expected_map_fd, &key, value,
                                            BPF_NOEXIST));
        }

        assert(map_equal(lru_map_fd, expected_map_fd));

        close(expected_map_fd);
        close(lru_map_fd);

        printf("Pass\n");
}

static void do_test_lru_sanity5(unsigned long long last_key, int map_fd)
{
        unsigned long long key, value[nr_cpus];

        /* Ensure the last key inserted by previous CPU can be found */
        assert(!bpf_map_lookup_elem_with_ref_bit(map_fd, last_key, value));
        value[0] = 1234;

        key = last_key + 1;
        assert(!bpf_map_update_elem(map_fd, &key, value, BPF_NOEXIST));
        assert(!bpf_map_lookup_elem_with_ref_bit(map_fd, key, value));

        /* Cannot find the last key because it was removed by LRU */
        assert(bpf_map_lookup_elem(map_fd, &last_key, value) == -1 &&
               errno == ENOENT);
}

/* Test map with only one element */
static void test_lru_sanity5(int map_type, int map_flags)
{
        unsigned long long key, value[nr_cpus];
        int next_cpu = 0;
        int map_fd;

        if (map_flags & BPF_F_NO_COMMON_LRU)
                return;

        printf("%s (map_type:%d map_flags:0x%X): ", __func__, map_type,
               map_flags);

        map_fd = create_map(map_type, map_flags, 1);
        assert(map_fd != -1);

        value[0] = 1234;
        key = 0;
        assert(!bpf_map_update_elem(map_fd, &key, value, BPF_NOEXIST));

        while (sched_next_online(0, &next_cpu) != -1) {
                pid_t pid;

                pid = fork();
                if (pid == 0) {
                        do_test_lru_sanity5(key, map_fd);
                        exit(0);
                } else if (pid == -1) {
                        printf("couldn't spawn process to test key:%llu\n",
                               key);
                        exit(1);
                } else {
                        int status;

                        assert(waitpid(pid, &status, 0) == pid);
                        assert(status == 0);
                        key++;
                }
        }

        close(map_fd);
        /* At least one key should be tested */
        assert(key > 0);

        printf("Pass\n");
}

/* Test list rotation for BPF_F_NO_COMMON_LRU map */
static void test_lru_sanity6(int map_type, int map_flags, int tgt_free)
{
        int lru_map_fd, expected_map_fd;
        unsigned long long key, value[nr_cpus];
        unsigned int map_size = tgt_free * 2;
        int next_cpu = 0;

        if (!(map_flags & BPF_F_NO_COMMON_LRU))
                return;

        printf("%s (map_type:%d map_flags:0x%X): ", __func__, map_type,
               map_flags);

        assert(sched_next_online(0, &next_cpu) != -1);

        expected_map_fd = create_map(BPF_MAP_TYPE_HASH, 0, map_size);
        assert(expected_map_fd != -1);

        lru_map_fd = create_map(map_type, map_flags, map_size * nr_cpus);
        assert(lru_map_fd != -1);

        value[0] = 1234;

        for (key = 1; key <= tgt_free; key++) {
                assert(!bpf_map_update_elem(lru_map_fd, &key, value,
                                            BPF_NOEXIST));
                assert(!bpf_map_update_elem(expected_map_fd, &key, value,
                                            BPF_NOEXIST));
        }

        for (; key <= tgt_free * 2; key++) {
                unsigned long long stable_key;

                /* Make ref bit sticky for key: [1, tgt_free] */
                for (stable_key = 1; stable_key <= tgt_free; stable_key++) {
                        /* Mark the ref bit */
                        assert(!bpf_map_lookup_elem_with_ref_bit(lru_map_fd,
                                                                 stable_key, value));
                }
                assert(!bpf_map_update_elem(lru_map_fd, &key, value,
                                            BPF_NOEXIST));
        }

        for (; key <= tgt_free * 3; key++) {
                assert(!bpf_map_update_elem(lru_map_fd, &key, value,
                                            BPF_NOEXIST));
                assert(!bpf_map_update_elem(expected_map_fd, &key, value,
                                            BPF_NOEXIST));
        }

        assert(map_equal(lru_map_fd, expected_map_fd));

        close(expected_map_fd);
        close(lru_map_fd);

        printf("Pass\n");
}

/* Size of the LRU map is 2
 * Add key=1 (+1 key)
 * Add key=2 (+1 key)
 * Lookup Key=1 (datapath)
 * Lookup Key=2 (syscall)
 * Add Key=3
 *   => Key=2 will be removed by LRU
 * Iterate map.  Only found key=1 and key=3
 */
static void test_lru_sanity7(int map_type, int map_flags)
{
        unsigned long long key, value[nr_cpus];
        int lru_map_fd, expected_map_fd;
        int next_cpu = 0;

        printf("%s (map_type:%d map_flags:0x%X): ", __func__, map_type,
               map_flags);

        assert(sched_next_online(0, &next_cpu) != -1);

        if (map_flags & BPF_F_NO_COMMON_LRU)
                lru_map_fd = create_map(map_type, map_flags, 2 * nr_cpus);
        else
                lru_map_fd = create_map(map_type, map_flags, 2);
        assert(lru_map_fd != -1);

        expected_map_fd = create_map(BPF_MAP_TYPE_HASH, 0, 2);
        assert(expected_map_fd != -1);

        value[0] = 1234;

        /* insert key=1 element */

        key = 1;
        assert(!bpf_map_update_elem(lru_map_fd, &key, value, BPF_NOEXIST));
        assert(!bpf_map_update_elem(expected_map_fd, &key, value,
                                    BPF_NOEXIST));

        /* BPF_NOEXIST means: add new element if it doesn't exist */
        assert(bpf_map_update_elem(lru_map_fd, &key, value, BPF_NOEXIST) == -1
               /* key=1 already exists */
               && errno == EEXIST);

        /* insert key=2 element */

        /* check that key=2 is not found */
        key = 2;
        assert(bpf_map_lookup_elem(lru_map_fd, &key, value) == -1 &&
               errno == ENOENT);

        /* BPF_EXIST means: update existing element */
        assert(bpf_map_update_elem(lru_map_fd, &key, value, BPF_EXIST) == -1 &&
               /* key=2 is not there */
               errno == ENOENT);

        assert(!bpf_map_update_elem(lru_map_fd, &key, value, BPF_NOEXIST));

        /* insert key=3 element */

        /* check that key=3 is not found */
        key = 3;
        assert(bpf_map_lookup_elem(lru_map_fd, &key, value) == -1 &&
               errno == ENOENT);

        /* check that key=1 can be found and mark the ref bit to
         * stop LRU from removing key=1
         */
        key = 1;
        assert(!bpf_map_lookup_elem_with_ref_bit(lru_map_fd, key, value));
        assert(value[0] == 1234);

        /* check that key=2 can be found and do _not_ mark ref bit.
         * this will be evicted on next update.
         */
        key = 2;
        assert(!bpf_map_lookup_elem(lru_map_fd, &key, value));
        assert(value[0] == 1234);

        key = 3;
        assert(!bpf_map_update_elem(lru_map_fd, &key, value, BPF_NOEXIST));
        assert(!bpf_map_update_elem(expected_map_fd, &key, value,
                                    BPF_NOEXIST));

        /* key=2 has been removed from the LRU */
        key = 2;
        assert(bpf_map_lookup_elem(lru_map_fd, &key, value) == -1 &&
               errno == ENOENT);

        assert(map_equal(lru_map_fd, expected_map_fd));

        close(expected_map_fd);
        close(lru_map_fd);

        printf("Pass\n");
}

/* Size of the LRU map is 2
 * Add key=1 (+1 key)
 * Add key=2 (+1 key)
 * Lookup Key=1 (syscall)
 * Lookup Key=2 (datapath)
 * Add Key=3
 *   => Key=1 will be removed by LRU
 * Iterate map.  Only found key=2 and key=3
 */
static void test_lru_sanity8(int map_type, int map_flags)
{
        unsigned long long key, value[nr_cpus];
        int lru_map_fd, expected_map_fd;
        int next_cpu = 0;

        printf("%s (map_type:%d map_flags:0x%X): ", __func__, map_type,
               map_flags);

        assert(sched_next_online(0, &next_cpu) != -1);

        if (map_flags & BPF_F_NO_COMMON_LRU)
                lru_map_fd = create_map(map_type, map_flags, 2 * nr_cpus);
        else
                lru_map_fd = create_map(map_type, map_flags, 2);
        assert(lru_map_fd != -1);

        expected_map_fd = create_map(BPF_MAP_TYPE_HASH, 0, 2);
        assert(expected_map_fd != -1);

        value[0] = 1234;

        /* insert key=1 element */

        key = 1;
        assert(!bpf_map_update_elem(lru_map_fd, &key, value, BPF_NOEXIST));

        /* BPF_NOEXIST means: add new element if it doesn't exist */
        assert(bpf_map_update_elem(lru_map_fd, &key, value, BPF_NOEXIST) == -1
               /* key=1 already exists */
               && errno == EEXIST);

        /* insert key=2 element */

        /* check that key=2 is not found */
        key = 2;
        assert(bpf_map_lookup_elem(lru_map_fd, &key, value) == -1 &&
               errno == ENOENT);

        /* BPF_EXIST means: update existing element */
        assert(bpf_map_update_elem(lru_map_fd, &key, value, BPF_EXIST) == -1 &&
               /* key=2 is not there */
               errno == ENOENT);

        assert(!bpf_map_update_elem(lru_map_fd, &key, value, BPF_NOEXIST));
        assert(!bpf_map_update_elem(expected_map_fd, &key, value,
                                    BPF_NOEXIST));

        /* insert key=3 element */

        /* check that key=3 is not found */
        key = 3;
        assert(bpf_map_lookup_elem(lru_map_fd, &key, value) == -1 &&
               errno == ENOENT);

        /* check that key=1 can be found and do _not_ mark ref bit.
         * this will be evicted on next update.
         */
        key = 1;
        assert(!bpf_map_lookup_elem(lru_map_fd, &key, value));
        assert(value[0] == 1234);

        /* check that key=2 can be found and mark the ref bit to
         * stop LRU from removing key=2
         */
        key = 2;
        assert(!bpf_map_lookup_elem_with_ref_bit(lru_map_fd, key, value));
        assert(value[0] == 1234);

        key = 3;
        assert(!bpf_map_update_elem(lru_map_fd, &key, value, BPF_NOEXIST));
        assert(!bpf_map_update_elem(expected_map_fd, &key, value,
                                    BPF_NOEXIST));

        /* key=1 has been removed from the LRU */
        key = 1;
        assert(bpf_map_lookup_elem(lru_map_fd, &key, value) == -1 &&
               errno == ENOENT);

        assert(map_equal(lru_map_fd, expected_map_fd));

        close(expected_map_fd);
        close(lru_map_fd);

        printf("Pass\n");
}

int main(int argc, char **argv)
{
        int map_types[] = {BPF_MAP_TYPE_LRU_HASH,
                             BPF_MAP_TYPE_LRU_PERCPU_HASH};
        int map_flags[] = {0, BPF_F_NO_COMMON_LRU};
        int t, f;

        setbuf(stdout, NULL);

        nr_cpus = bpf_num_possible_cpus();
        assert(nr_cpus != -1);
        printf("nr_cpus:%d\n\n", nr_cpus);

        for (f = 0; f < sizeof(map_flags) / sizeof(*map_flags); f++) {
                unsigned int tgt_free = (map_flags[f] & BPF_F_NO_COMMON_LRU) ?
                        PERCPU_FREE_TARGET : LOCAL_FREE_TARGET;

                for (t = 0; t < sizeof(map_types) / sizeof(*map_types); t++) {
                        test_lru_sanity0(map_types[t], map_flags[f]);
                        test_lru_sanity1(map_types[t], map_flags[f], tgt_free);
                        test_lru_sanity2(map_types[t], map_flags[f], tgt_free);
                        test_lru_sanity3(map_types[t], map_flags[f], tgt_free);
                        test_lru_sanity4(map_types[t], map_flags[f], tgt_free);
                        test_lru_sanity5(map_types[t], map_flags[f]);
                        test_lru_sanity6(map_types[t], map_flags[f], tgt_free);
                        test_lru_sanity7(map_types[t], map_flags[f]);
                        test_lru_sanity8(map_types[t], map_flags[f]);

                        printf("\n");
                }
        }

        return 0;
}