// SPDX-License-Identifier: GPL-2.0
/*
 * Randomized tests for eBPF longest-prefix-match maps
 *
 * This program runs randomized tests against the lpm-bpf-map. It implements a
 * "Trivial Longest Prefix Match" (tlpm) based on simple, linear, singly linked
 * lists. The implementation should be pretty straightforward.
 *
 * Based on tlpm, this inserts randomized data into bpf-lpm-maps and verifies
 * the trie-based bpf-map implementation behaves the same way as tlpm.
 */

#include <assert.h>
#include <errno.h>
#include <inttypes.h>
#include <linux/bpf.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <endian.h>
#include <arpa/inet.h>
#include <sys/time.h>

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

#include "bpf_util.h"

struct tlpm_node {
        struct tlpm_node *next;
        size_t n_bits;
        uint8_t key[];
};

struct lpm_trie_bytes_key {
        union {
                struct bpf_lpm_trie_key_hdr hdr;
                __u32 prefixlen;
        };
        unsigned char data[8];
};

struct lpm_trie_int_key {
        union {
                struct bpf_lpm_trie_key_hdr hdr;
                __u32 prefixlen;
        };
        unsigned int data;
};

static struct tlpm_node *tlpm_match(struct tlpm_node *list,
                                    const uint8_t *key,
                                    size_t n_bits);

static struct tlpm_node *tlpm_add(struct tlpm_node *list,
                                  const uint8_t *key,
                                  size_t n_bits)
{
        struct tlpm_node *node;
        size_t n;

        n = (n_bits + 7) / 8;

        /* 'overwrite' an equivalent entry if one already exists */
        node = tlpm_match(list, key, n_bits);
        if (node && node->n_bits == n_bits) {
                memcpy(node->key, key, n);
                return list;
        }

        /* add new entry with @key/@n_bits to @list and return new head */

        node = malloc(sizeof(*node) + n);
        assert(node);

        node->next = list;
        node->n_bits = n_bits;
        memcpy(node->key, key, n);

        return node;
}

static void tlpm_clear(struct tlpm_node *list)
{
        struct tlpm_node *node;

        /* free all entries in @list */

        while ((node = list)) {
                list = list->next;
                free(node);
        }
}

static struct tlpm_node *tlpm_match(struct tlpm_node *list,
                                    const uint8_t *key,
                                    size_t n_bits)
{
        struct tlpm_node *best = NULL;
        size_t i;

        /* Perform longest prefix-match on @key/@n_bits. That is, iterate all
         * entries and match each prefix against @key. Remember the "best"
         * entry we find (i.e., the longest prefix that matches) and return it
         * to the caller when done.
         */

        for ( ; list; list = list->next) {
                for (i = 0; i < n_bits && i < list->n_bits; ++i) {
                        if ((key[i / 8] & (1 << (7 - i % 8))) !=
                            (list->key[i / 8] & (1 << (7 - i % 8))))
                                break;
                }

                if (i >= list->n_bits) {
                        if (!best || i > best->n_bits)
                                best = list;
                }
        }

        return best;
}

static struct tlpm_node *tlpm_delete(struct tlpm_node *list,
                                     const uint8_t *key,
                                     size_t n_bits)
{
        struct tlpm_node *best = tlpm_match(list, key, n_bits);
        struct tlpm_node *node;

        if (!best || best->n_bits != n_bits)
                return list;

        if (best == list) {
                node = best->next;
                free(best);
                return node;
        }

        for (node = list; node; node = node->next) {
                if (node->next == best) {
                        node->next = best->next;
                        free(best);
                        return list;
                }
        }
        /* should never get here */
        assert(0);
        return list;
}

static void test_lpm_basic(void)
{
        struct tlpm_node *list = NULL, *t1, *t2;

        /* very basic, static tests to verify tlpm works as expected */

        assert(!tlpm_match(list, (uint8_t[]){ 0xff }, 8));

        t1 = list = tlpm_add(list, (uint8_t[]){ 0xff }, 8);
        assert(t1 == tlpm_match(list, (uint8_t[]){ 0xff }, 8));
        assert(t1 == tlpm_match(list, (uint8_t[]){ 0xff, 0xff }, 16));
        assert(t1 == tlpm_match(list, (uint8_t[]){ 0xff, 0x00 }, 16));
        assert(!tlpm_match(list, (uint8_t[]){ 0x7f }, 8));
        assert(!tlpm_match(list, (uint8_t[]){ 0xfe }, 8));
        assert(!tlpm_match(list, (uint8_t[]){ 0xff }, 7));

        t2 = list = tlpm_add(list, (uint8_t[]){ 0xff, 0xff }, 16);
        assert(t1 == tlpm_match(list, (uint8_t[]){ 0xff }, 8));
        assert(t2 == tlpm_match(list, (uint8_t[]){ 0xff, 0xff }, 16));
        assert(t1 == tlpm_match(list, (uint8_t[]){ 0xff, 0xff }, 15));
        assert(!tlpm_match(list, (uint8_t[]){ 0x7f, 0xff }, 16));

        list = tlpm_delete(list, (uint8_t[]){ 0xff, 0xff }, 16);
        assert(t1 == tlpm_match(list, (uint8_t[]){ 0xff }, 8));
        assert(t1 == tlpm_match(list, (uint8_t[]){ 0xff, 0xff }, 16));

        list = tlpm_delete(list, (uint8_t[]){ 0xff }, 8);
        assert(!tlpm_match(list, (uint8_t[]){ 0xff }, 8));

        tlpm_clear(list);
}

static void test_lpm_order(void)
{
        struct tlpm_node *t1, *t2, *l1 = NULL, *l2 = NULL;
        size_t i, j;

        /* Verify the tlpm implementation works correctly regardless of the
         * order of entries. Insert a random set of entries into @l1, and copy
         * the same data in reverse order into @l2. Then verify a lookup of
         * random keys will yield the same result in both sets.
         */

        for (i = 0; i < (1 << 12); ++i)
                l1 = tlpm_add(l1, (uint8_t[]){
                                        rand() % 0xff,
                                        rand() % 0xff,
                                }, rand() % 16 + 1);

        for (t1 = l1; t1; t1 = t1->next)
                l2 = tlpm_add(l2, t1->key, t1->n_bits);

        for (i = 0; i < (1 << 8); ++i) {
                uint8_t key[] = { rand() % 0xff, rand() % 0xff };

                t1 = tlpm_match(l1, key, 16);
                t2 = tlpm_match(l2, key, 16);

                assert(!t1 == !t2);
                if (t1) {
                        assert(t1->n_bits == t2->n_bits);
                        for (j = 0; j < t1->n_bits; ++j)
                                assert((t1->key[j / 8] & (1 << (7 - j % 8))) ==
                                       (t2->key[j / 8] & (1 << (7 - j % 8))));
                }
        }

        tlpm_clear(l1);
        tlpm_clear(l2);
}

static void test_lpm_map(int keysize)
{
        LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_NO_PREALLOC);
        volatile size_t n_matches, n_matches_after_delete;
        size_t i, j, n_nodes, n_lookups;
        struct tlpm_node *t, *list = NULL;
        struct bpf_lpm_trie_key_u8 *key;
        uint8_t *data, *value;
        int r, map;

        /* Compare behavior of tlpm vs. bpf-lpm. Create a randomized set of
         * prefixes and insert it into both tlpm and bpf-lpm. Then run some
         * randomized lookups and verify both maps return the same result.
         */

        n_matches = 0;
        n_matches_after_delete = 0;
        n_nodes = 1 << 8;
        n_lookups = 1 << 9;

        data = alloca(keysize);
        memset(data, 0, keysize);

        value = alloca(keysize + 1);
        memset(value, 0, keysize + 1);

        key = alloca(sizeof(*key) + keysize);
        memset(key, 0, sizeof(*key) + keysize);

        map = bpf_map_create(BPF_MAP_TYPE_LPM_TRIE, NULL,
                             sizeof(*key) + keysize,
                             keysize + 1,
                             4096,
                             &opts);
        assert(map >= 0);

        for (i = 0; i < n_nodes; ++i) {
                for (j = 0; j < keysize; ++j)
                        value[j] = rand() & 0xff;
                value[keysize] = rand() % (8 * keysize + 1);

                list = tlpm_add(list, value, value[keysize]);

                key->prefixlen = value[keysize];
                memcpy(key->data, value, keysize);
                r = bpf_map_update_elem(map, key, value, 0);
                assert(!r);
        }

        for (i = 0; i < n_lookups; ++i) {
                for (j = 0; j < keysize; ++j)
                        data[j] = rand() & 0xff;

                t = tlpm_match(list, data, 8 * keysize);

                key->prefixlen = 8 * keysize;
                memcpy(key->data, data, keysize);
                r = bpf_map_lookup_elem(map, key, value);
                assert(!r || errno == ENOENT);
                assert(!t == !!r);

                if (t) {
                        ++n_matches;
                        assert(t->n_bits == value[keysize]);
                        for (j = 0; j < t->n_bits; ++j)
                                assert((t->key[j / 8] & (1 << (7 - j % 8))) ==
                                       (value[j / 8] & (1 << (7 - j % 8))));
                }
        }

        /* Remove the first half of the elements in the tlpm and the
         * corresponding nodes from the bpf-lpm.  Then run the same
         * large number of random lookups in both and make sure they match.
         * Note: we need to count the number of nodes actually inserted
         * since there may have been duplicates.
         */
        for (i = 0, t = list; t; i++, t = t->next)
                ;
        for (j = 0; j < i / 2; ++j) {
                key->prefixlen = list->n_bits;
                memcpy(key->data, list->key, keysize);
                r = bpf_map_delete_elem(map, key);
                assert(!r);
                list = tlpm_delete(list, list->key, list->n_bits);
                assert(list);
        }
        for (i = 0; i < n_lookups; ++i) {
                for (j = 0; j < keysize; ++j)
                        data[j] = rand() & 0xff;

                t = tlpm_match(list, data, 8 * keysize);

                key->prefixlen = 8 * keysize;
                memcpy(key->data, data, keysize);
                r = bpf_map_lookup_elem(map, key, value);
                assert(!r || errno == ENOENT);
                assert(!t == !!r);

                if (t) {
                        ++n_matches_after_delete;
                        assert(t->n_bits == value[keysize]);
                        for (j = 0; j < t->n_bits; ++j)
                                assert((t->key[j / 8] & (1 << (7 - j % 8))) ==
                                       (value[j / 8] & (1 << (7 - j % 8))));
                }
        }

        close(map);
        tlpm_clear(list);

        /* With 255 random nodes in the map, we are pretty likely to match
         * something on every lookup. For statistics, use this:
         *
         *     printf("          nodes: %zu\n"
         *            "        lookups: %zu\n"
         *            "        matches: %zu\n"
         *            "matches(delete): %zu\n",
         *            n_nodes, n_lookups, n_matches, n_matches_after_delete);
         */
}

/* Test the implementation with some 'real world' examples */

static void test_lpm_ipaddr(void)
{
        LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_NO_PREALLOC);
        struct bpf_lpm_trie_key_u8 *key_ipv4;
        struct bpf_lpm_trie_key_u8 *key_ipv6;
        size_t key_size_ipv4;
        size_t key_size_ipv6;
        int map_fd_ipv4;
        int map_fd_ipv6;
        __u64 value;

        key_size_ipv4 = sizeof(*key_ipv4) + sizeof(__u32);
        key_size_ipv6 = sizeof(*key_ipv6) + sizeof(__u32) * 4;
        key_ipv4 = alloca(key_size_ipv4);
        key_ipv6 = alloca(key_size_ipv6);

        map_fd_ipv4 = bpf_map_create(BPF_MAP_TYPE_LPM_TRIE, NULL,
                                     key_size_ipv4, sizeof(value),
                                     100, &opts);
        assert(map_fd_ipv4 >= 0);

        map_fd_ipv6 = bpf_map_create(BPF_MAP_TYPE_LPM_TRIE, NULL,
                                     key_size_ipv6, sizeof(value),
                                     100, &opts);
        assert(map_fd_ipv6 >= 0);

        /* Fill data some IPv4 and IPv6 address ranges */
        value = 1;
        key_ipv4->prefixlen = 16;
        inet_pton(AF_INET, "192.168.0.0", key_ipv4->data);
        assert(bpf_map_update_elem(map_fd_ipv4, key_ipv4, &value, 0) == 0);

        value = 2;
        key_ipv4->prefixlen = 24;
        inet_pton(AF_INET, "192.168.0.0", key_ipv4->data);
        assert(bpf_map_update_elem(map_fd_ipv4, key_ipv4, &value, 0) == 0);

        value = 3;
        key_ipv4->prefixlen = 24;
        inet_pton(AF_INET, "192.168.128.0", key_ipv4->data);
        assert(bpf_map_update_elem(map_fd_ipv4, key_ipv4, &value, 0) == 0);

        value = 5;
        key_ipv4->prefixlen = 24;
        inet_pton(AF_INET, "192.168.1.0", key_ipv4->data);
        assert(bpf_map_update_elem(map_fd_ipv4, key_ipv4, &value, 0) == 0);

        value = 4;
        key_ipv4->prefixlen = 23;
        inet_pton(AF_INET, "192.168.0.0", key_ipv4->data);
        assert(bpf_map_update_elem(map_fd_ipv4, key_ipv4, &value, 0) == 0);

        value = 0xdeadbeef;
        key_ipv6->prefixlen = 64;
        inet_pton(AF_INET6, "2a00:1450:4001:814::200e", key_ipv6->data);
        assert(bpf_map_update_elem(map_fd_ipv6, key_ipv6, &value, 0) == 0);

        /* Set tprefixlen to maximum for lookups */
        key_ipv4->prefixlen = 32;
        key_ipv6->prefixlen = 128;

        /* Test some lookups that should come back with a value */
        inet_pton(AF_INET, "192.168.128.23", key_ipv4->data);
        assert(bpf_map_lookup_elem(map_fd_ipv4, key_ipv4, &value) == 0);
        assert(value == 3);

        inet_pton(AF_INET, "192.168.0.1", key_ipv4->data);
        assert(bpf_map_lookup_elem(map_fd_ipv4, key_ipv4, &value) == 0);
        assert(value == 2);

        inet_pton(AF_INET6, "2a00:1450:4001:814::", key_ipv6->data);
        assert(bpf_map_lookup_elem(map_fd_ipv6, key_ipv6, &value) == 0);
        assert(value == 0xdeadbeef);

        inet_pton(AF_INET6, "2a00:1450:4001:814::1", key_ipv6->data);
        assert(bpf_map_lookup_elem(map_fd_ipv6, key_ipv6, &value) == 0);
        assert(value == 0xdeadbeef);

        /* Test some lookups that should not match any entry */
        inet_pton(AF_INET, "10.0.0.1", key_ipv4->data);
        assert(bpf_map_lookup_elem(map_fd_ipv4, key_ipv4, &value) == -ENOENT);

        inet_pton(AF_INET, "11.11.11.11", key_ipv4->data);
        assert(bpf_map_lookup_elem(map_fd_ipv4, key_ipv4, &value) == -ENOENT);

        inet_pton(AF_INET6, "2a00:ffff::", key_ipv6->data);
        assert(bpf_map_lookup_elem(map_fd_ipv6, key_ipv6, &value) == -ENOENT);

        close(map_fd_ipv4);
        close(map_fd_ipv6);
}

static void test_lpm_delete(void)
{
        LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_NO_PREALLOC);
        struct bpf_lpm_trie_key_u8 *key;
        size_t key_size;
        int map_fd;
        __u64 value;

        key_size = sizeof(*key) + sizeof(__u32);
        key = alloca(key_size);

        map_fd = bpf_map_create(BPF_MAP_TYPE_LPM_TRIE, NULL,
                                key_size, sizeof(value),
                                100, &opts);
        assert(map_fd >= 0);

        /* Add nodes:
         * 192.168.0.0/16   (1)
         * 192.168.0.0/24   (2)
         * 192.168.128.0/24 (3)
         * 192.168.1.0/24   (4)
         *
         *         (1)
         *        /   \
         *     (IM)    (3)
         *    /   \
         *   (2)  (4)
         */
        value = 1;
        key->prefixlen = 16;
        inet_pton(AF_INET, "192.168.0.0", key->data);
        assert(bpf_map_update_elem(map_fd, key, &value, 0) == 0);

        value = 2;
        key->prefixlen = 24;
        inet_pton(AF_INET, "192.168.0.0", key->data);
        assert(bpf_map_update_elem(map_fd, key, &value, 0) == 0);

        value = 3;
        key->prefixlen = 24;
        inet_pton(AF_INET, "192.168.128.0", key->data);
        assert(bpf_map_update_elem(map_fd, key, &value, 0) == 0);

        value = 4;
        key->prefixlen = 24;
        inet_pton(AF_INET, "192.168.1.0", key->data);
        assert(bpf_map_update_elem(map_fd, key, &value, 0) == 0);

        /* remove non-existent node */
        key->prefixlen = 32;
        inet_pton(AF_INET, "10.0.0.1", key->data);
        assert(bpf_map_lookup_elem(map_fd, key, &value) == -ENOENT);

        key->prefixlen = 30; // unused prefix so far
        inet_pton(AF_INET, "192.255.0.0", key->data);
        assert(bpf_map_delete_elem(map_fd, key) == -ENOENT);

        key->prefixlen = 16; // same prefix as the root node
        inet_pton(AF_INET, "192.255.0.0", key->data);
        assert(bpf_map_delete_elem(map_fd, key) == -ENOENT);

        /* assert initial lookup */
        key->prefixlen = 32;
        inet_pton(AF_INET, "192.168.0.1", key->data);
        assert(bpf_map_lookup_elem(map_fd, key, &value) == 0);
        assert(value == 2);

        /* remove leaf node */
        key->prefixlen = 24;
        inet_pton(AF_INET, "192.168.0.0", key->data);
        assert(bpf_map_delete_elem(map_fd, key) == 0);

        key->prefixlen = 32;
        inet_pton(AF_INET, "192.168.0.1", key->data);
        assert(bpf_map_lookup_elem(map_fd, key, &value) == 0);
        assert(value == 1);

        /* remove leaf (and intermediary) node */
        key->prefixlen = 24;
        inet_pton(AF_INET, "192.168.1.0", key->data);
        assert(bpf_map_delete_elem(map_fd, key) == 0);

        key->prefixlen = 32;
        inet_pton(AF_INET, "192.168.1.1", key->data);
        assert(bpf_map_lookup_elem(map_fd, key, &value) == 0);
        assert(value == 1);

        /* remove root node */
        key->prefixlen = 16;
        inet_pton(AF_INET, "192.168.0.0", key->data);
        assert(bpf_map_delete_elem(map_fd, key) == 0);

        key->prefixlen = 32;
        inet_pton(AF_INET, "192.168.128.1", key->data);
        assert(bpf_map_lookup_elem(map_fd, key, &value) == 0);
        assert(value == 3);

        /* remove last node */
        key->prefixlen = 24;
        inet_pton(AF_INET, "192.168.128.0", key->data);
        assert(bpf_map_delete_elem(map_fd, key) == 0);

        key->prefixlen = 32;
        inet_pton(AF_INET, "192.168.128.1", key->data);
        assert(bpf_map_lookup_elem(map_fd, key, &value) == -ENOENT);

        close(map_fd);
}

static void test_lpm_get_next_key(void)
{
        LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_NO_PREALLOC);
        struct bpf_lpm_trie_key_u8 *key_p, *next_key_p;
        size_t key_size;
        __u32 value = 0;
        int map_fd;

        key_size = sizeof(*key_p) + sizeof(__u32);
        key_p = alloca(key_size);
        next_key_p = alloca(key_size);

        map_fd = bpf_map_create(BPF_MAP_TYPE_LPM_TRIE, NULL, key_size, sizeof(value), 100, &opts);
        assert(map_fd >= 0);

        /* empty tree. get_next_key should return ENOENT */
        assert(bpf_map_get_next_key(map_fd, NULL, key_p) == -ENOENT);

        /* get and verify the first key, get the second one should fail. */
        key_p->prefixlen = 16;
        inet_pton(AF_INET, "192.168.0.0", key_p->data);
        assert(bpf_map_update_elem(map_fd, key_p, &value, 0) == 0);

        memset(key_p, 0, key_size);
        assert(bpf_map_get_next_key(map_fd, NULL, key_p) == 0);
        assert(key_p->prefixlen == 16 && key_p->data[0] == 192 &&
               key_p->data[1] == 168);

        assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == -ENOENT);

        /* no exact matching key should get the first one in post order. */
        key_p->prefixlen = 8;
        assert(bpf_map_get_next_key(map_fd, NULL, key_p) == 0);
        assert(key_p->prefixlen == 16 && key_p->data[0] == 192 &&
               key_p->data[1] == 168);

        /* add one more element (total two) */
        key_p->prefixlen = 24;
        inet_pton(AF_INET, "192.168.128.0", key_p->data);
        assert(bpf_map_update_elem(map_fd, key_p, &value, 0) == 0);

        memset(key_p, 0, key_size);
        assert(bpf_map_get_next_key(map_fd, NULL, key_p) == 0);
        assert(key_p->prefixlen == 24 && key_p->data[0] == 192 &&
               key_p->data[1] == 168 && key_p->data[2] == 128);

        memset(next_key_p, 0, key_size);
        assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
        assert(next_key_p->prefixlen == 16 && next_key_p->data[0] == 192 &&
               next_key_p->data[1] == 168);

        memcpy(key_p, next_key_p, key_size);
        assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == -ENOENT);

        /* Add one more element (total three) */
        key_p->prefixlen = 24;
        inet_pton(AF_INET, "192.168.0.0", key_p->data);
        assert(bpf_map_update_elem(map_fd, key_p, &value, 0) == 0);

        memset(key_p, 0, key_size);
        assert(bpf_map_get_next_key(map_fd, NULL, key_p) == 0);
        assert(key_p->prefixlen == 24 && key_p->data[0] == 192 &&
               key_p->data[1] == 168 && key_p->data[2] == 0);

        memset(next_key_p, 0, key_size);
        assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
        assert(next_key_p->prefixlen == 24 && next_key_p->data[0] == 192 &&
               next_key_p->data[1] == 168 && next_key_p->data[2] == 128);

        memcpy(key_p, next_key_p, key_size);
        assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
        assert(next_key_p->prefixlen == 16 && next_key_p->data[0] == 192 &&
               next_key_p->data[1] == 168);

        memcpy(key_p, next_key_p, key_size);
        assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == -ENOENT);

        /* Add one more element (total four) */
        key_p->prefixlen = 24;
        inet_pton(AF_INET, "192.168.1.0", key_p->data);
        assert(bpf_map_update_elem(map_fd, key_p, &value, 0) == 0);

        memset(key_p, 0, key_size);
        assert(bpf_map_get_next_key(map_fd, NULL, key_p) == 0);
        assert(key_p->prefixlen == 24 && key_p->data[0] == 192 &&
               key_p->data[1] == 168 && key_p->data[2] == 0);

        memset(next_key_p, 0, key_size);
        assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
        assert(next_key_p->prefixlen == 24 && next_key_p->data[0] == 192 &&
               next_key_p->data[1] == 168 && next_key_p->data[2] == 1);

        memcpy(key_p, next_key_p, key_size);
        assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
        assert(next_key_p->prefixlen == 24 && next_key_p->data[0] == 192 &&
               next_key_p->data[1] == 168 && next_key_p->data[2] == 128);

        memcpy(key_p, next_key_p, key_size);
        assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
        assert(next_key_p->prefixlen == 16 && next_key_p->data[0] == 192 &&
               next_key_p->data[1] == 168);

        memcpy(key_p, next_key_p, key_size);
        assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == -ENOENT);

        /* Add one more element (total five) */
        key_p->prefixlen = 28;
        inet_pton(AF_INET, "192.168.1.128", key_p->data);
        assert(bpf_map_update_elem(map_fd, key_p, &value, 0) == 0);

        memset(key_p, 0, key_size);
        assert(bpf_map_get_next_key(map_fd, NULL, key_p) == 0);
        assert(key_p->prefixlen == 24 && key_p->data[0] == 192 &&
               key_p->data[1] == 168 && key_p->data[2] == 0);

        memset(next_key_p, 0, key_size);
        assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
        assert(next_key_p->prefixlen == 28 && next_key_p->data[0] == 192 &&
               next_key_p->data[1] == 168 && next_key_p->data[2] == 1 &&
               next_key_p->data[3] == 128);

        memcpy(key_p, next_key_p, key_size);
        assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
        assert(next_key_p->prefixlen == 24 && next_key_p->data[0] == 192 &&
               next_key_p->data[1] == 168 && next_key_p->data[2] == 1);

        memcpy(key_p, next_key_p, key_size);
        assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
        assert(next_key_p->prefixlen == 24 && next_key_p->data[0] == 192 &&
               next_key_p->data[1] == 168 && next_key_p->data[2] == 128);

        memcpy(key_p, next_key_p, key_size);
        assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
        assert(next_key_p->prefixlen == 16 && next_key_p->data[0] == 192 &&
               next_key_p->data[1] == 168);

        memcpy(key_p, next_key_p, key_size);
        assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == -ENOENT);

        /* no exact matching key should return the first one in post order */
        key_p->prefixlen = 22;
        inet_pton(AF_INET, "192.168.1.0", key_p->data);
        assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
        assert(next_key_p->prefixlen == 24 && next_key_p->data[0] == 192 &&
               next_key_p->data[1] == 168 && next_key_p->data[2] == 0);

        close(map_fd);
}

#define MAX_TEST_KEYS   4
struct lpm_mt_test_info {
        int cmd; /* 0: update, 1: delete, 2: lookup, 3: get_next_key */
        int iter;
        int map_fd;
        struct {
                __u32 prefixlen;
                __u32 data;
        } key[MAX_TEST_KEYS];
};

static void *lpm_test_command(void *arg)
{
        int i, j, ret, iter, key_size;
        struct lpm_mt_test_info *info = arg;
        struct bpf_lpm_trie_key_u8 *key_p;

        key_size = sizeof(*key_p) + sizeof(__u32);
        key_p = alloca(key_size);
        for (iter = 0; iter < info->iter; iter++)
                for (i = 0; i < MAX_TEST_KEYS; i++) {
                        /* first half of iterations in forward order,
                         * and second half in backward order.
                         */
                        j = (iter < (info->iter / 2)) ? i : MAX_TEST_KEYS - i - 1;
                        key_p->prefixlen = info->key[j].prefixlen;
                        memcpy(key_p->data, &info->key[j].data, sizeof(__u32));
                        if (info->cmd == 0) {
                                __u32 value = j;
                                /* update must succeed */
                                assert(bpf_map_update_elem(info->map_fd, key_p, &value, 0) == 0);
                        } else if (info->cmd == 1) {
                                ret = bpf_map_delete_elem(info->map_fd, key_p);
                                assert(ret == 0 || errno == ENOENT);
                        } else if (info->cmd == 2) {
                                __u32 value;
                                ret = bpf_map_lookup_elem(info->map_fd, key_p, &value);
                                assert(ret == 0 || errno == ENOENT);
                        } else {
                                struct bpf_lpm_trie_key_u8 *next_key_p = alloca(key_size);
                                ret = bpf_map_get_next_key(info->map_fd, key_p, next_key_p);
                                assert(ret == 0 || errno == ENOENT || errno == ENOMEM);
                        }
                }

        // Pass successful exit info back to the main thread
        pthread_exit((void *)info);
}

static void setup_lpm_mt_test_info(struct lpm_mt_test_info *info, int map_fd)
{
        info->iter = 2000;
        info->map_fd = map_fd;
        info->key[0].prefixlen = 16;
        inet_pton(AF_INET, "192.168.0.0", &info->key[0].data);
        info->key[1].prefixlen = 24;
        inet_pton(AF_INET, "192.168.0.0", &info->key[1].data);
        info->key[2].prefixlen = 24;
        inet_pton(AF_INET, "192.168.128.0", &info->key[2].data);
        info->key[3].prefixlen = 24;
        inet_pton(AF_INET, "192.168.1.0", &info->key[3].data);
}

static void test_lpm_multi_thread(void)
{
        LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_NO_PREALLOC);
        struct lpm_mt_test_info info[4];
        size_t key_size, value_size;
        pthread_t thread_id[4];
        int i, map_fd;
        void *ret;

        /* create a trie */
        value_size = sizeof(__u32);
        key_size = sizeof(struct bpf_lpm_trie_key_hdr) + value_size;
        map_fd = bpf_map_create(BPF_MAP_TYPE_LPM_TRIE, NULL, key_size, value_size, 100, &opts);

        /* create 4 threads to test update, delete, lookup and get_next_key */
        setup_lpm_mt_test_info(&info[0], map_fd);
        for (i = 0; i < 4; i++) {
                if (i != 0)
                        memcpy(&info[i], &info[0], sizeof(info[i]));
                info[i].cmd = i;
                assert(pthread_create(&thread_id[i], NULL, &lpm_test_command, &info[i]) == 0);
        }

        for (i = 0; i < 4; i++)
                assert(pthread_join(thread_id[i], &ret) == 0 && ret == (void *)&info[i]);

        close(map_fd);
}

static int lpm_trie_create(unsigned int key_size, unsigned int value_size, unsigned int max_entries)
{
        LIBBPF_OPTS(bpf_map_create_opts, opts);
        int fd;

        opts.map_flags = BPF_F_NO_PREALLOC;
        fd = bpf_map_create(BPF_MAP_TYPE_LPM_TRIE, "lpm_trie", key_size, value_size, max_entries,
                            &opts);
        CHECK(fd < 0, "bpf_map_create", "error %d\n", errno);

        return fd;
}

static void test_lpm_trie_update_flags(void)
{
        struct lpm_trie_int_key key;
        unsigned int value, got;
        int fd, err;

        fd = lpm_trie_create(sizeof(key), sizeof(value), 3);

        /* invalid flags (Error) */
        key.prefixlen = 32;
        key.data = 0;
        value = 0;
        err = bpf_map_update_elem(fd, &key, &value, BPF_F_LOCK);
        CHECK(err != -EINVAL, "invalid update flag", "error %d\n", err);

        /* invalid flags (Error) */
        key.prefixlen = 32;
        key.data = 0;
        value = 0;
        err = bpf_map_update_elem(fd, &key, &value, BPF_NOEXIST | BPF_EXIST);
        CHECK(err != -EINVAL, "invalid update flag", "error %d\n", err);

        /* overwrite an empty qp-trie (Error) */
        key.prefixlen = 32;
        key.data = 0;
        value = 2;
        err = bpf_map_update_elem(fd, &key, &value, BPF_EXIST);
        CHECK(err != -ENOENT, "overwrite empty qp-trie", "error %d\n", err);

        /* add a new node */
        key.prefixlen = 16;
        key.data = 0;
        value = 1;
        err = bpf_map_update_elem(fd, &key, &value, BPF_NOEXIST);
        CHECK(err, "add new elem", "error %d\n", err);
        got = 0;
        err = bpf_map_lookup_elem(fd, &key, &got);
        CHECK(err, "lookup elem", "error %d\n", err);
        CHECK(got != value, "check value", "got %d exp %d\n", got, value);

        /* add the same node as new node (Error) */
        err = bpf_map_update_elem(fd, &key, &value, BPF_NOEXIST);
        CHECK(err != -EEXIST, "add new elem again", "error %d\n", err);

        /* overwrite the existed node */
        value = 4;
        err = bpf_map_update_elem(fd, &key, &value, BPF_EXIST);
        CHECK(err, "overwrite elem", "error %d\n", err);
        got = 0;
        err = bpf_map_lookup_elem(fd, &key, &got);
        CHECK(err, "lookup elem", "error %d\n", err);
        CHECK(got != value, "check value", "got %d exp %d\n", got, value);

        /* overwrite the node */
        value = 1;
        err = bpf_map_update_elem(fd, &key, &value, BPF_ANY);
        CHECK(err, "update elem", "error %d\n", err);
        got = 0;
        err = bpf_map_lookup_elem(fd, &key, &got);
        CHECK(err, "lookup elem", "error %d\n", err);
        CHECK(got != value, "check value", "got %d exp %d\n", got, value);

        /* overwrite a non-existent node which is the prefix of the first
         * node (Error).
         */
        key.prefixlen = 8;
        key.data = 0;
        value = 2;
        err = bpf_map_update_elem(fd, &key, &value, BPF_EXIST);
        CHECK(err != -ENOENT, "overwrite nonexistent elem", "error %d\n", err);

        /* add a new node which is the prefix of the first node */
        err = bpf_map_update_elem(fd, &key, &value, BPF_NOEXIST);
        CHECK(err, "add new elem", "error %d\n", err);
        got = 0;
        err = bpf_map_lookup_elem(fd, &key, &got);
        CHECK(err, "lookup key", "error %d\n", err);
        CHECK(got != value, "check value", "got %d exp %d\n", got, value);

        /* add another new node which will be the sibling of the first node */
        key.prefixlen = 9;
        key.data = htobe32(1 << 23);
        value = 5;
        err = bpf_map_update_elem(fd, &key, &value, BPF_NOEXIST);
        CHECK(err, "add new elem", "error %d\n", err);
        got = 0;
        err = bpf_map_lookup_elem(fd, &key, &got);
        CHECK(err, "lookup key", "error %d\n", err);
        CHECK(got != value, "check value", "got %d exp %d\n", got, value);

        /* overwrite the third node */
        value = 3;
        err = bpf_map_update_elem(fd, &key, &value, BPF_ANY);
        CHECK(err, "overwrite elem", "error %d\n", err);
        got = 0;
        err = bpf_map_lookup_elem(fd, &key, &got);
        CHECK(err, "lookup key", "error %d\n", err);
        CHECK(got != value, "check value", "got %d exp %d\n", got, value);

        /* delete the second node to make it an intermediate node */
        key.prefixlen = 8;
        key.data = 0;
        err = bpf_map_delete_elem(fd, &key);
        CHECK(err, "del elem", "error %d\n", err);

        /* overwrite the intermediate node (Error) */
        value = 2;
        err = bpf_map_update_elem(fd, &key, &value, BPF_EXIST);
        CHECK(err != -ENOENT, "overwrite nonexistent elem", "error %d\n", err);

        close(fd);
}

static void test_lpm_trie_update_full_map(void)
{
        struct lpm_trie_int_key key;
        int value, got;
        int fd, err;

        fd = lpm_trie_create(sizeof(key), sizeof(value), 3);

        /* add a new node */
        key.prefixlen = 16;
        key.data = 0;
        value = 0;
        err = bpf_map_update_elem(fd, &key, &value, BPF_NOEXIST);
        CHECK(err, "add new elem", "error %d\n", err);
        got = 0;
        err = bpf_map_lookup_elem(fd, &key, &got);
        CHECK(err, "lookup elem", "error %d\n", err);
        CHECK(got != value, "check value", "got %d exp %d\n", got, value);

        /* add new node */
        key.prefixlen = 8;
        key.data = 0;
        value = 1;
        err = bpf_map_update_elem(fd, &key, &value, BPF_NOEXIST);
        CHECK(err, "add new elem", "error %d\n", err);
        got = 0;
        err = bpf_map_lookup_elem(fd, &key, &got);
        CHECK(err, "lookup elem", "error %d\n", err);
        CHECK(got != value, "check value", "got %d exp %d\n", got, value);

        /* add new node */
        key.prefixlen = 9;
        key.data = htobe32(1 << 23);
        value = 2;
        err = bpf_map_update_elem(fd, &key, &value, BPF_NOEXIST);
        CHECK(err, "add new elem", "error %d\n", err);
        got = 0;
        err = bpf_map_lookup_elem(fd, &key, &got);
        CHECK(err, "lookup elem", "error %d\n", err);
        CHECK(got != value, "check value", "got %d exp %d\n", got, value);

        /* try to add more node (Error) */
        key.prefixlen = 32;
        key.data = 0;
        value = 3;
        err = bpf_map_update_elem(fd, &key, &value, BPF_ANY);
        CHECK(err != -ENOSPC, "add to full trie", "error %d\n", err);

        /* update the value of an existed node with BPF_EXIST */
        key.prefixlen = 16;
        key.data = 0;
        value = 4;
        err = bpf_map_update_elem(fd, &key, &value, BPF_EXIST);
        CHECK(err, "overwrite elem", "error %d\n", err);
        got = 0;
        err = bpf_map_lookup_elem(fd, &key, &got);
        CHECK(err, "lookup elem", "error %d\n", err);
        CHECK(got != value, "check value", "got %d exp %d\n", got, value);

        /* update the value of an existed node with BPF_ANY */
        key.prefixlen = 9;
        key.data = htobe32(1 << 23);
        value = 5;
        err = bpf_map_update_elem(fd, &key, &value, BPF_ANY);
        CHECK(err, "overwrite elem", "error %d\n", err);
        got = 0;
        err = bpf_map_lookup_elem(fd, &key, &got);
        CHECK(err, "lookup elem", "error %d\n", err);
        CHECK(got != value, "check value", "got %d exp %d\n", got, value);

        close(fd);
}

static int cmp_str(const void *a, const void *b)
{
        const char *str_a = *(const char **)a, *str_b = *(const char **)b;

        return strcmp(str_a, str_b);
}

/* Save strings in LPM trie. The trailing '\0' for each string will be
 * accounted in the prefixlen. The strings returned during the iteration
 * should be sorted as expected.
 */
static void test_lpm_trie_iterate_strs(void)
{
        static const char * const keys[] = {
                "ab", "abO", "abc", "abo", "abS", "abcd",
        };
        const char *sorted_keys[ARRAY_SIZE(keys)];
        struct lpm_trie_bytes_key key, next_key;
        unsigned int value, got, i, j, len;
        struct lpm_trie_bytes_key *cur;
        int fd, err;

        fd = lpm_trie_create(sizeof(key), sizeof(value), ARRAY_SIZE(keys));

        for (i = 0; i < ARRAY_SIZE(keys); i++) {
                unsigned int flags;

                /* add i-th element */
                flags = i % 2 ? BPF_NOEXIST : 0;
                len = strlen(keys[i]);
                /* include the trailing '\0' */
                key.prefixlen = (len + 1) * 8;
                memset(key.data, 0, sizeof(key.data));
                memcpy(key.data, keys[i], len);
                value = i + 100;
                err = bpf_map_update_elem(fd, &key, &value, flags);
                CHECK(err, "add elem", "#%u error %d\n", i, err);

                err = bpf_map_lookup_elem(fd, &key, &got);
                CHECK(err, "lookup elem", "#%u error %d\n", i, err);
                CHECK(got != value, "lookup elem", "#%u expect %u got %u\n", i, value, got);

                /* re-add i-th element (Error) */
                err = bpf_map_update_elem(fd, &key, &value, BPF_NOEXIST);
                CHECK(err != -EEXIST, "re-add elem", "#%u error %d\n", i, err);

                /* Overwrite i-th element */
                flags = i % 2 ? 0 : BPF_EXIST;
                value = i;
                err = bpf_map_update_elem(fd, &key, &value, flags);
                CHECK(err, "update elem", "error %d\n", err);

                /* Lookup #[0~i] elements */
                for (j = 0; j <= i; j++) {
                        len = strlen(keys[j]);
                        key.prefixlen = (len + 1) * 8;
                        memset(key.data, 0, sizeof(key.data));
                        memcpy(key.data, keys[j], len);
                        err = bpf_map_lookup_elem(fd, &key, &got);
                        CHECK(err, "lookup elem", "#%u/%u error %d\n", i, j, err);
                        CHECK(got != j, "lookup elem", "#%u/%u expect %u got %u\n",
                              i, j, value, got);
                }
        }

        /* Add element to a full qp-trie (Error) */
        key.prefixlen = sizeof(key.data) * 8;
        memset(key.data, 0, sizeof(key.data));
        value = 0;
        err = bpf_map_update_elem(fd, &key, &value, 0);
        CHECK(err != -ENOSPC, "add to full qp-trie", "error %d\n", err);

        /* Iterate sorted elements: no deletion */
        memcpy(sorted_keys, keys, sizeof(keys));
        qsort(sorted_keys, ARRAY_SIZE(sorted_keys), sizeof(sorted_keys[0]), cmp_str);
        cur = NULL;
        for (i = 0; i < ARRAY_SIZE(sorted_keys); i++) {
                len = strlen(sorted_keys[i]);
                err = bpf_map_get_next_key(fd, cur, &next_key);
                CHECK(err, "iterate", "#%u error %d\n", i, err);
                CHECK(next_key.prefixlen != (len + 1) * 8, "iterate",
                      "#%u invalid len %u expect %u\n",
                      i, next_key.prefixlen, (len + 1) * 8);
                CHECK(memcmp(sorted_keys[i], next_key.data, len + 1), "iterate",
                      "#%u got %.*s exp %.*s\n", i, len, next_key.data, len, sorted_keys[i]);

                cur = &next_key;
        }
        err = bpf_map_get_next_key(fd, cur, &next_key);
        CHECK(err != -ENOENT, "more element", "error %d\n", err);

        /* Iterate sorted elements: delete the found key after each iteration */
        cur = NULL;
        for (i = 0; i < ARRAY_SIZE(sorted_keys); i++) {
                len = strlen(sorted_keys[i]);
                err = bpf_map_get_next_key(fd, cur, &next_key);
                CHECK(err, "iterate", "#%u error %d\n", i, err);
                CHECK(next_key.prefixlen != (len + 1) * 8, "iterate",
                      "#%u invalid len %u expect %u\n",
                      i, next_key.prefixlen, (len + 1) * 8);
                CHECK(memcmp(sorted_keys[i], next_key.data, len + 1), "iterate",
                      "#%u got %.*s exp %.*s\n", i, len, next_key.data, len, sorted_keys[i]);

                cur = &next_key;

                err = bpf_map_delete_elem(fd, cur);
                CHECK(err, "delete", "#%u error %d\n", i, err);
        }
        err = bpf_map_get_next_key(fd, cur, &next_key);
        CHECK(err != -ENOENT, "non-empty qp-trie", "error %d\n", err);

        close(fd);
}

/* Use the fixed prefixlen (32) and save integers in LPM trie. The iteration of
 * LPM trie will return these integers in big-endian order, therefore, convert
 * these integers to big-endian before update. After each iteration, delete the
 * found key (the smallest integer) and expect the next iteration will return
 * the second smallest number.
 */
static void test_lpm_trie_iterate_ints(void)
{
        struct lpm_trie_int_key key, next_key;
        unsigned int i, max_entries;
        struct lpm_trie_int_key *cur;
        unsigned int *data_set;
        int fd, err;
        bool value;

        max_entries = 4096;
        data_set = calloc(max_entries, sizeof(*data_set));
        CHECK(!data_set, "malloc", "no mem\n");
        for (i = 0; i < max_entries; i++)
                data_set[i] = i;

        fd = lpm_trie_create(sizeof(key), sizeof(value), max_entries);
        value = true;
        for (i = 0; i < max_entries; i++) {
                key.prefixlen = 32;
                key.data = htobe32(data_set[i]);

                err = bpf_map_update_elem(fd, &key, &value, BPF_NOEXIST);
                CHECK(err, "add elem", "#%u error %d\n", i, err);
        }

        cur = NULL;
        for (i = 0; i < max_entries; i++) {
                err = bpf_map_get_next_key(fd, cur, &next_key);
                CHECK(err, "iterate", "#%u error %d\n", i, err);
                CHECK(next_key.prefixlen != 32, "iterate", "#%u invalid len %u\n",
                      i, next_key.prefixlen);
                CHECK(be32toh(next_key.data) != data_set[i], "iterate", "#%u got 0x%x exp 0x%x\n",
                      i, be32toh(next_key.data), data_set[i]);
                cur = &next_key;

                /*
                 * Delete the minimal key, the next call of bpf_get_next_key()
                 * will return the second minimal key.
                 */
                err = bpf_map_delete_elem(fd, &next_key);
                CHECK(err, "del elem", "#%u elem error %d\n", i, err);
        }
        err = bpf_map_get_next_key(fd, cur, &next_key);
        CHECK(err != -ENOENT, "more element", "error %d\n", err);

        err = bpf_map_get_next_key(fd, NULL, &next_key);
        CHECK(err != -ENOENT, "no-empty qp-trie", "error %d\n", err);

        free(data_set);

        close(fd);
}

void test_lpm_trie_map_basic_ops(void)
{
        int i;

        /* we want predictable, pseudo random tests */
        srand(0xf00ba1);

        test_lpm_basic();
        test_lpm_order();

        /* Test with 8, 16, 24, 32, ... 128 bit prefix length */
        for (i = 1; i <= 16; ++i)
                test_lpm_map(i);

        test_lpm_ipaddr();
        test_lpm_delete();
        test_lpm_get_next_key();
        test_lpm_multi_thread();

        test_lpm_trie_update_flags();
        test_lpm_trie_update_full_map();
        test_lpm_trie_iterate_strs();
        test_lpm_trie_iterate_ints();

        printf("%s: PASS\n", __func__);
}