3 files changed, 361 insertions, 2 deletions

diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore
index 071431bedde8..d3b1c9bca407 100644
--- a/tools/testing/selftests/bpf/.gitignore
+++ b/tools/testing/selftests/bpf/.gitignore
@@ -1,3 +1,4 @@
 test_verifier
 test_maps
 test_lru_map
+test_lpm_map
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 7a5f24543a5f..064a3e5f2836 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -1,8 +1,8 @@
 CFLAGS += -Wall -O2 -I../../../../usr/include
 
-test_objs = test_verifier test_maps test_lru_map
+test_objs = test_verifier test_maps test_lru_map test_lpm_map
 
-TEST_PROGS := test_verifier test_maps test_lru_map test_kmod.sh
+TEST_PROGS := test_verifier test_maps test_lru_map test_lpm_map test_kmod.sh
 TEST_FILES := $(test_objs)
 
 all: $(test_objs)
diff --git a/tools/testing/selftests/bpf/test_lpm_map.c b/tools/testing/selftests/bpf/test_lpm_map.c
new file mode 100644
index 000000000000..26775c00273f
--- /dev/null
+++ b/tools/testing/selftests/bpf/test_lpm_map.c
@@ -0,0 +1,358 @@
+/*
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+
+#include "bpf_sys.h"
+#include "bpf_util.h"
+
+struct tlpm_node {
+        struct tlpm_node *next;
+        size_t n_bits;
+        uint8_t key[];
+};
+
+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;
+
+        /* add new entry with @key/@n_bits to @list and return new head */
+
+        n = (n_bits + 7) / 8;
+        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 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));
+
+        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)
+{
+        size_t i, j, n_matches, n_nodes, n_lookups;
+        struct tlpm_node *t, *list = NULL;
+        struct bpf_lpm_trie_key *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_nodes = 1 << 8;
+        n_lookups = 1 << 16;
+
+        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,
+                             sizeof(*key) + keysize,
+                             keysize + 1,
+                             4096,
+                             BPF_F_NO_PREALLOC);
+        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(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(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))));
+                }
+        }
+
+        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", n_nodes, n_lookups, n_matches);
+         */
+}
+
+/* Test the implementation with some 'real world' examples */
+
+static void test_lpm_ipaddr(void)
+{
+        struct bpf_lpm_trie_key *key_ipv4;
+        struct bpf_lpm_trie_key *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,
+                                     key_size_ipv4, sizeof(value),
+                                     100, BPF_F_NO_PREALLOC);
+        assert(map_fd_ipv4 >= 0);
+
+        map_fd_ipv6 = bpf_map_create(BPF_MAP_TYPE_LPM_TRIE,
+                                     key_size_ipv6, sizeof(value),
+                                     100, BPF_F_NO_PREALLOC);
+        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(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(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(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(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(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(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(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(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(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(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(map_fd_ipv4, key_ipv4, &value) == -1 &&
+               errno == ENOENT);
+
+        inet_pton(AF_INET, "11.11.11.11", key_ipv4->data);
+        assert(bpf_map_lookup(map_fd_ipv4, key_ipv4, &value) == -1 &&
+               errno == ENOENT);
+
+        inet_pton(AF_INET6, "2a00:ffff::", key_ipv6->data);
+        assert(bpf_map_lookup(map_fd_ipv6, key_ipv6, &value) == -1 &&
+               errno == ENOENT);
+
+        close(map_fd_ipv4);
+        close(map_fd_ipv6);
+}
+
+int main(void)
+{
+        struct rlimit limit  = { RLIM_INFINITY, RLIM_INFINITY };
+        int i, ret;
+
+        /* we want predictable, pseudo random tests */
+        srand(0xf00ba1);
+
+        /* allow unlimited locked memory */
+        ret = setrlimit(RLIMIT_MEMLOCK, &limit);
+        if (ret < 0)
+                perror("Unable to lift memlock rlimit");
+
+        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();
+
+        printf("test_lpm: OK\n");
+        return 0;
+}