From 4d3381f5a322dd5db2477e224821790478488173 Mon Sep 17 00:00:00 2001 From: David Herrmann Date: Sat, 21 Jan 2017 17:26:12 +0100 Subject: [PATCH] bpf: Add tests for the lpm trie map The first part of this program runs randomized tests against the lpm-bpf-map. It implements a "Trivial Longest Prefix Match" (tlpm) based on simple, linear, single 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. The second part uses 'real world' IPv4 and IPv6 addresses and tests the trie with those. Signed-off-by: David Herrmann Signed-off-by: Daniel Mack Acked-by: Alexei Starovoitov Signed-off-by: David S. Miller --- tools/testing/selftests/bpf/.gitignore | 1 + tools/testing/selftests/bpf/Makefile | 4 +- tools/testing/selftests/bpf/test_lpm_map.c | 358 +++++++++++++++++++++ 3 files changed, 361 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/bpf/test_lpm_map.c 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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; +} -- 2.20.1