Merge branch 'bpf-lpm-delete' (76707127) · Commits · e / devices / android_kernel_fairphone_FP4

kernel/bpf/lpm_trie.c

+77 −3

Original line number	Diff line number	Diff line
		@@ -389,10 +389,84 @@ static int trie_update_elem(struct bpf_map *map,
		return ret;
		}

		static int trie_delete_elem(struct bpf_map map, void key)
		/* Called from syscall or from eBPF program */
		static int trie_delete_elem(struct bpf_map map, void _key)
		{
		/* TODO */
		return -ENOSYS;
		struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
		struct bpf_lpm_trie_key *key = _key;
		struct lpm_trie_node __rcu **trim;
		struct lpm_trie_node *node;
		unsigned long irq_flags;
		unsigned int next_bit;
		size_t matchlen = 0;
		int ret = 0;

		if (key->prefixlen > trie->max_prefixlen)
		return -EINVAL;

		raw_spin_lock_irqsave(&trie->lock, irq_flags);

		/* Walk the tree looking for an exact key/length match and keeping
		* track of where we could begin trimming the tree. The trim-point
		* is the sub-tree along the walk consisting of only single-child
		* intermediate nodes and ending at a leaf node that we want to
		* remove.
		*/
		trim = &trie->root;
		node = rcu_dereference_protected(
		trie->root, lockdep_is_held(&trie->lock));
		while (node) {
		matchlen = longest_prefix_match(trie, node, key);

		if (node->prefixlen != matchlen \|\|
		node->prefixlen == key->prefixlen)
		break;

		next_bit = extract_bit(key->data, node->prefixlen);
		/* If we hit a node that has more than one child or is a valid
		* prefix itself, do not remove it. Reset the root of the trim
		* path to its descendant on our path.
		*/
		if (!(node->flags & LPM_TREE_NODE_FLAG_IM) \|\|
		(node->child[0] && node->child[1]))
		trim = &node->child[next_bit];
		node = rcu_dereference_protected(
		node->child[next_bit], lockdep_is_held(&trie->lock));
		}

		if (!node \|\| node->prefixlen != key->prefixlen \|\|
		(node->flags & LPM_TREE_NODE_FLAG_IM)) {
		ret = -ENOENT;
		goto out;
		}

		trie->n_entries--;

		/* If the node we are removing is not a leaf node, simply mark it
		* as intermediate and we are done.
		*/
		if (rcu_access_pointer(node->child[0]) \|\|
		rcu_access_pointer(node->child[1])) {
		node->flags \|= LPM_TREE_NODE_FLAG_IM;
		goto out;
		}

		/* trim should now point to the slot holding the start of a path from
		* zero or more intermediate nodes to our leaf node for deletion.
		*/
		while ((node = rcu_dereference_protected(
		*trim, lockdep_is_held(&trie->lock)))) {
		RCU_INIT_POINTER(*trim, NULL);
		trim = rcu_access_pointer(node->child[0]) ?
		&node->child[0] :
		&node->child[1];
		kfree_rcu(node, rcu);
		}

		out:
		raw_spin_unlock_irqrestore(&trie->lock, irq_flags);

		return ret;
		}

		#define LPM_DATA_SIZE_MAX 256

tools/testing/selftests/bpf/test_lpm_map.c

+196 −5

Original line number	Diff line number	Diff line
		@@ -31,6 +31,10 @@ struct tlpm_node {
		uint8_t key[];
		};

		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)
		@@ -38,9 +42,17 @@ static struct tlpm_node tlpm_add(struct tlpm_node list,
		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 */

		n = (n_bits + 7) / 8;
		node = malloc(sizeof(*node) + n);
		assert(node);

		@@ -92,6 +104,34 @@ static struct tlpm_node tlpm_match(struct tlpm_node 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;
		@@ -114,6 +154,13 @@ static void test_lpm_basic(void)
		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);
		}

		@@ -158,7 +205,7 @@ static void test_lpm_order(void)

		static void test_lpm_map(int keysize)
		{
		size_t i, j, n_matches, n_nodes, n_lookups;
		size_t i, j, n_matches, n_matches_after_delete, n_nodes, n_lookups;
		struct tlpm_node t, list = NULL;
		struct bpf_lpm_trie_key *key;
		uint8_t data, value;
		@@ -170,6 +217,7 @@ static void test_lpm_map(int keysize)
		*/

		n_matches = 0;
		n_matches_after_delete = 0;
		n_nodes = 1 << 8;
		n_lookups = 1 << 16;

		@@ -223,6 +271,43 @@ static void test_lpm_map(int keysize)
		}
		}

		/* 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);

		@@ -231,7 +316,9 @@ static void test_lpm_map(int keysize)
		*
		* printf(" nodes: %zu\n"
		* " lookups: %zu\n"
		* "matches: %zu\n", n_nodes, n_lookups, n_matches);
		* " matches: %zu\n"
		* "matches(delete): %zu\n",
		* n_nodes, n_lookups, n_matches, n_matches_after_delete);
		*/
		}

		@@ -331,6 +418,108 @@ static void test_lpm_ipaddr(void)
		close(map_fd_ipv6);
		}

		static void test_lpm_delete(void)
		{
		struct bpf_lpm_trie_key *key;
		size_t key_size;
		int map_fd;
		__u64 value;

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

		map_fd = bpf_create_map(BPF_MAP_TYPE_LPM_TRIE,
		key_size, sizeof(value),
		100, BPF_F_NO_PREALLOC);
		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) == -1 &&
		errno == 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) == -1 &&
		errno == ENOENT);

		close(map_fd);
		}

		int main(void)
		{
		struct rlimit limit = { RLIM_INFINITY, RLIM_INFINITY };
		@@ -353,6 +542,8 @@ int main(void)

		test_lpm_ipaddr();

		test_lpm_delete();

		printf("test_lpm: OK\n");
		return 0;
		}