Adding upstream version 3.8.1.upstream/3.8.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 4695 insertions, 0 deletions

diff --git a/src/plugins/fuzzy_check.c b/src/plugins/fuzzy_check.c
new file mode 100644
index 0000000..85db83d
--- /dev/null
+++ b/src/plugins/fuzzy_check.c
@@ -0,0 +1,4695 @@
+/*
+ * Copyright 2023 Vsevolod Stakhov
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/***MODULE:fuzzy
+ * rspamd module that checks fuzzy checksums for messages
+ *
+ * Allowed options:
+ * - symbol (string): symbol to insert (default: 'R_FUZZY')
+ * - max_score (double): maximum score to that weights of hashes would be normalized (default: 0 - no normalization)
+ *
+ * - fuzzy_map (string): a string that contains map in format { fuzzy_key => [ symbol, weight ] } where fuzzy_key is number of
+ *   fuzzy list. This string itself should be in format 1:R_FUZZY_SAMPLE1:10,2:R_FUZZY_SAMPLE2:1 etc, where first number is fuzzy
+ *   key, second is symbol to insert and third - weight for normalization
+ *
+ * - min_length (integer): minimum length (in characters) for text part to be checked for fuzzy hash (default: 0 - no limit)
+ * - whitelist (map string): map of ip addresses that should not be checked with this module
+ * - servers (string): list of fuzzy servers in format "server1:port,server2:port" - these servers would be used for checking and storing
+ *   fuzzy hashes
+ */
+
+#include "config.h"
+#include "libmime/message.h"
+#include "libserver/maps/map.h"
+#include "libserver/maps/map_helpers.h"
+#include "libmime/images.h"
+#include "libserver/worker_util.h"
+#include "libserver/mempool_vars_internal.h"
+#include "fuzzy_wire.h"
+#include "utlist.h"
+#include "ottery.h"
+#include "lua/lua_common.h"
+#include "unix-std.h"
+#include "libserver/http/http_private.h"
+#include "libserver/http/http_router.h"
+#include "libstat/stat_api.h"
+#include <math.h>
+#include "libutil/libev_helper.h"
+
+#define DEFAULT_SYMBOL "R_FUZZY_HASH"
+
+#define DEFAULT_IO_TIMEOUT 1.0
+#define DEFAULT_RETRANSMITS 3
+#define DEFAULT_MAX_ERRORS 4
+#define DEFAULT_REVIVE_TIME 60
+#define DEFAULT_PORT 11335
+
+#define RSPAMD_FUZZY_PLUGIN_VERSION RSPAMD_FUZZY_VERSION
+
+static const gint rspamd_fuzzy_hash_len = 5;
+static const gchar *M = "fuzzy check";
+struct fuzzy_ctx;
+
+struct fuzzy_mapping {
+	guint64 fuzzy_flag;
+	const gchar *symbol;
+	double weight;
+};
+
+struct fuzzy_rule {
+	struct upstream_list *servers;
+	const gchar *symbol;
+	const gchar *algorithm_str;
+	const gchar *name;
+	const ucl_object_t *ucl_obj;
+	enum rspamd_shingle_alg alg;
+	GHashTable *mappings;
+	GPtrArray *fuzzy_headers;
+	GString *hash_key;
+	GString *shingles_key;
+	gdouble io_timeout;
+	struct rspamd_cryptobox_keypair *local_key;
+	struct rspamd_cryptobox_pubkey *peer_key;
+	double max_score;
+	double weight_threshold;
+	gboolean read_only;
+	gboolean skip_unknown;
+	gboolean no_share;
+	gboolean no_subject;
+	gint learn_condition_cb;
+	guint32 retransmits;
+	struct rspamd_hash_map_helper *skip_map;
+	struct fuzzy_ctx *ctx;
+	gint lua_id;
+};
+
+struct fuzzy_ctx {
+	struct module_ctx ctx;
+	rspamd_mempool_t *fuzzy_pool;
+	GPtrArray *fuzzy_rules;
+	struct rspamd_config *cfg;
+	const gchar *default_symbol;
+	struct rspamd_radix_map_helper *whitelist;
+	struct rspamd_keypair_cache *keypairs_cache;
+	guint max_errors;
+	gdouble revive_time;
+	gdouble io_timeout;
+	gint check_mime_part_ref; /* Lua callback */
+	gint process_rule_ref;    /* Lua callback */
+	gint cleanup_rules_ref;
+	guint32 retransmits;
+	gboolean enabled;
+};
+
+enum fuzzy_result_type {
+	FUZZY_RESULT_TXT,
+	FUZZY_RESULT_IMG,
+	FUZZY_RESULT_CONTENT,
+	FUZZY_RESULT_BIN
+};
+
+struct fuzzy_client_result {
+	const gchar *symbol;
+	gchar *option;
+	gdouble score;
+	gdouble prob;
+	enum fuzzy_result_type type;
+};
+
+struct fuzzy_client_session {
+	GPtrArray *commands;
+	GPtrArray *results;
+	struct rspamd_task *task;
+	struct rspamd_symcache_dynamic_item *item;
+	struct upstream *server;
+	struct fuzzy_rule *rule;
+	struct ev_loop *event_loop;
+	struct rspamd_io_ev ev;
+	gint state;
+	gint fd;
+	guint retransmits;
+};
+
+struct fuzzy_learn_session {
+	GPtrArray *commands;
+	gint *saved;
+	struct {
+		const gchar *error_message;
+		gint error_code;
+	} err;
+	struct rspamd_http_connection_entry *http_entry;
+	struct rspamd_async_session *session;
+	struct upstream *server;
+	struct fuzzy_rule *rule;
+	struct rspamd_task *task;
+	struct ev_loop *event_loop;
+	struct rspamd_io_ev ev;
+	gint fd;
+	guint retransmits;
+};
+
+#define FUZZY_CMD_FLAG_REPLIED (1 << 0)
+#define FUZZY_CMD_FLAG_SENT (1 << 1)
+#define FUZZY_CMD_FLAG_IMAGE (1 << 2)
+#define FUZZY_CMD_FLAG_CONTENT (1 << 3)
+
+#define FUZZY_CHECK_FLAG_NOIMAGES (1 << 0)
+#define FUZZY_CHECK_FLAG_NOATTACHMENTS (1 << 1)
+#define FUZZY_CHECK_FLAG_NOTEXT (1 << 2)
+
+struct fuzzy_cmd_io {
+	guint32 tag;
+	guint32 flags;
+	struct iovec io;
+	struct rspamd_mime_part *part;
+	struct rspamd_fuzzy_cmd cmd;
+};
+
+
+static const char *default_headers = "Subject,Content-Type,Reply-To,X-Mailer";
+
+static void fuzzy_symbol_callback(struct rspamd_task *task,
+								  struct rspamd_symcache_dynamic_item *item,
+								  void *unused);
+
+/* Initialization */
+gint fuzzy_check_module_init(struct rspamd_config *cfg,
+							 struct module_ctx **ctx);
+gint fuzzy_check_module_config(struct rspamd_config *cfg, bool valdate);
+gint fuzzy_check_module_reconfig(struct rspamd_config *cfg);
+static gint fuzzy_attach_controller(struct module_ctx *ctx,
+									GHashTable *commands);
+static gint fuzzy_lua_learn_handler(lua_State *L);
+static gint fuzzy_lua_unlearn_handler(lua_State *L);
+static gint fuzzy_lua_gen_hashes_handler(lua_State *L);
+static gint fuzzy_lua_hex_hashes_handler(lua_State *L);
+static gint fuzzy_lua_list_storages(lua_State *L);
+static gint fuzzy_lua_ping_storage(lua_State *L);
+
+module_t fuzzy_check_module = {
+	"fuzzy_check",
+	fuzzy_check_module_init,
+	fuzzy_check_module_config,
+	fuzzy_check_module_reconfig,
+	fuzzy_attach_controller,
+	RSPAMD_MODULE_VER,
+	(guint) -1,
+};
+
+static inline struct fuzzy_ctx *
+fuzzy_get_context(struct rspamd_config *cfg)
+{
+	return (struct fuzzy_ctx *) g_ptr_array_index(cfg->c_modules,
+												  fuzzy_check_module.ctx_offset);
+}
+
+static void
+parse_flags(struct fuzzy_rule *rule,
+			struct rspamd_config *cfg,
+			const ucl_object_t *val,
+			gint cb_id)
+{
+	const ucl_object_t *elt;
+	struct fuzzy_mapping *map;
+	const gchar *sym = NULL;
+
+	if (val->type == UCL_STRING) {
+		msg_err_config(
+			"string mappings are deprecated and no longer supported, use new style configuration");
+	}
+	else if (val->type == UCL_OBJECT) {
+		elt = ucl_object_lookup(val, "symbol");
+		if (elt == NULL || !ucl_object_tostring_safe(elt, &sym)) {
+			sym = ucl_object_key(val);
+		}
+		if (sym != NULL) {
+			map =
+				rspamd_mempool_alloc(cfg->cfg_pool,
+									 sizeof(struct fuzzy_mapping));
+			map->symbol = sym;
+			elt = ucl_object_lookup(val, "flag");
+
+			if (elt != NULL) {
+				map->fuzzy_flag = ucl_obj_toint(elt);
+
+				elt = ucl_object_lookup(val, "max_score");
+
+				if (elt != NULL) {
+					map->weight = ucl_obj_todouble(elt);
+				}
+				else {
+					map->weight = rule->max_score;
+				}
+				/* Add flag to hash table */
+				g_hash_table_insert(rule->mappings,
+									GINT_TO_POINTER(map->fuzzy_flag), map);
+				rspamd_symcache_add_symbol(cfg->cache,
+										   map->symbol, 0,
+										   NULL, NULL,
+										   SYMBOL_TYPE_VIRTUAL | SYMBOL_TYPE_FINE,
+										   cb_id);
+			}
+			else {
+				msg_err_config("fuzzy_map parameter has no flag definition");
+			}
+		}
+		else {
+			msg_err_config("fuzzy_map parameter has no symbol definition");
+		}
+	}
+	else {
+		msg_err_config("fuzzy_map parameter is of an unsupported type");
+	}
+}
+
+static GPtrArray *
+parse_fuzzy_headers(struct rspamd_config *cfg, const gchar *str)
+{
+	gchar **strvec;
+	gint num, i;
+	GPtrArray *res;
+
+	strvec = g_strsplit_set(str, ",", 0);
+	num = g_strv_length(strvec);
+	res = g_ptr_array_sized_new(num);
+
+	for (i = 0; i < num; i++) {
+		g_strstrip(strvec[i]);
+		g_ptr_array_add(res, rspamd_mempool_strdup(
+								 cfg->cfg_pool, strvec[i]));
+	}
+
+	g_strfreev(strvec);
+
+	return res;
+}
+
+static double
+fuzzy_normalize(gint32 in, double weight)
+{
+	if (weight == 0) {
+		return 0;
+	}
+#ifdef HAVE_TANH
+	return tanh(G_E * (double) in / weight);
+#else
+	return (in < weight ? in / weight : weight);
+#endif
+}
+
+static struct fuzzy_rule *
+fuzzy_rule_new(const char *default_symbol, rspamd_mempool_t *pool)
+{
+	struct fuzzy_rule *rule;
+
+	rule = rspamd_mempool_alloc0(pool, sizeof(struct fuzzy_rule));
+
+	rule->mappings = g_hash_table_new(g_direct_hash, g_direct_equal);
+	rule->symbol = default_symbol;
+	rspamd_mempool_add_destructor(pool,
+								  (rspamd_mempool_destruct_t) g_hash_table_unref,
+								  rule->mappings);
+	rule->read_only = FALSE;
+	rule->weight_threshold = NAN;
+
+	return rule;
+}
+
+static void
+fuzzy_free_rule(gpointer r)
+{
+	struct fuzzy_rule *rule = (struct fuzzy_rule *) r;
+
+	g_string_free(rule->hash_key, TRUE);
+	g_string_free(rule->shingles_key, TRUE);
+
+	if (rule->local_key) {
+		rspamd_keypair_unref(rule->local_key);
+	}
+
+	if (rule->peer_key) {
+		rspamd_pubkey_unref(rule->peer_key);
+	}
+}
+
+static gint
+fuzzy_parse_rule(struct rspamd_config *cfg, const ucl_object_t *obj,
+				 const gchar *name, gint cb_id)
+{
+	const ucl_object_t *value, *cur;
+	struct fuzzy_rule *rule;
+	ucl_object_iter_t it = NULL;
+	const char *k = NULL, *key_str = NULL, *shingles_key_str = NULL, *lua_script;
+	struct fuzzy_ctx *fuzzy_module_ctx = fuzzy_get_context(cfg);
+
+	if (obj->type != UCL_OBJECT) {
+		msg_err_config("invalid rule definition");
+		return -1;
+	}
+
+	if ((value = ucl_object_lookup_any(obj, "enabled", "enable", NULL)) != NULL) {
+		if (!ucl_object_toboolean(value)) {
+			msg_info_config("fuzzy rule %s is disabled by configuration", name);
+
+			return 0;
+		}
+	}
+
+	rule = fuzzy_rule_new(fuzzy_module_ctx->default_symbol,
+						  cfg->cfg_pool);
+	rule->ucl_obj = obj;
+	rule->ctx = fuzzy_module_ctx;
+	rule->learn_condition_cb = -1;
+	rule->alg = RSPAMD_SHINGLES_OLD;
+	rule->skip_map = NULL;
+
+	if ((value = ucl_object_lookup(obj, "skip_hashes")) != NULL) {
+		rspamd_map_add_from_ucl(cfg, value,
+								"Fuzzy hashes whitelist",
+								rspamd_kv_list_read,
+								rspamd_kv_list_fin,
+								rspamd_kv_list_dtor,
+								(void **) &rule->skip_map,
+								NULL, RSPAMD_MAP_DEFAULT);
+	}
+
+	if ((value = ucl_object_lookup(obj, "headers")) != NULL) {
+		it = NULL;
+		while ((cur = ucl_object_iterate(value, &it, value->type == UCL_ARRAY)) != NULL) {
+			GPtrArray *tmp;
+			guint i;
+			gpointer ptr;
+
+			tmp = parse_fuzzy_headers(cfg, ucl_obj_tostring(cur));
+
+			if (tmp) {
+				if (rule->fuzzy_headers) {
+					PTR_ARRAY_FOREACH(tmp, i, ptr)
+					{
+						g_ptr_array_add(rule->fuzzy_headers, ptr);
+					}
+
+					g_ptr_array_free(tmp, TRUE);
+				}
+				else {
+					rule->fuzzy_headers = tmp;
+				}
+			}
+		}
+	}
+	else {
+		rule->fuzzy_headers = parse_fuzzy_headers(cfg, default_headers);
+	}
+
+	if (rule->fuzzy_headers != NULL) {
+		rspamd_mempool_add_destructor(cfg->cfg_pool,
+									  (rspamd_mempool_destruct_t) rspamd_ptr_array_free_hard,
+									  rule->fuzzy_headers);
+	}
+
+
+	if ((value = ucl_object_lookup(obj, "max_score")) != NULL) {
+		rule->max_score = ucl_obj_todouble(value);
+	}
+
+	if ((value = ucl_object_lookup(obj, "retransmits")) != NULL) {
+		rule->retransmits = ucl_obj_toint(value);
+	}
+	else {
+		rule->retransmits = fuzzy_module_ctx->retransmits;
+	}
+
+	if ((value = ucl_object_lookup(obj, "timeout")) != NULL) {
+		rule->io_timeout = ucl_obj_todouble(value);
+	}
+	else {
+		rule->io_timeout = fuzzy_module_ctx->io_timeout;
+	}
+
+	if ((value = ucl_object_lookup(obj, "symbol")) != NULL) {
+		rule->symbol = ucl_obj_tostring(value);
+	}
+
+	if (name) {
+		rule->name = name;
+	}
+	else {
+		rule->name = rule->symbol;
+	}
+
+
+	if ((value = ucl_object_lookup(obj, "read_only")) != NULL) {
+		rule->read_only = ucl_obj_toboolean(value);
+	}
+
+	if ((value = ucl_object_lookup(obj, "skip_unknown")) != NULL) {
+		rule->skip_unknown = ucl_obj_toboolean(value);
+	}
+
+	if ((value = ucl_object_lookup(obj, "no_share")) != NULL) {
+		rule->no_share = ucl_obj_toboolean(value);
+	}
+
+	if ((value = ucl_object_lookup(obj, "no_subject")) != NULL) {
+		rule->no_subject = ucl_obj_toboolean(value);
+	}
+
+	if ((value = ucl_object_lookup(obj, "algorithm")) != NULL) {
+		rule->algorithm_str = ucl_object_tostring(value);
+
+		if (rule->algorithm_str) {
+			if (g_ascii_strcasecmp(rule->algorithm_str, "old") == 0 ||
+				g_ascii_strcasecmp(rule->algorithm_str, "siphash") == 0) {
+				rule->alg = RSPAMD_SHINGLES_OLD;
+			}
+			else if (g_ascii_strcasecmp(rule->algorithm_str, "xxhash") == 0) {
+				rule->alg = RSPAMD_SHINGLES_XXHASH;
+			}
+			else if (g_ascii_strcasecmp(rule->algorithm_str, "mumhash") == 0) {
+				rule->alg = RSPAMD_SHINGLES_MUMHASH;
+			}
+			else if (g_ascii_strcasecmp(rule->algorithm_str, "fasthash") == 0 ||
+					 g_ascii_strcasecmp(rule->algorithm_str, "fast") == 0) {
+				rule->alg = RSPAMD_SHINGLES_FAST;
+			}
+			else {
+				msg_warn_config("unknown algorithm: %s, use siphash by default",
+								rule->algorithm_str);
+			}
+		}
+	}
+
+	/* Set a consistent and short string name */
+	switch (rule->alg) {
+	case RSPAMD_SHINGLES_OLD:
+		rule->algorithm_str = "sip";
+		break;
+	case RSPAMD_SHINGLES_XXHASH:
+		rule->algorithm_str = "xx";
+		break;
+	case RSPAMD_SHINGLES_MUMHASH:
+		rule->algorithm_str = "mum";
+		break;
+	case RSPAMD_SHINGLES_FAST:
+		rule->algorithm_str = "fast";
+		break;
+	}
+
+	if ((value = ucl_object_lookup(obj, "servers")) != NULL) {
+		rule->servers = rspamd_upstreams_create(cfg->ups_ctx);
+		/* pass max_error and revive_time configuration in upstream for fuzzy storage
+		 * it allows to configure error_rate threshold and upstream dead timer
+		 */
+		rspamd_upstreams_set_limits(rule->servers,
+									(gdouble) fuzzy_module_ctx->revive_time, NAN, NAN, NAN,
+									(guint) fuzzy_module_ctx->max_errors, 0);
+
+		rspamd_mempool_add_destructor(cfg->cfg_pool,
+									  (rspamd_mempool_destruct_t) rspamd_upstreams_destroy,
+									  rule->servers);
+		if (!rspamd_upstreams_from_ucl(rule->servers, value, DEFAULT_PORT, NULL)) {
+			msg_err_config("cannot read servers definition");
+			return -1;
+		}
+	}
+	if ((value = ucl_object_lookup(obj, "fuzzy_map")) != NULL) {
+		it = NULL;
+		while ((cur = ucl_object_iterate(value, &it, true)) != NULL) {
+			parse_flags(rule, cfg, cur, cb_id);
+		}
+	}
+
+	if ((value = ucl_object_lookup(obj, "encryption_key")) != NULL) {
+		/* Create key from user's input */
+		k = ucl_object_tostring(value);
+
+		if (k == NULL || (rule->peer_key =
+							  rspamd_pubkey_from_base32(k, 0, RSPAMD_KEYPAIR_KEX,
+														RSPAMD_CRYPTOBOX_MODE_25519)) == NULL) {
+			msg_err_config("bad encryption key value: %s",
+						   k);
+			return -1;
+		}
+
+		rule->local_key = rspamd_keypair_new(RSPAMD_KEYPAIR_KEX,
+											 RSPAMD_CRYPTOBOX_MODE_25519);
+	}
+
+	if ((value = ucl_object_lookup(obj, "learn_condition")) != NULL) {
+		lua_script = ucl_object_tostring(value);
+
+		if (lua_script) {
+			if (luaL_dostring(cfg->lua_state, lua_script) != 0) {
+				msg_err_config("cannot execute lua script for fuzzy "
+							   "learn condition: %s",
+							   lua_tostring(cfg->lua_state, -1));
+			}
+			else {
+				if (lua_type(cfg->lua_state, -1) == LUA_TFUNCTION) {
+					rule->learn_condition_cb = luaL_ref(cfg->lua_state,
+														LUA_REGISTRYINDEX);
+					msg_info_config("loaded learn condition script for fuzzy rule:"
+									" %s",
+									rule->name);
+				}
+				else {
+					msg_err_config("lua script must return "
+								   "function(task) and not %s",
+								   lua_typename(cfg->lua_state,
+												lua_type(cfg->lua_state, -1)));
+				}
+			}
+		}
+	}
+
+	key_str = NULL;
+	if ((value = ucl_object_lookup(obj, "fuzzy_key")) != NULL) {
+		/* Create key from user's input */
+		key_str = ucl_object_tostring(value);
+	}
+
+	/* Setup keys */
+	if (key_str == NULL) {
+		/* Use some default key for all ops */
+		key_str = "rspamd";
+	}
+
+	rule->hash_key = g_string_sized_new(rspamd_cryptobox_HASHBYTES);
+	rspamd_cryptobox_hash(rule->hash_key->str, key_str, strlen(key_str), NULL, 0);
+	rule->hash_key->len = rspamd_cryptobox_HASHKEYBYTES;
+
+	shingles_key_str = NULL;
+	if ((value = ucl_object_lookup(obj, "fuzzy_shingles_key")) != NULL) {
+		shingles_key_str = ucl_object_tostring(value);
+	}
+	if (shingles_key_str == NULL) {
+		shingles_key_str = "rspamd";
+	}
+
+	rule->shingles_key = g_string_sized_new(rspamd_cryptobox_HASHBYTES);
+	rspamd_cryptobox_hash(rule->shingles_key->str, shingles_key_str,
+						  strlen(shingles_key_str), NULL, 0);
+	rule->shingles_key->len = 16;
+
+	if (rspamd_upstreams_count(rule->servers) == 0) {
+		msg_err_config("no servers defined for fuzzy rule with name: %s",
+					   rule->name);
+		return -1;
+	}
+	else {
+		g_ptr_array_add(fuzzy_module_ctx->fuzzy_rules, rule);
+
+		if (rule->symbol != fuzzy_module_ctx->default_symbol) {
+			int vid = rspamd_symcache_add_symbol(cfg->cache, rule->symbol,
+												 0,
+												 NULL, NULL,
+												 SYMBOL_TYPE_VIRTUAL | SYMBOL_TYPE_FINE,
+												 cb_id);
+
+			if (rule->io_timeout > 0) {
+				char timeout_buf[32];
+				rspamd_snprintf(timeout_buf, sizeof(timeout_buf), "%f",
+								rule->io_timeout);
+				rspamd_symcache_add_symbol_augmentation(cfg->cache,
+														vid, "timeout",
+														timeout_buf);
+			}
+		}
+
+		msg_info_config("added fuzzy rule %s, key: %*xs, "
+						"shingles_key: %*xs, algorithm: %s",
+						rule->symbol,
+						6, rule->hash_key->str,
+						6, rule->shingles_key->str,
+						rule->algorithm_str);
+	}
+
+	if ((value = ucl_object_lookup(obj, "weight_threshold")) != NULL) {
+		rule->weight_threshold = ucl_object_todouble(value);
+	}
+
+	/*
+	 * Process rule in Lua
+	 */
+	gint err_idx, ret;
+	lua_State *L = (lua_State *) cfg->lua_state;
+
+	lua_pushcfunction(L, &rspamd_lua_traceback);
+	err_idx = lua_gettop(L);
+	lua_rawgeti(L, LUA_REGISTRYINDEX, fuzzy_module_ctx->process_rule_ref);
+	ucl_object_push_lua(L, obj, true);
+
+	if ((ret = lua_pcall(L, 1, 1, err_idx)) != 0) {
+		msg_err_config("call to process_rule lua "
+					   "script failed (%d): %s",
+					   ret, lua_tostring(L, -1));
+
+		rule->lua_id = -1;
+	}
+	else {
+		rule->lua_id = lua_tonumber(L, -1);
+	}
+
+	lua_settop(L, err_idx - 1);
+
+	rspamd_mempool_add_destructor(cfg->cfg_pool, fuzzy_free_rule,
+								  rule);
+
+	return 0;
+}
+
+gint fuzzy_check_module_init(struct rspamd_config *cfg, struct module_ctx **ctx)
+{
+	struct fuzzy_ctx *fuzzy_module_ctx;
+
+	fuzzy_module_ctx = rspamd_mempool_alloc0(cfg->cfg_pool,
+											 sizeof(struct fuzzy_ctx));
+
+	fuzzy_module_ctx->fuzzy_pool = rspamd_mempool_new(rspamd_mempool_suggest_size(),
+													  NULL, 0);
+	/* TODO: this should match rules count actually */
+	fuzzy_module_ctx->keypairs_cache = rspamd_keypair_cache_new(32);
+	fuzzy_module_ctx->fuzzy_rules = g_ptr_array_new();
+	fuzzy_module_ctx->cfg = cfg;
+	fuzzy_module_ctx->process_rule_ref = -1;
+	fuzzy_module_ctx->check_mime_part_ref = -1;
+	fuzzy_module_ctx->cleanup_rules_ref = -1;
+
+	rspamd_mempool_add_destructor(cfg->cfg_pool,
+								  (rspamd_mempool_destruct_t) rspamd_mempool_delete,
+								  fuzzy_module_ctx->fuzzy_pool);
+	rspamd_mempool_add_destructor(cfg->cfg_pool,
+								  (rspamd_mempool_destruct_t) rspamd_keypair_cache_destroy,
+								  fuzzy_module_ctx->keypairs_cache);
+	rspamd_mempool_add_destructor(cfg->cfg_pool,
+								  (rspamd_mempool_destruct_t) rspamd_ptr_array_free_hard,
+								  fuzzy_module_ctx->fuzzy_rules);
+
+	*ctx = (struct module_ctx *) fuzzy_module_ctx;
+
+	rspamd_rcl_add_doc_by_path(cfg,
+							   NULL,
+							   "Fuzzy check plugin",
+							   "fuzzy_check",
+							   UCL_OBJECT,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check",
+							   "Default symbol",
+							   "symbol",
+							   UCL_STRING,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check",
+							   "Minimum number of *words* to check a text part",
+							   "min_length",
+							   UCL_INT,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check",
+							   "Minimum number of *bytes* to check a non-text part",
+							   "min_bytes",
+							   UCL_INT,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check",
+							   "Multiplier for bytes limit when checking for text parts",
+							   "text_multiplier",
+							   UCL_FLOAT,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check",
+							   "Minimum height in pixels for embedded images to check using fuzzy storage",
+							   "min_height",
+							   UCL_INT,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check",
+							   "Minimum width in pixels for embedded images to check using fuzzy storage",
+							   "min_width",
+							   UCL_INT,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check",
+							   "Timeout for waiting reply from a fuzzy server",
+							   "timeout",
+							   UCL_TIME,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check",
+							   "Maximum number of retransmits for a single request",
+							   "retransmits",
+							   UCL_INT,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check",
+							   "Maximum number of upstream errors, affects error rate threshold",
+							   "max_errors",
+							   UCL_INT,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check",
+							   "Time to lapse before re-resolve faulty upstream",
+							   "revive_time",
+							   UCL_FLOAT,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check",
+							   "Whitelisted IPs map",
+							   "whitelist",
+							   UCL_STRING,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	/* Rules doc strings */
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check",
+							   "Fuzzy check rule",
+							   "rule",
+							   UCL_OBJECT,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule",
+							   "Headers that are used to make a separate hash",
+							   "headers",
+							   UCL_ARRAY,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule",
+							   "Whitelisted hashes map",
+							   "skip_hashes",
+							   UCL_STRING,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule",
+							   "Set of mime types (in form type/subtype, or type/*, or *) to check with fuzzy",
+							   "mime_types",
+							   UCL_ARRAY,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule",
+							   "Maximum value for fuzzy hash when weight of symbol is exactly 1.0 (if value is higher then score is still 1.0)",
+							   "max_score",
+							   UCL_INT,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule",
+							   "List of servers to check (or learn)",
+							   "servers",
+							   UCL_STRING,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule",
+							   "If true then never try to learn this fuzzy storage",
+							   "read_only",
+							   UCL_BOOLEAN,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule",
+							   "If true then ignore unknown flags and not add the default fuzzy symbol",
+							   "skip_unknown",
+							   UCL_BOOLEAN,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule",
+							   "Default symbol for rule (if no flags defined or matched)",
+							   "symbol",
+							   UCL_STRING,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule",
+							   "Base32 value for the protocol encryption public key",
+							   "encryption_key",
+							   UCL_STRING,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule",
+							   "Base32 value for the hashing key (for private storages)",
+							   "fuzzy_key",
+							   UCL_STRING,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule",
+							   "Base32 value for the shingles hashing key (for private storages)",
+							   "fuzzy_shingles_key",
+							   UCL_STRING,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule",
+							   "Lua script that returns boolean function to check if this task "
+							   "should be considered when learning fuzzy storage",
+							   "learn_condition",
+							   UCL_STRING,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule",
+							   "Map of SYMBOL -> data for flags configuration",
+							   "fuzzy_map",
+							   UCL_OBJECT,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule",
+							   "Use direct hash for short texts",
+							   "short_text_direct_hash",
+							   UCL_BOOLEAN,
+							   NULL,
+							   0,
+							   "true",
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule",
+							   "Override module default min bytes for this rule",
+							   "min_bytes",
+							   UCL_INT,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	/* Fuzzy map doc strings */
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule.fuzzy_map",
+							   "Maximum score for this flag",
+							   "max_score",
+							   UCL_INT,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule.fuzzy_map",
+							   "Flag number",
+							   "flag",
+							   UCL_INT,
+							   NULL,
+							   0,
+							   NULL,
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule",
+							   "Do no use subject to distinguish short text hashes",
+							   "no_subject",
+							   UCL_BOOLEAN,
+							   NULL,
+							   0,
+							   "false",
+							   0);
+	rspamd_rcl_add_doc_by_path(cfg,
+							   "fuzzy_check.rule",
+							   "Disable sharing message stats with the fuzzy server",
+							   "no_share",
+							   UCL_BOOLEAN,
+							   NULL,
+							   0,
+							   "false",
+							   0);
+
+	return 0;
+}
+
+gint fuzzy_check_module_config(struct rspamd_config *cfg, bool validate)
+{
+	const ucl_object_t *value, *cur, *elt;
+	ucl_object_iter_t it;
+	gint res = TRUE, cb_id, nrules = 0;
+	lua_State *L = cfg->lua_state;
+	struct fuzzy_ctx *fuzzy_module_ctx = fuzzy_get_context(cfg);
+
+	if (!rspamd_config_is_module_enabled(cfg, "fuzzy_check")) {
+		return TRUE;
+	}
+
+	fuzzy_module_ctx->enabled = TRUE;
+	fuzzy_module_ctx->check_mime_part_ref = -1;
+	fuzzy_module_ctx->process_rule_ref = -1;
+	fuzzy_module_ctx->cleanup_rules_ref = -1;
+
+	/* Interact with lua_fuzzy */
+	if (luaL_dostring(L, "return require \"lua_fuzzy\"") != 0) {
+		msg_err_config("cannot require lua_fuzzy: %s",
+					   lua_tostring(L, -1));
+		fuzzy_module_ctx->enabled = FALSE;
+	}
+	else {
+#if LUA_VERSION_NUM >= 504
+		lua_settop(L, -2);
+#endif
+		if (lua_type(L, -1) != LUA_TTABLE) {
+			msg_err_config("lua fuzzy must return "
+						   "table and not %s",
+						   lua_typename(L, lua_type(L, -1)));
+			fuzzy_module_ctx->enabled = FALSE;
+		}
+		else {
+			lua_pushstring(L, "process_rule");
+			lua_gettable(L, -2);
+
+			if (lua_type(L, -1) != LUA_TFUNCTION) {
+				msg_err_config("process_rule must return "
+							   "function and not %s",
+							   lua_typename(L, lua_type(L, -1)));
+				fuzzy_module_ctx->enabled = FALSE;
+			}
+			else {
+				fuzzy_module_ctx->process_rule_ref = luaL_ref(L, LUA_REGISTRYINDEX);
+			}
+
+			lua_pushstring(L, "check_mime_part");
+			lua_gettable(L, -2);
+
+			if (lua_type(L, -1) != LUA_TFUNCTION) {
+				msg_err_config("check_mime_part must return "
+							   "function and not %s",
+							   lua_typename(L, lua_type(L, -1)));
+				fuzzy_module_ctx->enabled = FALSE;
+			}
+			else {
+				fuzzy_module_ctx->check_mime_part_ref = luaL_ref(L, LUA_REGISTRYINDEX);
+			}
+
+			lua_pushstring(L, "cleanup_rules");
+			lua_gettable(L, -2);
+
+			if (lua_type(L, -1) != LUA_TFUNCTION) {
+				msg_err_config("cleanup_rules must return "
+							   "function and not %s",
+							   lua_typename(L, lua_type(L, -1)));
+				fuzzy_module_ctx->enabled = FALSE;
+			}
+			else {
+				fuzzy_module_ctx->cleanup_rules_ref = luaL_ref(L, LUA_REGISTRYINDEX);
+			}
+		}
+	}
+
+	lua_settop(L, 0);
+
+	if (!fuzzy_module_ctx->enabled) {
+		return TRUE;
+	}
+
+	if ((value =
+			 rspamd_config_get_module_opt(cfg, "fuzzy_check", "symbol")) != NULL) {
+		fuzzy_module_ctx->default_symbol = ucl_obj_tostring(value);
+	}
+	else {
+		fuzzy_module_ctx->default_symbol = DEFAULT_SYMBOL;
+	}
+
+	if ((value =
+			 rspamd_config_get_module_opt(cfg, "fuzzy_check", "timeout")) != NULL) {
+		fuzzy_module_ctx->io_timeout = ucl_obj_todouble(value);
+	}
+	else {
+		fuzzy_module_ctx->io_timeout = DEFAULT_IO_TIMEOUT;
+	}
+
+	if ((value =
+			 rspamd_config_get_module_opt(cfg,
+										  "fuzzy_check",
+										  "retransmits")) != NULL) {
+		fuzzy_module_ctx->retransmits = ucl_obj_toint(value);
+	}
+	else {
+		fuzzy_module_ctx->retransmits = DEFAULT_RETRANSMITS;
+	}
+
+	if ((value =
+			 rspamd_config_get_module_opt(cfg, "fuzzy_check",
+										  "max_errors")) != NULL) {
+		fuzzy_module_ctx->max_errors = ucl_obj_toint(value);
+	}
+	else {
+		fuzzy_module_ctx->max_errors = DEFAULT_MAX_ERRORS;
+	}
+
+	if ((value =
+			 rspamd_config_get_module_opt(cfg, "fuzzy_check",
+										  "revive_time")) != NULL) {
+		fuzzy_module_ctx->revive_time = ucl_obj_todouble(value);
+	}
+	else {
+		fuzzy_module_ctx->revive_time = DEFAULT_REVIVE_TIME;
+	}
+
+	if ((value =
+			 rspamd_config_get_module_opt(cfg, "fuzzy_check",
+										  "whitelist")) != NULL) {
+		rspamd_config_radix_from_ucl(cfg, value, "Fuzzy whitelist",
+									 &fuzzy_module_ctx->whitelist,
+									 NULL,
+									 NULL, "fuzzy ip whitelist");
+	}
+	else {
+		fuzzy_module_ctx->whitelist = NULL;
+	}
+
+	if ((value =
+			 rspamd_config_get_module_opt(cfg, "fuzzy_check", "rule")) != NULL) {
+
+		cb_id = rspamd_symcache_add_symbol(cfg->cache,
+										   "FUZZY_CALLBACK", 0, fuzzy_symbol_callback, NULL,
+										   SYMBOL_TYPE_CALLBACK | SYMBOL_TYPE_FINE,
+										   -1);
+		rspamd_config_add_symbol(cfg,
+								 "FUZZY_CALLBACK",
+								 0.0,
+								 "Fuzzy check callback",
+								 "fuzzy",
+								 RSPAMD_SYMBOL_FLAG_IGNORE_METRIC,
+								 1,
+								 1);
+
+		/*
+		 * Here we can have 2 possibilities:
+		 *
+		 * unnamed rules:
+		 *
+		 * rule {
+		 * ...
+		 * }
+		 * rule {
+		 * ...
+		 * }
+		 *
+		 * - or - named rules:
+		 *
+		 * rule {
+		 * 	"rule1": {
+		 * 	...
+		 * 	}
+		 * 	"rule2": {
+		 * 	...
+		 * 	}
+		 * }
+		 *
+		 * So, for each element, we check, if there 'servers' key. If 'servers' is
+		 * presented, then we treat it as unnamed rule, otherwise we treat it as
+		 * named rule.
+		 */
+		LL_FOREACH(value, cur)
+		{
+
+			if (ucl_object_lookup(cur, "servers")) {
+				/* Unnamed rule */
+				fuzzy_parse_rule(cfg, cur, NULL, cb_id);
+				nrules++;
+			}
+			else {
+				/* Named rule */
+				it = NULL;
+
+				while ((elt = ucl_object_iterate(cur, &it, true)) != NULL) {
+					fuzzy_parse_rule(cfg, elt, ucl_object_key(elt), cb_id);
+					nrules++;
+				}
+			}
+		}
+
+		/* We want that to check bad mime attachments */
+		rspamd_symcache_add_delayed_dependency(cfg->cache,
+											   "FUZZY_CALLBACK", "MIME_TYPES_CALLBACK");
+	}
+
+	if (fuzzy_module_ctx->fuzzy_rules == NULL) {
+		msg_warn_config("fuzzy module is enabled but no rules are defined");
+	}
+
+	msg_info_config("init internal fuzzy_check module, %d rules loaded",
+					nrules);
+
+	/* Register global methods */
+	lua_getglobal(L, "rspamd_plugins");
+
+	if (lua_type(L, -1) == LUA_TTABLE) {
+		lua_pushstring(L, "fuzzy_check");
+		lua_createtable(L, 0, 3);
+		/* Set methods */
+		lua_pushstring(L, "unlearn");
+		lua_pushcfunction(L, fuzzy_lua_unlearn_handler);
+		lua_settable(L, -3);
+		lua_pushstring(L, "learn");
+		lua_pushcfunction(L, fuzzy_lua_learn_handler);
+		lua_settable(L, -3);
+		lua_pushstring(L, "gen_hashes");
+		lua_pushcfunction(L, fuzzy_lua_gen_hashes_handler);
+		lua_settable(L, -3);
+		lua_pushstring(L, "hex_hashes");
+		lua_pushcfunction(L, fuzzy_lua_hex_hashes_handler);
+		lua_settable(L, -3);
+		lua_pushstring(L, "list_storages");
+		lua_pushcfunction(L, fuzzy_lua_list_storages);
+		lua_settable(L, -3);
+		lua_pushstring(L, "ping_storage");
+		lua_pushcfunction(L, fuzzy_lua_ping_storage);
+		lua_settable(L, -3);
+		/* Finish fuzzy_check key */
+		lua_settable(L, -3);
+	}
+
+	lua_settop(L, 0);
+
+	return res;
+}
+
+gint fuzzy_check_module_reconfig(struct rspamd_config *cfg)
+{
+	struct fuzzy_ctx *fuzzy_module_ctx = fuzzy_get_context(cfg);
+
+	if (fuzzy_module_ctx->cleanup_rules_ref != -1) {
+		/* Sync lua_fuzzy rules */
+		gint err_idx, ret;
+		lua_State *L = (lua_State *) cfg->lua_state;
+
+		lua_pushcfunction(L, &rspamd_lua_traceback);
+		err_idx = lua_gettop(L);
+		lua_rawgeti(L, LUA_REGISTRYINDEX, fuzzy_module_ctx->cleanup_rules_ref);
+
+		if ((ret = lua_pcall(L, 0, 0, err_idx)) != 0) {
+			msg_err_config("call to cleanup_rules lua "
+						   "script failed (%d): %s",
+						   ret, lua_tostring(L, -1));
+		}
+
+		luaL_unref(cfg->lua_state, LUA_REGISTRYINDEX,
+				   fuzzy_module_ctx->cleanup_rules_ref);
+		lua_settop(L, 0);
+	}
+
+	if (fuzzy_module_ctx->check_mime_part_ref != -1) {
+		luaL_unref(cfg->lua_state, LUA_REGISTRYINDEX,
+				   fuzzy_module_ctx->check_mime_part_ref);
+	}
+
+	if (fuzzy_module_ctx->process_rule_ref != -1) {
+		luaL_unref(cfg->lua_state, LUA_REGISTRYINDEX,
+				   fuzzy_module_ctx->process_rule_ref);
+	}
+
+	return fuzzy_check_module_config(cfg, false);
+}
+
+/* Finalize IO */
+static void
+fuzzy_io_fin(void *ud)
+{
+	struct fuzzy_client_session *session = ud;
+
+	if (session->commands) {
+		g_ptr_array_free(session->commands, TRUE);
+	}
+
+	if (session->results) {
+		g_ptr_array_free(session->results, TRUE);
+	}
+
+	rspamd_ev_watcher_stop(session->event_loop, &session->ev);
+	close(session->fd);
+}
+
+static GArray *
+fuzzy_preprocess_words(struct rspamd_mime_text_part *part, rspamd_mempool_t *pool)
+{
+	return part->utf_words;
+}
+
+static void
+fuzzy_encrypt_cmd(struct fuzzy_rule *rule,
+				  struct rspamd_fuzzy_encrypted_req_hdr *hdr,
+				  guchar *data, gsize datalen)
+{
+	const guchar *pk;
+	guint pklen;
+
+	g_assert(hdr != NULL);
+	g_assert(data != NULL);
+	g_assert(rule != NULL);
+
+	/* Encrypt data */
+	memcpy(hdr->magic,
+		   fuzzy_encrypted_magic,
+		   sizeof(hdr->magic));
+	ottery_rand_bytes(hdr->nonce, sizeof(hdr->nonce));
+	pk = rspamd_keypair_component(rule->local_key,
+								  RSPAMD_KEYPAIR_COMPONENT_PK, &pklen);
+	memcpy(hdr->pubkey, pk, MIN(pklen, sizeof(hdr->pubkey)));
+	pk = rspamd_pubkey_get_pk(rule->peer_key, &pklen);
+	memcpy(hdr->key_id, pk, MIN(sizeof(hdr->key_id), pklen));
+	rspamd_keypair_cache_process(rule->ctx->keypairs_cache,
+								 rule->local_key, rule->peer_key);
+	rspamd_cryptobox_encrypt_nm_inplace(data, datalen,
+										hdr->nonce, rspamd_pubkey_get_nm(rule->peer_key, rule->local_key),
+										hdr->mac,
+										rspamd_pubkey_alg(rule->peer_key));
+}
+
+static struct fuzzy_cmd_io *
+fuzzy_cmd_stat(struct fuzzy_rule *rule,
+			   int c,
+			   gint flag,
+			   guint32 weight,
+			   rspamd_mempool_t *pool)
+{
+	struct rspamd_fuzzy_cmd *cmd;
+	struct rspamd_fuzzy_encrypted_cmd *enccmd = NULL;
+	struct fuzzy_cmd_io *io;
+
+	if (rule->peer_key) {
+		enccmd = rspamd_mempool_alloc0(pool, sizeof(*enccmd));
+		cmd = &enccmd->cmd;
+	}
+	else {
+		cmd = rspamd_mempool_alloc0(pool, sizeof(*cmd));
+	}
+
+	cmd->cmd = c;
+	cmd->version = RSPAMD_FUZZY_PLUGIN_VERSION;
+	cmd->shingles_count = 0;
+	cmd->tag = ottery_rand_uint32();
+
+	io = rspamd_mempool_alloc(pool, sizeof(*io));
+	io->flags = 0;
+	io->tag = cmd->tag;
+	memcpy(&io->cmd, cmd, sizeof(io->cmd));
+
+	if (rule->peer_key && enccmd) {
+		fuzzy_encrypt_cmd(rule, &enccmd->hdr, (guchar *) cmd, sizeof(*cmd));
+		io->io.iov_base = enccmd;
+		io->io.iov_len = sizeof(*enccmd);
+	}
+	else {
+		io->io.iov_base = cmd;
+		io->io.iov_len = sizeof(*cmd);
+	}
+
+	return io;
+}
+
+static inline double
+fuzzy_milliseconds_since_midnight(void)
+{
+	double now = rspamd_get_calendar_ticks();
+	double ms = now - (int64_t) now;
+	now = (((int64_t) now % 86400) + ms) * 1000;
+
+	return now;
+}
+
+static struct fuzzy_cmd_io *
+fuzzy_cmd_ping(struct fuzzy_rule *rule,
+			   rspamd_mempool_t *pool)
+{
+	struct rspamd_fuzzy_cmd *cmd;
+	struct rspamd_fuzzy_encrypted_cmd *enccmd = NULL;
+	struct fuzzy_cmd_io *io;
+
+	if (rule->peer_key) {
+		enccmd = rspamd_mempool_alloc0(pool, sizeof(*enccmd));
+		cmd = &enccmd->cmd;
+	}
+	else {
+		cmd = rspamd_mempool_alloc0(pool, sizeof(*cmd));
+	}
+
+	/* Get milliseconds since midnight */
+
+
+	cmd->cmd = FUZZY_PING;
+	cmd->version = RSPAMD_FUZZY_PLUGIN_VERSION;
+	cmd->shingles_count = 0;
+	cmd->value = fuzzy_milliseconds_since_midnight(); /* Record timestamp */
+	cmd->tag = ottery_rand_uint32();
+
+	io = rspamd_mempool_alloc(pool, sizeof(*io));
+	io->flags = 0;
+	io->tag = cmd->tag;
+	memcpy(&io->cmd, cmd, sizeof(io->cmd));
+
+	if (rule->peer_key && enccmd) {
+		fuzzy_encrypt_cmd(rule, &enccmd->hdr, (guchar *) cmd, sizeof(*cmd));
+		io->io.iov_base = enccmd;
+		io->io.iov_len = sizeof(*enccmd);
+	}
+	else {
+		io->io.iov_base = cmd;
+		io->io.iov_len = sizeof(*cmd);
+	}
+
+	return io;
+}
+
+static struct fuzzy_cmd_io *
+fuzzy_cmd_hash(struct fuzzy_rule *rule,
+			   int c,
+			   const rspamd_ftok_t *hash,
+			   gint flag,
+			   guint32 weight,
+			   rspamd_mempool_t *pool)
+{
+	struct rspamd_fuzzy_cmd *cmd;
+	struct rspamd_fuzzy_encrypted_cmd *enccmd = NULL;
+	struct fuzzy_cmd_io *io;
+
+	if (rule->peer_key) {
+		enccmd = rspamd_mempool_alloc0(pool, sizeof(*enccmd));
+		cmd = &enccmd->cmd;
+	}
+	else {
+		cmd = rspamd_mempool_alloc0(pool, sizeof(*cmd));
+	}
+
+	if (hash->len == sizeof(cmd->digest) * 2) {
+		/* It is hex encoding */
+		if (rspamd_decode_hex_buf(hash->begin, hash->len, cmd->digest,
+								  sizeof(cmd->digest)) == -1) {
+			msg_err_pool("cannot decode hash, wrong encoding");
+			return NULL;
+		}
+	}
+	else {
+		msg_err_pool("cannot decode hash, wrong length: %z", hash->len);
+		return NULL;
+	}
+
+	cmd->cmd = c;
+	cmd->version = RSPAMD_FUZZY_PLUGIN_VERSION;
+	cmd->shingles_count = 0;
+	cmd->tag = ottery_rand_uint32();
+
+	io = rspamd_mempool_alloc(pool, sizeof(*io));
+	io->flags = 0;
+	io->tag = cmd->tag;
+
+	memcpy(&io->cmd, cmd, sizeof(io->cmd));
+
+	if (rule->peer_key && enccmd) {
+		fuzzy_encrypt_cmd(rule, &enccmd->hdr, (guchar *) cmd, sizeof(*cmd));
+		io->io.iov_base = enccmd;
+		io->io.iov_len = sizeof(*enccmd);
+	}
+	else {
+		io->io.iov_base = cmd;
+		io->io.iov_len = sizeof(*cmd);
+	}
+
+	return io;
+}
+
+struct rspamd_cached_shingles {
+	struct rspamd_shingle *sh;
+	guchar digest[rspamd_cryptobox_HASHBYTES];
+	guint additional_length;
+	guchar *additional_data;
+};
+
+
+static struct rspamd_cached_shingles *
+fuzzy_cmd_get_cached(struct fuzzy_rule *rule,
+					 struct rspamd_task *task,
+					 struct rspamd_mime_part *mp)
+{
+	gchar key[32];
+	gint key_part;
+	struct rspamd_cached_shingles **cached;
+
+	memcpy(&key_part, rule->shingles_key->str, sizeof(key_part));
+	rspamd_snprintf(key, sizeof(key), "%s%d", rule->algorithm_str,
+					key_part);
+
+	cached = (struct rspamd_cached_shingles **) rspamd_mempool_get_variable(
+		task->task_pool, key);
+
+	if (cached && cached[mp->part_number]) {
+		return cached[mp->part_number];
+	}
+
+	return NULL;
+}
+
+static void
+fuzzy_cmd_set_cached(struct fuzzy_rule *rule,
+					 struct rspamd_task *task,
+					 struct rspamd_mime_part *mp,
+					 struct rspamd_cached_shingles *data)
+{
+	gchar key[32];
+	gint key_part;
+	struct rspamd_cached_shingles **cached;
+
+	memcpy(&key_part, rule->shingles_key->str, sizeof(key_part));
+	rspamd_snprintf(key, sizeof(key), "%s%d", rule->algorithm_str,
+					key_part);
+
+	cached = (struct rspamd_cached_shingles **) rspamd_mempool_get_variable(
+		task->task_pool, key);
+
+	if (cached) {
+		cached[mp->part_number] = data;
+	}
+	else {
+		cached = rspamd_mempool_alloc0(task->task_pool, sizeof(*cached) *
+															(MESSAGE_FIELD(task, parts)->len + 1));
+		cached[mp->part_number] = data;
+
+		rspamd_mempool_set_variable(task->task_pool, key, cached, NULL);
+	}
+}
+
+static gboolean
+fuzzy_rule_check_mimepart(struct rspamd_task *task,
+						  struct fuzzy_rule *rule,
+						  struct rspamd_mime_part *part,
+						  gboolean *need_check,
+						  gboolean *fuzzy_check)
+{
+	lua_State *L = (lua_State *) task->cfg->lua_state;
+
+	gint old_top = lua_gettop(L);
+
+	if (rule->lua_id != -1 && rule->ctx->check_mime_part_ref != -1) {
+		gint err_idx, ret;
+
+		struct rspamd_task **ptask;
+		struct rspamd_mime_part **ppart;
+
+		lua_pushcfunction(L, &rspamd_lua_traceback);
+		err_idx = lua_gettop(L);
+		lua_rawgeti(L, LUA_REGISTRYINDEX, rule->ctx->check_mime_part_ref);
+
+		ptask = lua_newuserdata(L, sizeof(*ptask));
+		*ptask = task;
+		rspamd_lua_setclass(L, "rspamd{task}", -1);
+
+		ppart = lua_newuserdata(L, sizeof(*ppart));
+		*ppart = part;
+		rspamd_lua_setclass(L, "rspamd{mimepart}", -1);
+
+		lua_pushnumber(L, rule->lua_id);
+
+		if ((ret = lua_pcall(L, 3, 2, err_idx)) != 0) {
+			msg_err_task("call to check_mime_part lua "
+						 "script failed (%d): %s",
+						 ret, lua_tostring(L, -1));
+
+			ret = FALSE;
+		}
+		else {
+			ret = TRUE;
+			*need_check = lua_toboolean(L, -2);
+			*fuzzy_check = lua_toboolean(L, -1);
+		}
+
+		lua_settop(L, old_top);
+
+		return ret;
+	}
+
+	return FALSE;
+}
+
+#define MAX_FUZZY_DOMAIN 64
+
+static guint
+fuzzy_cmd_extension_length(struct rspamd_task *task,
+						   struct fuzzy_rule *rule)
+{
+	guint total = 0;
+
+	if (rule->no_share) {
+		return 0;
+	}
+
+	/* From domain */
+	if (MESSAGE_FIELD(task, from_mime) && MESSAGE_FIELD(task, from_mime)->len > 0) {
+		struct rspamd_email_address *addr = g_ptr_array_index(MESSAGE_FIELD(task,
+																			from_mime),
+															  0);
+
+		if (addr->domain_len > 0) {
+			total += 2; /* 2 bytes: type + length */
+			total += MIN(MAX_FUZZY_DOMAIN, addr->domain_len);
+		}
+	}
+
+	if (task->from_addr && rspamd_inet_address_get_af(task->from_addr) == AF_INET) {
+		total += sizeof(struct in_addr) + 1;
+	}
+	else if (task->from_addr && rspamd_inet_address_get_af(task->from_addr) == AF_INET6) {
+		total += sizeof(struct in6_addr) + 1;
+	}
+
+	return total;
+}
+
+static guint
+fuzzy_cmd_write_extensions(struct rspamd_task *task,
+						   struct fuzzy_rule *rule,
+						   guchar *dest,
+						   gsize available)
+{
+	guint written = 0;
+
+	if (rule->no_share) {
+		return 0;
+	}
+
+	if (MESSAGE_FIELD(task, from_mime) && MESSAGE_FIELD(task, from_mime)->len > 0) {
+		struct rspamd_email_address *addr = g_ptr_array_index(MESSAGE_FIELD(task,
+																			from_mime),
+															  0);
+		guint to_write = MIN(MAX_FUZZY_DOMAIN, addr->domain_len) + 2;
+
+		if (to_write > 0 && to_write <= available) {
+			*dest++ = RSPAMD_FUZZY_EXT_SOURCE_DOMAIN;
+			*dest++ = to_write - 2;
+
+			if (addr->domain_len < MAX_FUZZY_DOMAIN) {
+				memcpy(dest, addr->domain, addr->domain_len);
+				dest += addr->domain_len;
+			}
+			else {
+				/* Trim from left */
+				memcpy(dest,
+					   addr->domain + (addr->domain_len - MAX_FUZZY_DOMAIN),
+					   MAX_FUZZY_DOMAIN);
+				dest += MAX_FUZZY_DOMAIN;
+			}
+
+			available -= to_write;
+			written += to_write;
+		}
+	}
+
+	if (task->from_addr && rspamd_inet_address_get_af(task->from_addr) == AF_INET) {
+		if (available >= sizeof(struct in_addr) + 1) {
+			guint klen;
+			guchar *inet_data = rspamd_inet_address_get_hash_key(task->from_addr, &klen);
+
+			*dest++ = RSPAMD_FUZZY_EXT_SOURCE_IP4;
+
+			memcpy(dest, inet_data, klen);
+			dest += klen;
+
+			available -= klen + 1;
+			written += klen + 1;
+		}
+	}
+	else if (task->from_addr && rspamd_inet_address_get_af(task->from_addr) == AF_INET6) {
+		if (available >= sizeof(struct in6_addr) + 1) {
+			guint klen;
+			guchar *inet_data = rspamd_inet_address_get_hash_key(task->from_addr, &klen);
+
+			*dest++ = RSPAMD_FUZZY_EXT_SOURCE_IP6;
+
+			memcpy(dest, inet_data, klen);
+			dest += klen;
+
+			available -= klen + 1;
+			written += klen + 1;
+		}
+	}
+
+	return written;
+}
+
+/*
+ * Create fuzzy command from a text part
+ */
+static struct fuzzy_cmd_io *
+fuzzy_cmd_from_text_part(struct rspamd_task *task,
+						 struct fuzzy_rule *rule,
+						 int c,
+						 gint flag,
+						 guint32 weight,
+						 gboolean short_text,
+						 struct rspamd_mime_text_part *part,
+						 struct rspamd_mime_part *mp)
+{
+	struct rspamd_fuzzy_shingle_cmd *shcmd = NULL;
+	struct rspamd_fuzzy_cmd *cmd = NULL;
+	struct rspamd_fuzzy_encrypted_shingle_cmd *encshcmd = NULL;
+	struct rspamd_fuzzy_encrypted_cmd *enccmd = NULL;
+	struct rspamd_cached_shingles *cached = NULL;
+	struct rspamd_shingle *sh = NULL;
+	guint i;
+	rspamd_cryptobox_hash_state_t st;
+	rspamd_stat_token_t *word;
+	GArray *words;
+	struct fuzzy_cmd_io *io;
+	guint additional_length;
+	guchar *additional_data;
+
+	cached = fuzzy_cmd_get_cached(rule, task, mp);
+
+	/*
+	 * Important note:
+	 *
+	 * We assume that fuzzy io is a consistent memory layout to fit into
+	 * iov structure of size 1
+	 *
+	 * However, there are 4 possibilities:
+	 * 1) non encrypted, non shingle command - just one cmd
+	 * 2) encrypted, non shingle command - encryption hdr + cmd
+	 * 3) non encrypted, shingle command - cmd + shingle
+	 * 4) encrypted, shingle command - encryption hdr + cmd + shingle
+	 *
+	 * Extensions are always at the end, but since we also have caching (sigh, meh...)
+	 * then we have one piece that looks like cmd (+ shingle) + extensions
+	 * To encrypt it optionally we take this memory and prepend encryption header
+	 *
+	 * In case of cached version we do the same: allocate, copy from cached (including extra)
+	 * and optionally encrypt.
+	 *
+	 * However, there should be no extensions in case of unencrypted connection
+	 * (for sanity + privacy).
+	 */
+	if (cached) {
+		additional_length = cached->additional_length;
+		additional_data = cached->additional_data;
+
+		/* Copy cached */
+		if (short_text) {
+			enccmd = rspamd_mempool_alloc0(task->task_pool,
+										   sizeof(*enccmd) + additional_length);
+			cmd = &enccmd->cmd;
+			memcpy(cmd->digest, cached->digest,
+				   sizeof(cached->digest));
+			cmd->shingles_count = 0;
+			memcpy(((guchar *) enccmd) + sizeof(*enccmd), additional_data,
+				   additional_length);
+		}
+		else if (cached->sh) {
+			encshcmd = rspamd_mempool_alloc0(task->task_pool,
+											 additional_length + sizeof(*encshcmd));
+			shcmd = &encshcmd->cmd;
+			memcpy(&shcmd->sgl, cached->sh, sizeof(struct rspamd_shingle));
+			memcpy(shcmd->basic.digest, cached->digest,
+				   sizeof(cached->digest));
+			memcpy(((guchar *) encshcmd) + sizeof(*encshcmd), additional_data,
+				   additional_length);
+			shcmd->basic.shingles_count = RSPAMD_SHINGLE_SIZE;
+		}
+		else {
+			return NULL;
+		}
+	}
+	else {
+		additional_length = fuzzy_cmd_extension_length(task, rule);
+		cached = rspamd_mempool_alloc0(task->task_pool, sizeof(*cached) +
+															additional_length);
+		/*
+		 * Allocate extensions and never touch it except copying to avoid
+		 * occasional encryption
+		 */
+		cached->additional_length = additional_length;
+		cached->additional_data = ((guchar *) cached) + sizeof(*cached);
+
+		if (additional_length > 0) {
+			fuzzy_cmd_write_extensions(task, rule, cached->additional_data,
+									   additional_length);
+		}
+
+		if (short_text) {
+			enccmd = rspamd_mempool_alloc0(task->task_pool,
+										   sizeof(*enccmd) + additional_length);
+			cmd = &enccmd->cmd;
+			rspamd_cryptobox_hash_init(&st, rule->hash_key->str,
+									   rule->hash_key->len);
+
+			rspamd_cryptobox_hash_update(&st, part->utf_stripped_content->data,
+										 part->utf_stripped_content->len);
+
+			if (!rule->no_subject && (MESSAGE_FIELD(task, subject))) {
+				/* We also include subject */
+				rspamd_cryptobox_hash_update(&st, MESSAGE_FIELD(task, subject),
+											 strlen(MESSAGE_FIELD(task, subject)));
+			}
+
+			rspamd_cryptobox_hash_final(&st, cmd->digest);
+			memcpy(cached->digest, cmd->digest, sizeof(cached->digest));
+			cached->sh = NULL;
+
+			additional_data = ((guchar *) enccmd) + sizeof(*enccmd);
+			memcpy(additional_data, cached->additional_data, additional_length);
+		}
+		else {
+			encshcmd = rspamd_mempool_alloc0(task->task_pool,
+											 sizeof(*encshcmd) + additional_length);
+			shcmd = &encshcmd->cmd;
+
+			/*
+			 * Generate hash from all words in the part
+			 */
+			rspamd_cryptobox_hash_init(&st, rule->hash_key->str, rule->hash_key->len);
+			words = fuzzy_preprocess_words(part, task->task_pool);
+
+			for (i = 0; i < words->len; i++) {
+				word = &g_array_index(words, rspamd_stat_token_t, i);
+
+				if (!((word->flags & RSPAMD_STAT_TOKEN_FLAG_SKIPPED) || word->stemmed.len == 0)) {
+					rspamd_cryptobox_hash_update(&st, word->stemmed.begin,
+												 word->stemmed.len);
+				}
+			}
+
+			rspamd_cryptobox_hash_final(&st, shcmd->basic.digest);
+
+			msg_debug_task("loading shingles of type %s with key %*xs",
+						   rule->algorithm_str,
+						   16, rule->shingles_key->str);
+			sh = rspamd_shingles_from_text(words,
+										   rule->shingles_key->str, task->task_pool,
+										   rspamd_shingles_default_filter, NULL,
+										   rule->alg);
+			if (sh != NULL) {
+				memcpy(&shcmd->sgl, sh, sizeof(shcmd->sgl));
+				shcmd->basic.shingles_count = RSPAMD_SHINGLE_SIZE;
+			}
+			else {
+				/* No shingles, no check */
+				return NULL;
+			}
+
+			cached->sh = sh;
+			memcpy(cached->digest, shcmd->basic.digest, sizeof(cached->digest));
+			additional_data = ((guchar *) encshcmd) + sizeof(*encshcmd);
+			memcpy(additional_data, cached->additional_data, additional_length);
+		}
+
+		/*
+		 * We always save encrypted command as it can handle both
+		 * encrypted and unencrypted requests.
+		 *
+		 * Since it is copied when obtained from the cache, it is safe to use
+		 * it this way.
+		 */
+		fuzzy_cmd_set_cached(rule, task, mp, cached);
+	}
+
+	io = rspamd_mempool_alloc(task->task_pool, sizeof(*io));
+	io->part = mp;
+
+	if (!short_text) {
+		shcmd->basic.tag = ottery_rand_uint32();
+		shcmd->basic.cmd = c;
+		shcmd->basic.version = RSPAMD_FUZZY_PLUGIN_VERSION;
+
+		if (c != FUZZY_CHECK) {
+			shcmd->basic.flag = flag;
+			shcmd->basic.value = weight;
+		}
+		io->tag = shcmd->basic.tag;
+		memcpy(&io->cmd, &shcmd->basic, sizeof(io->cmd));
+	}
+	else {
+		cmd->tag = ottery_rand_uint32();
+		cmd->cmd = c;
+		cmd->version = RSPAMD_FUZZY_PLUGIN_VERSION;
+
+		if (c != FUZZY_CHECK) {
+			cmd->flag = flag;
+			cmd->value = weight;
+		}
+		io->tag = cmd->tag;
+		memcpy(&io->cmd, cmd, sizeof(io->cmd));
+	}
+
+	io->flags = 0;
+
+
+	if (rule->peer_key) {
+		/* Encrypt data */
+		if (!short_text) {
+			fuzzy_encrypt_cmd(rule, &encshcmd->hdr, (guchar *) shcmd,
+							  sizeof(*shcmd) + additional_length);
+			io->io.iov_base = encshcmd;
+			io->io.iov_len = sizeof(*encshcmd) + additional_length;
+		}
+		else {
+			fuzzy_encrypt_cmd(rule, &enccmd->hdr, (guchar *) cmd,
+							  sizeof(*cmd) + additional_length);
+			io->io.iov_base = enccmd;
+			io->io.iov_len = sizeof(*enccmd) + additional_length;
+		}
+	}
+	else {
+
+		if (!short_text) {
+			io->io.iov_base = shcmd;
+			io->io.iov_len = sizeof(*shcmd) + additional_length;
+		}
+		else {
+			io->io.iov_base = cmd;
+			io->io.iov_len = sizeof(*cmd) + additional_length;
+		}
+	}
+
+	return io;
+}
+
+#if 0
+static struct fuzzy_cmd_io *
+fuzzy_cmd_from_image_part (struct fuzzy_rule *rule,
+						   int c,
+						   gint flag,
+						   guint32 weight,
+						   struct rspamd_task *task,
+						   struct rspamd_image *img,
+						   struct rspamd_mime_part *mp)
+{
+	struct rspamd_fuzzy_shingle_cmd *shcmd;
+	struct rspamd_fuzzy_encrypted_shingle_cmd *encshcmd;
+	struct fuzzy_cmd_io *io;
+	struct rspamd_shingle *sh;
+	struct rspamd_cached_shingles *cached;
+
+	cached = fuzzy_cmd_get_cached (rule, task, mp);
+
+	if (cached) {
+		/* Copy cached */
+		encshcmd = rspamd_mempool_alloc0 (task->task_pool, sizeof (*encshcmd));
+		shcmd = &encshcmd->cmd;
+		memcpy (&shcmd->sgl, cached->sh, sizeof (struct rspamd_shingle));
+		memcpy (shcmd->basic.digest, cached->digest,
+				sizeof (cached->digest));
+		shcmd->basic.shingles_count = RSPAMD_SHINGLE_SIZE;
+	}
+	else {
+		encshcmd = rspamd_mempool_alloc0 (task->task_pool, sizeof (*encshcmd));
+		shcmd = &encshcmd->cmd;
+
+		/*
+		 * Generate shingles
+		 */
+		sh = rspamd_shingles_from_image (img->dct,
+				rule->shingles_key->str, task->task_pool,
+				rspamd_shingles_default_filter, NULL,
+				rule->alg);
+		if (sh != NULL) {
+			memcpy (&shcmd->sgl, sh->hashes, sizeof (shcmd->sgl));
+			shcmd->basic.shingles_count = RSPAMD_SHINGLE_SIZE;
+#if 0
+			for (unsigned int i = 0; i < RSPAMD_SHINGLE_SIZE; i ++) {
+				msg_err ("shingle %d: %L", i, sh->hashes[i]);
+			}
+#endif
+		}
+
+		rspamd_cryptobox_hash (shcmd->basic.digest,
+				(const guchar *)img->dct, RSPAMD_DCT_LEN / NBBY,
+				rule->hash_key->str, rule->hash_key->len);
+
+		msg_debug_task ("loading shingles of type %s with key %*xs",
+				rule->algorithm_str,
+				16, rule->shingles_key->str);
+
+		/*
+		 * We always save encrypted command as it can handle both
+		 * encrypted and unencrypted requests.
+		 *
+		 * Since it is copied when obtained from the cache, it is safe to use
+		 * it this way.
+		 */
+		cached = rspamd_mempool_alloc (task->task_pool, sizeof (*cached));
+		cached->sh = sh;
+		memcpy (cached->digest, shcmd->basic.digest, sizeof (cached->digest));
+		fuzzy_cmd_set_cached (rule, task, mp, cached);
+	}
+
+	shcmd->basic.tag = ottery_rand_uint32 ();
+	shcmd->basic.cmd = c;
+	shcmd->basic.version = RSPAMD_FUZZY_PLUGIN_VERSION;
+
+	if (c != FUZZY_CHECK) {
+		shcmd->basic.flag = flag;
+		shcmd->basic.value = weight;
+	}
+
+	io = rspamd_mempool_alloc (task->task_pool, sizeof (*io));
+	io->part = mp;
+	io->tag = shcmd->basic.tag;
+	io->flags = FUZZY_CMD_FLAG_IMAGE;
+	memcpy (&io->cmd, &shcmd->basic, sizeof (io->cmd));
+
+	if (rule->peer_key) {
+		/* Encrypt data */
+		fuzzy_encrypt_cmd (rule, &encshcmd->hdr, (guchar *) shcmd, sizeof (*shcmd));
+		io->io.iov_base = encshcmd;
+		io->io.iov_len = sizeof (*encshcmd);
+	}
+	else {
+		io->io.iov_base = shcmd;
+		io->io.iov_len = sizeof (*shcmd);
+	}
+
+	return io;
+}
+#endif
+
+static struct fuzzy_cmd_io *
+fuzzy_cmd_from_data_part(struct fuzzy_rule *rule,
+						 int c,
+						 gint flag,
+						 guint32 weight,
+						 struct rspamd_task *task,
+						 guchar digest[rspamd_cryptobox_HASHBYTES],
+						 struct rspamd_mime_part *mp)
+{
+	struct rspamd_fuzzy_cmd *cmd;
+	struct rspamd_fuzzy_encrypted_cmd *enccmd = NULL;
+	struct fuzzy_cmd_io *io;
+	guint additional_length;
+	guchar *additional_data;
+
+	additional_length = fuzzy_cmd_extension_length(task, rule);
+
+	if (rule->peer_key) {
+		enccmd = rspamd_mempool_alloc0(task->task_pool,
+									   sizeof(*enccmd) + additional_length);
+		cmd = &enccmd->cmd;
+		additional_data = ((guchar *) enccmd) + sizeof(*enccmd);
+	}
+	else {
+		cmd = rspamd_mempool_alloc0(task->task_pool,
+									sizeof(*cmd) + additional_length);
+		additional_data = ((guchar *) cmd) + sizeof(*cmd);
+	}
+
+	cmd->cmd = c;
+	cmd->version = RSPAMD_FUZZY_PLUGIN_VERSION;
+	if (c != FUZZY_CHECK) {
+		cmd->flag = flag;
+		cmd->value = weight;
+	}
+	cmd->shingles_count = 0;
+	cmd->tag = ottery_rand_uint32();
+	memcpy(cmd->digest, digest, sizeof(cmd->digest));
+
+	io = rspamd_mempool_alloc(task->task_pool, sizeof(*io));
+	io->flags = 0;
+	io->tag = cmd->tag;
+	io->part = mp;
+	memcpy(&io->cmd, cmd, sizeof(io->cmd));
+
+	if (additional_length > 0) {
+		fuzzy_cmd_write_extensions(task, rule, additional_data,
+								   additional_length);
+	}
+
+	if (rule->peer_key) {
+		g_assert(enccmd != NULL);
+		fuzzy_encrypt_cmd(rule, &enccmd->hdr, (guchar *) cmd,
+						  sizeof(*cmd) + additional_length);
+		io->io.iov_base = enccmd;
+		io->io.iov_len = sizeof(*enccmd) + additional_length;
+	}
+	else {
+		io->io.iov_base = cmd;
+		io->io.iov_len = sizeof(*cmd) + additional_length;
+	}
+
+	return io;
+}
+
+static gboolean
+fuzzy_cmd_to_wire(gint fd, struct iovec *io)
+{
+	struct msghdr msg;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.msg_iov = io;
+	msg.msg_iovlen = 1;
+
+	while (sendmsg(fd, &msg, 0) == -1) {
+		if (errno == EINTR) {
+			continue;
+		}
+		return FALSE;
+	}
+
+	return TRUE;
+}
+
+static gboolean
+fuzzy_cmd_vector_to_wire(gint fd, GPtrArray *v)
+{
+	guint i;
+	gboolean all_sent = TRUE, all_replied = TRUE;
+	struct fuzzy_cmd_io *io;
+	gboolean processed = FALSE;
+
+	/* First try to resend unsent commands */
+	for (i = 0; i < v->len; i++) {
+		io = g_ptr_array_index(v, i);
+
+		if (io->flags & FUZZY_CMD_FLAG_REPLIED) {
+			continue;
+		}
+
+		all_replied = FALSE;
+
+		if (!(io->flags & FUZZY_CMD_FLAG_SENT)) {
+			if (!fuzzy_cmd_to_wire(fd, &io->io)) {
+				return FALSE;
+			}
+			processed = TRUE;
+			io->flags |= FUZZY_CMD_FLAG_SENT;
+			all_sent = FALSE;
+		}
+	}
+
+	if (all_sent && !all_replied) {
+		/* Now try to resend each command in the vector */
+		for (i = 0; i < v->len; i++) {
+			io = g_ptr_array_index(v, i);
+
+			if (!(io->flags & FUZZY_CMD_FLAG_REPLIED)) {
+				io->flags &= ~FUZZY_CMD_FLAG_SENT;
+			}
+		}
+
+		return fuzzy_cmd_vector_to_wire(fd, v);
+	}
+
+	return processed;
+}
+
+/*
+ * Read replies one-by-one and remove them from req array
+ */
+static const struct rspamd_fuzzy_reply *
+fuzzy_process_reply(guchar **pos, gint *r, GPtrArray *req,
+					struct fuzzy_rule *rule, struct rspamd_fuzzy_cmd **pcmd,
+					struct fuzzy_cmd_io **pio)
+{
+	guchar *p = *pos;
+	gint remain = *r;
+	guint i, required_size;
+	struct fuzzy_cmd_io *io;
+	const struct rspamd_fuzzy_reply *rep;
+	struct rspamd_fuzzy_encrypted_reply encrep;
+	gboolean found = FALSE;
+
+	if (rule->peer_key) {
+		required_size = sizeof(encrep);
+	}
+	else {
+		required_size = sizeof(*rep);
+	}
+
+	if (remain <= 0 || (guint) remain < required_size) {
+		return NULL;
+	}
+
+	if (rule->peer_key) {
+		memcpy(&encrep, p, sizeof(encrep));
+		*pos += required_size;
+		*r -= required_size;
+
+		/* Try to decrypt reply */
+		rspamd_keypair_cache_process(rule->ctx->keypairs_cache,
+									 rule->local_key, rule->peer_key);
+
+		if (!rspamd_cryptobox_decrypt_nm_inplace((guchar *) &encrep.rep,
+												 sizeof(encrep.rep),
+												 encrep.hdr.nonce,
+												 rspamd_pubkey_get_nm(rule->peer_key, rule->local_key),
+												 encrep.hdr.mac,
+												 rspamd_pubkey_alg(rule->peer_key))) {
+			msg_info("cannot decrypt reply");
+			return NULL;
+		}
+
+		/* Copy decrypted over the input wire */
+		memcpy(p, &encrep.rep, sizeof(encrep.rep));
+	}
+	else {
+
+		*pos += required_size;
+		*r -= required_size;
+	}
+
+	rep = (const struct rspamd_fuzzy_reply *) p;
+	/*
+	 * Search for tag
+	 */
+	for (i = 0; i < req->len; i++) {
+		io = g_ptr_array_index(req, i);
+
+		if (io->tag == rep->v1.tag) {
+			if (!(io->flags & FUZZY_CMD_FLAG_REPLIED)) {
+				io->flags |= FUZZY_CMD_FLAG_REPLIED;
+
+				if (pcmd) {
+					*pcmd = &io->cmd;
+				}
+
+				if (pio) {
+					*pio = io;
+				}
+
+				return rep;
+			}
+			found = TRUE;
+		}
+	}
+
+	if (!found) {
+		msg_info("unexpected tag: %ud", rep->v1.tag);
+	}
+
+	return NULL;
+}
+
+static void
+fuzzy_insert_result(struct fuzzy_client_session *session,
+					const struct rspamd_fuzzy_reply *rep,
+					struct rspamd_fuzzy_cmd *cmd,
+					struct fuzzy_cmd_io *io,
+					guint flag)
+{
+	const gchar *symbol;
+	struct fuzzy_mapping *map;
+	struct rspamd_task *task = session->task;
+	double weight;
+	double nval;
+	guchar buf[2048];
+	const gchar *type = "bin";
+	struct fuzzy_client_result *res;
+	gboolean is_fuzzy = FALSE;
+	gchar hexbuf[rspamd_cryptobox_HASHBYTES * 2 + 1];
+	/* Discriminate scores for small images */
+	static const guint short_image_limit = 32 * 1024;
+
+	/* Get mapping by flag */
+	if ((map =
+			 g_hash_table_lookup(session->rule->mappings,
+								 GINT_TO_POINTER(rep->v1.flag))) == NULL) {
+		/* Default symbol and default weight */
+		symbol = session->rule->symbol;
+		weight = session->rule->max_score;
+	}
+	else {
+		/* Get symbol and weight from map */
+		symbol = map->symbol;
+		weight = map->weight;
+	}
+
+	res = rspamd_mempool_alloc0(task->task_pool, sizeof(*res));
+	res->prob = rep->v1.prob;
+	res->symbol = symbol;
+	/*
+	 * Hash is assumed to be found if probability is more than 0.5
+	 * In that case `value` means number of matches
+	 * Otherwise `value` means error code
+	 */
+
+	nval = fuzzy_normalize(rep->v1.value, weight);
+
+	if (io) {
+		if ((io->flags & FUZZY_CMD_FLAG_IMAGE)) {
+			if (!io->part || io->part->parsed_data.len <= short_image_limit) {
+				nval *= rspamd_normalize_probability(rep->v1.prob, 0.5);
+			}
+
+			type = "img";
+			res->type = FUZZY_RESULT_IMG;
+		}
+		else {
+			/* Calc real probability */
+			nval *= sqrtf(rep->v1.prob);
+
+			if (cmd->shingles_count > 0) {
+				type = "txt";
+				res->type = FUZZY_RESULT_TXT;
+			}
+			else {
+				if (io->flags & FUZZY_CMD_FLAG_CONTENT) {
+					type = "content";
+					res->type = FUZZY_RESULT_CONTENT;
+				}
+				else {
+					res->type = FUZZY_RESULT_BIN;
+				}
+			}
+		}
+	}
+
+	res->score = nval;
+
+	if (memcmp(rep->digest, cmd->digest, sizeof(rep->digest)) != 0) {
+		is_fuzzy = TRUE;
+	}
+
+	if (map != NULL || !session->rule->skip_unknown) {
+		GList *fuzzy_var;
+		rspamd_fstring_t *hex_result;
+		gchar timebuf[64];
+		struct tm tm_split;
+
+		if (session->rule->skip_map) {
+			rspamd_encode_hex_buf(cmd->digest, sizeof(cmd->digest),
+								  hexbuf, sizeof(hexbuf) - 1);
+			hexbuf[sizeof(hexbuf) - 1] = '\0';
+			if (rspamd_match_hash_map(session->rule->skip_map, hexbuf,
+									  sizeof(hexbuf) - 1)) {
+				return;
+			}
+		}
+
+		rspamd_encode_hex_buf(rep->digest, sizeof(rep->digest),
+							  hexbuf, sizeof(hexbuf) - 1);
+		hexbuf[sizeof(hexbuf) - 1] = '\0';
+
+		rspamd_gmtime(rep->ts, &tm_split);
+		rspamd_snprintf(timebuf, sizeof(timebuf), "%02d.%02d.%4d %02d:%02d:%02d GMT",
+						tm_split.tm_mday,
+						tm_split.tm_mon + 1,
+						tm_split.tm_year + 1900,
+						tm_split.tm_hour, tm_split.tm_min, tm_split.tm_sec);
+
+		if (is_fuzzy) {
+			msg_notice_task(
+				"found fuzzy hash(%s) %s (%*xs requested) with weight: "
+				"%.2f, probability %.2f, in list: %s:%d%s; added on %s",
+				type,
+				hexbuf,
+				(gint) sizeof(cmd->digest), cmd->digest,
+				nval,
+				(gdouble) rep->v1.prob,
+				symbol,
+				rep->v1.flag,
+				map == NULL ? "(unknown)" : "",
+				timebuf);
+		}
+		else {
+			msg_notice_task(
+				"found exact fuzzy hash(%s) %s with weight: "
+				"%.2f, probability %.2f, in list: %s:%d%s; added on %s",
+				type,
+				hexbuf,
+				nval,
+				(gdouble) rep->v1.prob,
+				symbol,
+				rep->v1.flag,
+				map == NULL ? "(unknown)" : "",
+				timebuf);
+		}
+
+		rspamd_snprintf(buf,
+						sizeof(buf),
+						"%d:%*s:%.2f:%s",
+						rep->v1.flag,
+						(gint) MIN(rspamd_fuzzy_hash_len * 2, sizeof(rep->digest) * 2), hexbuf,
+						rep->v1.prob,
+						type);
+		res->option = rspamd_mempool_strdup(task->task_pool, buf);
+		g_ptr_array_add(session->results, res);
+
+		/* Store hex string in pool variable */
+		hex_result = rspamd_mempool_alloc(task->task_pool,
+										  sizeof(rspamd_fstring_t) + sizeof(hexbuf));
+		memcpy(hex_result->str, hexbuf, sizeof(hexbuf));
+		hex_result->len = sizeof(hexbuf) - 1;
+		hex_result->allocated = (gsize) -1;
+		fuzzy_var = rspamd_mempool_get_variable(task->task_pool,
+												RSPAMD_MEMPOOL_FUZZY_RESULT);
+
+		if (fuzzy_var == NULL) {
+			fuzzy_var = g_list_prepend(NULL, hex_result);
+			rspamd_mempool_set_variable(task->task_pool,
+										RSPAMD_MEMPOOL_FUZZY_RESULT, fuzzy_var,
+										(rspamd_mempool_destruct_t) g_list_free);
+		}
+		else {
+			/* Not very efficient, but we don't really use it intensively */
+			fuzzy_var = g_list_append(fuzzy_var, hex_result);
+		}
+	}
+}
+
+static gint
+fuzzy_check_try_read(struct fuzzy_client_session *session)
+{
+	struct rspamd_task *task;
+	const struct rspamd_fuzzy_reply *rep;
+	struct rspamd_fuzzy_cmd *cmd = NULL;
+	struct fuzzy_cmd_io *io = NULL;
+	gint r, ret;
+	guchar buf[2048], *p;
+
+	task = session->task;
+
+	if ((r = read(session->fd, buf, sizeof(buf) - 1)) == -1) {
+		if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR) {
+			return 0;
+		}
+		else {
+			return -1;
+		}
+	}
+	else {
+		p = buf;
+
+		ret = 0;
+
+		while ((rep = fuzzy_process_reply(&p, &r,
+										  session->commands, session->rule, &cmd, &io)) != NULL) {
+			if (rep->v1.prob > 0.5) {
+				if (cmd->cmd == FUZZY_CHECK) {
+					fuzzy_insert_result(session, rep, cmd, io, rep->v1.flag);
+				}
+				else if (cmd->cmd == FUZZY_STAT) {
+					/*
+					 * We store fuzzy stat in the following way:
+					 * 1) We store fuzzy hashes as a hash of rspamd_fuzzy_stat_entry
+					 * 2) We store the resulting hash table inside pool variable `fuzzy_stat`
+					 */
+					struct rspamd_fuzzy_stat_entry *pval;
+					GHashTable *stats_hash;
+
+					stats_hash = (GHashTable *) rspamd_mempool_get_variable(task->task_pool,
+																			RSPAMD_MEMPOOL_FUZZY_STAT);
+
+					if (stats_hash == NULL) {
+						stats_hash = g_hash_table_new(rspamd_str_hash, rspamd_str_equal);
+						rspamd_mempool_set_variable(task->task_pool, RSPAMD_MEMPOOL_FUZZY_STAT,
+													stats_hash,
+													(rspamd_mempool_destruct_t) g_hash_table_destroy);
+					}
+
+					pval = g_hash_table_lookup(stats_hash, session->rule->name);
+
+					if (pval == NULL) {
+						pval = rspamd_mempool_alloc(task->task_pool,
+													sizeof(*pval));
+						pval->name = rspamd_mempool_strdup(task->task_pool,
+														   session->rule->name);
+						/* Safe, as pval->name is owned by the pool */
+						g_hash_table_insert(stats_hash, (char *) pval->name, pval);
+					}
+
+					pval->fuzzy_cnt = (((guint64) rep->v1.value) << 32) + rep->v1.flag;
+				}
+			}
+			else if (rep->v1.value == 403) {
+				rspamd_task_insert_result(task, "FUZZY_BLOCKED", 0.0,
+										  session->rule->name);
+			}
+			else if (rep->v1.value == 401) {
+				if (cmd->cmd != FUZZY_CHECK) {
+					msg_info_task(
+						"fuzzy check error for %d: skipped by server",
+						rep->v1.flag);
+				}
+			}
+			else if (rep->v1.value != 0) {
+				msg_info_task(
+					"fuzzy check error for %d: unknown error (%d)",
+					rep->v1.flag,
+					rep->v1.value);
+			}
+
+			ret = 1;
+		}
+	}
+
+	return ret;
+}
+
+static void
+fuzzy_insert_metric_results(struct rspamd_task *task, struct fuzzy_rule *rule,
+							GPtrArray *results)
+{
+	struct fuzzy_client_result *res;
+	guint i;
+	gboolean seen_text_hash = FALSE,
+			 seen_img_hash = FALSE,
+			 seen_text_part = FALSE,
+			 seen_long_text = FALSE;
+	gdouble prob_txt = 0.0, mult;
+	struct rspamd_mime_text_part *tp;
+
+	/* About 5 words */
+	static const unsigned int text_length_cutoff = 25;
+
+	PTR_ARRAY_FOREACH(results, i, res)
+	{
+		if (res->type == FUZZY_RESULT_TXT) {
+			seen_text_hash = TRUE;
+			prob_txt = MAX(prob_txt, res->prob);
+		}
+		else if (res->type == FUZZY_RESULT_IMG) {
+			seen_img_hash = TRUE;
+		}
+	}
+
+	if (task->message) {
+		PTR_ARRAY_FOREACH(MESSAGE_FIELD(task, text_parts), i, tp)
+		{
+			if (!IS_TEXT_PART_EMPTY(tp) && tp->utf_words != NULL && tp->utf_words->len > 0) {
+				seen_text_part = TRUE;
+
+				if (tp->utf_stripped_text.magic == UTEXT_MAGIC) {
+					if (utext_isLengthExpensive(&tp->utf_stripped_text)) {
+						seen_long_text =
+							utext_nativeLength(&tp->utf_stripped_text) >
+							text_length_cutoff;
+					}
+					else {
+						/* Cannot directly calculate length */
+						seen_long_text =
+							(tp->utf_stripped_content->len / 2) >
+							text_length_cutoff;
+					}
+				}
+			}
+		}
+	}
+
+	PTR_ARRAY_FOREACH(results, i, res)
+	{
+		mult = 1.0;
+
+		if (res->type == FUZZY_RESULT_IMG) {
+			if (!seen_text_hash) {
+				if (seen_long_text) {
+					mult *= 0.25;
+				}
+				else if (seen_text_part) {
+					/* We have some short text + image */
+					mult *= 0.9;
+				}
+				/* Otherwise apply full score */
+			}
+			else if (prob_txt < 0.75) {
+				/* Penalize sole image without matching text */
+				if (prob_txt > 0.5) {
+					mult *= prob_txt;
+				}
+				else {
+					mult *= 0.5; /* cutoff */
+				}
+			}
+		}
+		else if (res->type == FUZZY_RESULT_TXT) {
+			if (seen_img_hash) {
+				/* Slightly increase score */
+				mult = 1.1;
+			}
+		}
+
+		gdouble weight = res->score * mult;
+
+		if (!isnan(rule->weight_threshold)) {
+			if (weight >= rule->weight_threshold) {
+				rspamd_task_insert_result_single(task, res->symbol,
+												 weight, res->option);
+			}
+			else {
+				msg_info_task("%s is not added: weight=%.4f below threshold",
+							  res->symbol, weight);
+			}
+		}
+		else {
+			rspamd_task_insert_result_single(task, res->symbol,
+											 weight, res->option);
+		}
+	}
+}
+
+static gboolean
+fuzzy_check_session_is_completed(struct fuzzy_client_session *session)
+{
+	struct fuzzy_cmd_io *io;
+	guint nreplied = 0, i;
+
+	rspamd_upstream_ok(session->server);
+
+	for (i = 0; i < session->commands->len; i++) {
+		io = g_ptr_array_index(session->commands, i);
+
+		if (io->flags & FUZZY_CMD_FLAG_REPLIED) {
+			nreplied++;
+		}
+	}
+
+	if (nreplied == session->commands->len) {
+		fuzzy_insert_metric_results(session->task, session->rule, session->results);
+
+		if (session->item) {
+			rspamd_symcache_item_async_dec_check(session->task, session->item, M);
+		}
+
+		rspamd_session_remove_event(session->task->s, fuzzy_io_fin, session);
+
+		return TRUE;
+	}
+
+	return FALSE;
+}
+
+/* Fuzzy check timeout callback */
+static void
+fuzzy_check_timer_callback(gint fd, short what, void *arg)
+{
+	struct fuzzy_client_session *session = arg;
+	struct rspamd_task *task;
+
+	task = session->task;
+
+	/* We might be here because of other checks being slow */
+	if (fuzzy_check_try_read(session) > 0) {
+		if (fuzzy_check_session_is_completed(session)) {
+			return;
+		}
+	}
+
+	if (session->retransmits >= session->rule->retransmits) {
+		msg_err_task("got IO timeout with server %s(%s), after %d/%d retransmits",
+					 rspamd_upstream_name(session->server),
+					 rspamd_inet_address_to_string_pretty(
+						 rspamd_upstream_addr_cur(session->server)),
+					 session->retransmits,
+					 session->rule->retransmits);
+		rspamd_upstream_fail(session->server, TRUE, "timeout");
+
+		if (session->item) {
+			rspamd_symcache_item_async_dec_check(session->task, session->item, M);
+		}
+		rspamd_session_remove_event(session->task->s, fuzzy_io_fin, session);
+	}
+	else {
+		/* Plan write event */
+		rspamd_ev_watcher_reschedule(session->event_loop,
+									 &session->ev, EV_READ | EV_WRITE);
+		session->retransmits++;
+	}
+}
+
+/* Fuzzy check callback */
+static void
+fuzzy_check_io_callback(gint fd, short what, void *arg)
+{
+	struct fuzzy_client_session *session = arg;
+	struct rspamd_task *task;
+	gint r;
+
+	enum {
+		return_error = 0,
+		return_want_more,
+		return_finished
+	} ret = return_error;
+
+	task = session->task;
+
+	if ((what & EV_READ) || session->state == 1) {
+		/* Try to read reply */
+		r = fuzzy_check_try_read(session);
+
+		switch (r) {
+		case 0:
+			if (what & EV_READ) {
+				ret = return_want_more;
+			}
+			else {
+				if (what & EV_WRITE) {
+					/* Retransmit attempt */
+					if (!fuzzy_cmd_vector_to_wire(fd, session->commands)) {
+						ret = return_error;
+					}
+					else {
+						session->state = 1;
+						ret = return_want_more;
+					}
+				}
+				else {
+					/* It is actually time out */
+					fuzzy_check_timer_callback(fd, what, arg);
+					return;
+				}
+			}
+			break;
+		case 1:
+			ret = return_finished;
+			break;
+		default:
+			ret = return_error;
+			break;
+		}
+	}
+	else if (what & EV_WRITE) {
+		if (!fuzzy_cmd_vector_to_wire(fd, session->commands)) {
+			ret = return_error;
+		}
+		else {
+			session->state = 1;
+			ret = return_want_more;
+		}
+	}
+	else {
+		fuzzy_check_timer_callback(fd, what, arg);
+		return;
+	}
+
+	if (ret == return_want_more) {
+		/* Processed write, switch to reading */
+		rspamd_ev_watcher_reschedule(session->event_loop,
+									 &session->ev, EV_READ);
+	}
+	else if (ret == return_error) {
+		/* Error state */
+		msg_err_task("got error on IO with server %s(%s), on %s, %d, %s",
+					 rspamd_upstream_name(session->server),
+					 rspamd_inet_address_to_string_pretty(
+						 rspamd_upstream_addr_cur(session->server)),
+					 session->state == 1 ? "read" : "write",
+					 errno,
+					 strerror(errno));
+		rspamd_upstream_fail(session->server, TRUE, strerror(errno));
+
+		if (session->item) {
+			rspamd_symcache_item_async_dec_check(session->task, session->item, M);
+		}
+
+		rspamd_session_remove_event(session->task->s, fuzzy_io_fin, session);
+	}
+	else {
+		/* Read something from network */
+		if (!fuzzy_check_session_is_completed(session)) {
+			/* Need to read more */
+			rspamd_ev_watcher_reschedule(session->event_loop,
+										 &session->ev, EV_READ);
+		}
+	}
+}
+
+
+static void
+fuzzy_controller_lua_fin(void *ud)
+{
+	struct fuzzy_learn_session *session = ud;
+
+	(*session->saved)--;
+
+	rspamd_ev_watcher_stop(session->event_loop, &session->ev);
+	close(session->fd);
+}
+
+/* Controller IO */
+
+static void
+fuzzy_controller_timer_callback(gint fd, short what, void *arg)
+{
+	struct fuzzy_learn_session *session = arg;
+	struct rspamd_task *task;
+
+	task = session->task;
+
+	if (session->retransmits >= session->rule->retransmits) {
+		rspamd_upstream_fail(session->server, TRUE, "timeout");
+		msg_err_task_check("got IO timeout with server %s(%s), "
+						   "after %d/%d retransmits",
+						   rspamd_upstream_name(session->server),
+						   rspamd_inet_address_to_string_pretty(
+							   rspamd_upstream_addr_cur(session->server)),
+						   session->retransmits,
+						   session->rule->retransmits);
+
+		if (session->session) {
+			rspamd_session_remove_event(session->session, fuzzy_controller_lua_fin,
+										session);
+		}
+		else {
+			if (session->http_entry) {
+				rspamd_controller_send_error(session->http_entry,
+											 500, "IO timeout with fuzzy storage");
+			}
+
+			if (*session->saved > 0) {
+				(*session->saved)--;
+				if (*session->saved == 0) {
+					if (session->http_entry) {
+						rspamd_task_free(session->task);
+					}
+
+					session->task = NULL;
+				}
+			}
+
+			if (session->http_entry) {
+				rspamd_http_connection_unref(session->http_entry->conn);
+			}
+
+			rspamd_ev_watcher_stop(session->event_loop,
+								   &session->ev);
+			close(session->fd);
+		}
+	}
+	else {
+		/* Plan write event */
+		rspamd_ev_watcher_reschedule(session->event_loop,
+									 &session->ev, EV_READ | EV_WRITE);
+		session->retransmits++;
+	}
+}
+
+static void
+fuzzy_controller_io_callback(gint fd, short what, void *arg)
+{
+	struct fuzzy_learn_session *session = arg;
+	const struct rspamd_fuzzy_reply *rep;
+	struct fuzzy_mapping *map;
+	struct rspamd_task *task;
+	guchar buf[2048], *p;
+	struct fuzzy_cmd_io *io;
+	struct rspamd_fuzzy_cmd *cmd = NULL;
+	const gchar *symbol, *ftype;
+	gint r;
+	enum {
+		return_error = 0,
+		return_want_more,
+		return_finished
+	} ret = return_want_more;
+	guint i, nreplied;
+	const gchar *op = "process";
+
+	task = session->task;
+
+	if (what & EV_READ) {
+		if ((r = read(fd, buf, sizeof(buf) - 1)) == -1) {
+			if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR) {
+				rspamd_ev_watcher_reschedule(session->event_loop,
+											 &session->ev, EV_READ);
+				return;
+			}
+
+			msg_info_task("cannot process fuzzy hash for message: %s",
+						  strerror(errno));
+			session->err.error_message = "read socket error";
+			session->err.error_code = errno;
+
+			ret = return_error;
+		}
+		else {
+			p = buf;
+			ret = return_want_more;
+
+			while ((rep = fuzzy_process_reply(&p, &r,
+											  session->commands, session->rule, &cmd, &io)) != NULL) {
+				if ((map =
+						 g_hash_table_lookup(session->rule->mappings,
+											 GINT_TO_POINTER(rep->v1.flag))) == NULL) {
+					/* Default symbol and default weight */
+					symbol = session->rule->symbol;
+				}
+				else {
+					/* Get symbol and weight from map */
+					symbol = map->symbol;
+				}
+
+				ftype = "bin";
+
+				if (io) {
+					if ((io->flags & FUZZY_CMD_FLAG_IMAGE)) {
+						ftype = "img";
+					}
+					else if (io->flags & FUZZY_CMD_FLAG_CONTENT) {
+						ftype = "content";
+					}
+					else if (cmd->shingles_count > 0) {
+						ftype = "txt";
+					}
+
+					if (io->cmd.cmd == FUZZY_WRITE) {
+						op = "added";
+					}
+					else if (io->cmd.cmd == FUZZY_DEL) {
+						op = "deleted";
+					}
+				}
+
+				if (rep->v1.prob > 0.5) {
+					msg_info_task("%s fuzzy hash (%s) %*xs, list: %s:%d for "
+								  "message <%s>",
+								  op,
+								  ftype,
+								  (gint) sizeof(rep->digest), rep->digest,
+								  symbol,
+								  rep->v1.flag,
+								  MESSAGE_FIELD_CHECK(session->task, message_id));
+				}
+				else {
+					if (rep->v1.value == 401) {
+						msg_info_task(
+							"fuzzy hash (%s) for message cannot be %s"
+							"<%s>, %*xs, "
+							"list %s:%d, skipped by server",
+							ftype,
+							op,
+							MESSAGE_FIELD_CHECK(session->task, message_id),
+							(gint) sizeof(rep->digest), rep->digest,
+							symbol,
+							rep->v1.flag);
+
+						session->err.error_message = "fuzzy hash is skipped";
+						session->err.error_code = rep->v1.value;
+					}
+					else {
+						msg_info_task(
+							"fuzzy hash (%s) for message cannot be %s"
+							"<%s>, %*xs, "
+							"list %s:%d, error: %d",
+							ftype,
+							op,
+							MESSAGE_FIELD_CHECK(session->task, message_id),
+							(gint) sizeof(rep->digest), rep->digest,
+							symbol,
+							rep->v1.flag,
+							rep->v1.value);
+
+						session->err.error_message = "process fuzzy error";
+						session->err.error_code = rep->v1.value;
+					}
+
+					ret = return_finished;
+				}
+			}
+
+			nreplied = 0;
+
+			for (i = 0; i < session->commands->len; i++) {
+				io = g_ptr_array_index(session->commands, i);
+
+				if (io->flags & FUZZY_CMD_FLAG_REPLIED) {
+					nreplied++;
+				}
+			}
+
+			if (nreplied == session->commands->len) {
+				ret = return_finished;
+			}
+		}
+	}
+	else if (what & EV_WRITE) {
+		/* Send commands to storage */
+		if (!fuzzy_cmd_vector_to_wire(fd, session->commands)) {
+			session->err.error_message = "write socket error";
+			session->err.error_code = errno;
+			ret = return_error;
+		}
+	}
+	else {
+		fuzzy_controller_timer_callback(fd, what, arg);
+
+		return;
+	}
+
+	if (ret == return_want_more) {
+		rspamd_ev_watcher_reschedule(session->event_loop,
+									 &session->ev, EV_READ);
+
+		return;
+	}
+	else if (ret == return_error) {
+		msg_err_task("got error in IO with server %s(%s), %d, %s",
+					 rspamd_upstream_name(session->server),
+					 rspamd_inet_address_to_string_pretty(
+						 rspamd_upstream_addr_cur(session->server)),
+					 errno, strerror(errno));
+		rspamd_upstream_fail(session->server, FALSE, strerror(errno));
+	}
+
+	/*
+	 * XXX: actually, we check merely a single reply, which is not correct...
+	 * XXX: when we send a command, we do not check if *all* commands have been
+	 * written
+	 * XXX: please, please, change this code some day
+	 */
+
+	if (session->session == NULL) {
+		(*session->saved)--;
+
+		if (session->http_entry) {
+			rspamd_http_connection_unref(session->http_entry->conn);
+		}
+
+		rspamd_ev_watcher_stop(session->event_loop, &session->ev);
+		close(session->fd);
+
+		if (*session->saved == 0) {
+			goto cleanup;
+		}
+	}
+	else {
+		/* Lua handler */
+		rspamd_session_remove_event(session->session, fuzzy_controller_lua_fin, session);
+	}
+
+	return;
+
+cleanup:
+	/*
+	 * When we send learn commands to fuzzy storages, this code is executed
+	 * *once* when we have queried all storages. We also don't know which
+	 * storage has been failed.
+	 *
+	 * Therefore, we cleanup sessions earlier and actually this code is wrong.
+	 */
+
+	if (session->err.error_code != 0) {
+		if (session->http_entry) {
+			rspamd_controller_send_error(session->http_entry,
+										 session->err.error_code, session->err.error_message);
+		}
+	}
+	else {
+		rspamd_upstream_ok(session->server);
+
+		if (session->http_entry) {
+			ucl_object_t *reply, *hashes;
+			gchar hexbuf[rspamd_cryptobox_HASHBYTES * 2 + 1];
+
+			reply = ucl_object_typed_new(UCL_OBJECT);
+
+			ucl_object_insert_key(reply, ucl_object_frombool(true),
+								  "success", 0, false);
+			hashes = ucl_object_typed_new(UCL_ARRAY);
+
+			for (i = 0; i < session->commands->len; i++) {
+				io = g_ptr_array_index(session->commands, i);
+
+				rspamd_snprintf(hexbuf, sizeof(hexbuf), "%*xs",
+								(gint) sizeof(io->cmd.digest), io->cmd.digest);
+				ucl_array_append(hashes, ucl_object_fromstring(hexbuf));
+			}
+
+			ucl_object_insert_key(reply, hashes, "hashes", 0, false);
+			rspamd_controller_send_ucl(session->http_entry, reply);
+			ucl_object_unref(reply);
+		}
+	}
+
+	if (session->task != NULL) {
+		if (session->http_entry) {
+			rspamd_task_free(session->task);
+		}
+
+		session->task = NULL;
+	}
+}
+
+static GPtrArray *
+fuzzy_generate_commands(struct rspamd_task *task, struct fuzzy_rule *rule,
+						gint c, gint flag, guint32 value, guint flags)
+{
+	struct rspamd_mime_text_part *part;
+	struct rspamd_mime_part *mime_part;
+	struct rspamd_image *image;
+	struct fuzzy_cmd_io *io, *cur;
+	guint i, j;
+	GPtrArray *res = NULL;
+	gboolean check_part, fuzzy_check;
+
+	if (c == FUZZY_STAT) {
+		res = g_ptr_array_sized_new(1);
+
+		io = fuzzy_cmd_stat(rule, c, flag, value, task->task_pool);
+		if (io) {
+			g_ptr_array_add(res, io);
+		}
+
+		goto end;
+	}
+	else if (c == FUZZY_PING) {
+		res = g_ptr_array_sized_new(1);
+
+		io = fuzzy_cmd_ping(rule, task->task_pool);
+		if (io) {
+			g_ptr_array_add(res, io);
+		}
+
+		goto end;
+	}
+
+	if (task->message == NULL) {
+		goto end;
+	}
+
+	res = g_ptr_array_sized_new(MESSAGE_FIELD(task, parts)->len + 1);
+
+	PTR_ARRAY_FOREACH(MESSAGE_FIELD(task, parts), i, mime_part)
+	{
+		check_part = FALSE;
+		fuzzy_check = FALSE;
+
+		if (fuzzy_rule_check_mimepart(task, rule, mime_part, &check_part,
+									  &fuzzy_check)) {
+			io = NULL;
+
+			if (check_part) {
+				if (mime_part->part_type == RSPAMD_MIME_PART_TEXT &&
+					!(flags & FUZZY_CHECK_FLAG_NOTEXT)) {
+					part = mime_part->specific.txt;
+
+					io = fuzzy_cmd_from_text_part(task, rule,
+												  c,
+												  flag,
+												  value,
+												  !fuzzy_check,
+												  part,
+												  mime_part);
+				}
+				else if (mime_part->part_type == RSPAMD_MIME_PART_IMAGE &&
+						 !(flags & FUZZY_CHECK_FLAG_NOIMAGES)) {
+					image = mime_part->specific.img;
+
+					io = fuzzy_cmd_from_data_part(rule, c, flag, value,
+												  task,
+												  image->parent->digest,
+												  mime_part);
+					io->flags |= FUZZY_CMD_FLAG_IMAGE;
+				}
+				else if (mime_part->part_type == RSPAMD_MIME_PART_CUSTOM_LUA) {
+					const struct rspamd_lua_specific_part *lua_spec;
+
+					lua_spec = &mime_part->specific.lua_specific;
+
+					if (lua_spec->type == RSPAMD_LUA_PART_TABLE) {
+						lua_State *L = (lua_State *) task->cfg->lua_state;
+						gint old_top;
+
+						old_top = lua_gettop(L);
+						/* Push table */
+						lua_rawgeti(L, LUA_REGISTRYINDEX, lua_spec->cbref);
+						lua_pushstring(L, "fuzzy_hashes");
+						lua_gettable(L, -2);
+
+						if (lua_type(L, -1) == LUA_TTABLE) {
+							gint tbl_pos = lua_gettop(L);
+
+							for (lua_pushnil(L); lua_next(L, tbl_pos);
+								 lua_pop(L, 1)) {
+								const gchar *h = NULL;
+								gsize hlen = 0;
+
+								if (lua_isstring(L, -1)) {
+									h = lua_tolstring(L, -1, &hlen);
+								}
+								else if (lua_type(L, -1) == LUA_TUSERDATA) {
+									struct rspamd_lua_text *t;
+
+									t = lua_check_text(L, -1);
+
+									if (t) {
+										h = t->start;
+										hlen = t->len;
+									}
+								}
+
+								if (hlen == rspamd_cryptobox_HASHBYTES) {
+									io = fuzzy_cmd_from_data_part(rule, c,
+																  flag, value,
+																  task,
+																  (guchar *) h,
+																  mime_part);
+
+									if (io) {
+										io->flags |= FUZZY_CMD_FLAG_CONTENT;
+										g_ptr_array_add(res, io);
+									}
+								}
+							}
+						}
+
+						lua_settop(L, old_top);
+
+						/*
+						 * Add part itself as well
+						 */
+						io = fuzzy_cmd_from_data_part(rule, c,
+													  flag, value,
+													  task,
+													  mime_part->digest,
+													  mime_part);
+					}
+				}
+				else {
+					io = fuzzy_cmd_from_data_part(rule, c, flag, value,
+												  task,
+												  mime_part->digest, mime_part);
+				}
+
+				if (io) {
+					gboolean skip_existing = FALSE;
+
+					PTR_ARRAY_FOREACH(res, j, cur)
+					{
+						if (memcmp(cur->cmd.digest, io->cmd.digest,
+								   sizeof(io->cmd.digest)) == 0) {
+							skip_existing = TRUE;
+							break;
+						}
+					}
+
+					if (!skip_existing) {
+						g_ptr_array_add(res, io);
+					}
+				}
+			}
+		}
+	}
+
+end:
+	if (res && res->len == 0) {
+		g_ptr_array_free(res, TRUE);
+
+		return NULL;
+	}
+
+	return res;
+}
+
+
+static inline void
+register_fuzzy_client_call(struct rspamd_task *task,
+						   struct fuzzy_rule *rule,
+						   GPtrArray *commands)
+{
+	struct fuzzy_client_session *session;
+	struct upstream *selected;
+	rspamd_inet_addr_t *addr;
+	gint sock;
+
+	if (!rspamd_session_blocked(task->s)) {
+		/* Get upstream */
+		selected = rspamd_upstream_get(rule->servers, RSPAMD_UPSTREAM_ROUND_ROBIN,
+									   NULL, 0);
+		if (selected) {
+			addr = rspamd_upstream_addr_next(selected);
+			if ((sock = rspamd_inet_address_connect(addr, SOCK_DGRAM, TRUE)) == -1) {
+				msg_warn_task("cannot connect to %s(%s), %d, %s",
+							  rspamd_upstream_name(selected),
+							  rspamd_inet_address_to_string_pretty(addr),
+							  errno,
+							  strerror(errno));
+				rspamd_upstream_fail(selected, TRUE, strerror(errno));
+				g_ptr_array_free(commands, TRUE);
+			}
+			else {
+				/* Create session for a socket */
+				session =
+					rspamd_mempool_alloc0(task->task_pool,
+										  sizeof(struct fuzzy_client_session));
+				session->state = 0;
+				session->commands = commands;
+				session->task = task;
+				session->fd = sock;
+				session->server = selected;
+				session->rule = rule;
+				session->results = g_ptr_array_sized_new(32);
+				session->event_loop = task->event_loop;
+
+				rspamd_ev_watcher_init(&session->ev,
+									   sock,
+									   EV_WRITE,
+									   fuzzy_check_io_callback,
+									   session);
+				rspamd_ev_watcher_start(session->event_loop, &session->ev,
+										rule->io_timeout);
+
+				rspamd_session_add_event(task->s, fuzzy_io_fin, session, M);
+				session->item = rspamd_symcache_get_cur_item(task);
+
+				if (session->item) {
+					rspamd_symcache_item_async_inc(task, session->item, M);
+				}
+			}
+		}
+	}
+}
+
+/* This callback is called when we check message in fuzzy hashes storage */
+static void
+fuzzy_symbol_callback(struct rspamd_task *task,
+					  struct rspamd_symcache_dynamic_item *item,
+					  void *unused)
+{
+	struct fuzzy_rule *rule;
+	guint i;
+	GPtrArray *commands;
+	struct fuzzy_ctx *fuzzy_module_ctx = fuzzy_get_context(task->cfg);
+
+	if (!fuzzy_module_ctx->enabled) {
+		rspamd_symcache_finalize_item(task, item);
+
+		return;
+	}
+
+	/* Check whitelist */
+	if (fuzzy_module_ctx->whitelist) {
+		if (rspamd_match_radix_map_addr(fuzzy_module_ctx->whitelist,
+										task->from_addr) != NULL) {
+			msg_info_task("<%s>, address %s is whitelisted, skip fuzzy check",
+						  MESSAGE_FIELD(task, message_id),
+						  rspamd_inet_address_to_string(task->from_addr));
+			rspamd_symcache_finalize_item(task, item);
+
+			return;
+		}
+	}
+
+	rspamd_symcache_item_async_inc(task, item, M);
+
+	PTR_ARRAY_FOREACH(fuzzy_module_ctx->fuzzy_rules, i, rule)
+	{
+		commands = fuzzy_generate_commands(task, rule, FUZZY_CHECK, 0, 0, 0);
+
+		if (commands != NULL) {
+			register_fuzzy_client_call(task, rule, commands);
+		}
+	}
+
+	rspamd_symcache_item_async_dec_check(task, item, M);
+}
+
+void fuzzy_stat_command(struct rspamd_task *task)
+{
+	struct fuzzy_rule *rule;
+	guint i;
+	GPtrArray *commands;
+	struct fuzzy_ctx *fuzzy_module_ctx = fuzzy_get_context(task->cfg);
+
+	if (!fuzzy_module_ctx->enabled) {
+		return;
+	}
+
+	PTR_ARRAY_FOREACH(fuzzy_module_ctx->fuzzy_rules, i, rule)
+	{
+		commands = fuzzy_generate_commands(task, rule, FUZZY_STAT, 0, 0, 0);
+		if (commands != NULL) {
+			register_fuzzy_client_call(task, rule, commands);
+		}
+	}
+}
+
+static inline gint
+register_fuzzy_controller_call(struct rspamd_http_connection_entry *entry,
+							   struct fuzzy_rule *rule,
+							   struct rspamd_task *task,
+							   GPtrArray *commands,
+							   gint *saved)
+{
+	struct fuzzy_learn_session *s;
+	struct upstream *selected;
+	rspamd_inet_addr_t *addr;
+	struct rspamd_controller_session *session = entry->ud;
+	gint sock;
+	gint ret = -1;
+
+	/* Get upstream */
+
+	while ((selected = rspamd_upstream_get_forced(rule->servers,
+												  RSPAMD_UPSTREAM_SEQUENTIAL, NULL, 0))) {
+		/* Create UDP socket */
+		addr = rspamd_upstream_addr_next(selected);
+
+		if ((sock = rspamd_inet_address_connect(addr,
+												SOCK_DGRAM, TRUE)) == -1) {
+			msg_warn_task("cannot connect to fuzzy storage %s (%s rule): %s",
+						  rspamd_inet_address_to_string_pretty(addr),
+						  rule->name,
+						  strerror(errno));
+			rspamd_upstream_fail(selected, TRUE, strerror(errno));
+		}
+		else {
+			s =
+				rspamd_mempool_alloc0(session->pool,
+									  sizeof(struct fuzzy_learn_session));
+
+			s->task = task;
+			s->commands = commands;
+			s->http_entry = entry;
+			s->server = selected;
+			s->saved = saved;
+			s->fd = sock;
+			s->rule = rule;
+			s->event_loop = task->event_loop;
+			/* We ref connection to avoid freeing before we process fuzzy rule */
+			rspamd_http_connection_ref(entry->conn);
+
+			rspamd_ev_watcher_init(&s->ev,
+								   sock,
+								   EV_WRITE,
+								   fuzzy_controller_io_callback,
+								   s);
+			rspamd_ev_watcher_start(s->event_loop, &s->ev, rule->io_timeout);
+
+			(*saved)++;
+			ret = 1;
+		}
+	}
+
+	return ret;
+}
+
+static void
+fuzzy_process_handler(struct rspamd_http_connection_entry *conn_ent,
+					  struct rspamd_http_message *msg, gint cmd, gint value, gint flag,
+					  struct fuzzy_ctx *ctx, gboolean is_hash, guint flags)
+{
+	struct fuzzy_rule *rule;
+	struct rspamd_controller_session *session = conn_ent->ud;
+	struct rspamd_task *task, **ptask;
+	gboolean processed = FALSE, skip = FALSE;
+	gint res = 0;
+	guint i;
+	GPtrArray *commands;
+	lua_State *L;
+	gint r, *saved, rules = 0, err_idx;
+	struct fuzzy_ctx *fuzzy_module_ctx;
+
+	/* Prepare task */
+	task = rspamd_task_new(session->wrk, session->cfg, NULL,
+						   session->lang_det, conn_ent->rt->event_loop, FALSE);
+	task->cfg = ctx->cfg;
+	saved = rspamd_mempool_alloc0(session->pool, sizeof(gint));
+	fuzzy_module_ctx = fuzzy_get_context(ctx->cfg);
+
+	if (!is_hash) {
+		/* Allocate message from string */
+		/* XXX: what about encrypted messages ? */
+		task->msg.begin = msg->body_buf.begin;
+		task->msg.len = msg->body_buf.len;
+
+		r = rspamd_message_parse(task);
+
+		if (r == -1) {
+			msg_warn_task("<%s>: cannot process message for fuzzy",
+						  MESSAGE_FIELD(task, message_id));
+			rspamd_task_free(task);
+			rspamd_controller_send_error(conn_ent, 400,
+										 "Message processing error");
+
+			return;
+		}
+
+		rspamd_message_process(task);
+	}
+
+	PTR_ARRAY_FOREACH(fuzzy_module_ctx->fuzzy_rules, i, rule)
+	{
+		if (rule->read_only) {
+			continue;
+		}
+
+		/* Check for flag */
+		if (g_hash_table_lookup(rule->mappings,
+								GINT_TO_POINTER(flag)) == NULL) {
+			msg_info_task("skip rule %s as it has no flag %d defined"
+						  " false",
+						  rule->name, flag);
+			continue;
+		}
+
+		/* Check learn condition */
+		if (rule->learn_condition_cb != -1) {
+			skip = FALSE;
+			L = session->cfg->lua_state;
+			lua_pushcfunction(L, &rspamd_lua_traceback);
+			err_idx = lua_gettop(L);
+
+			lua_rawgeti(L, LUA_REGISTRYINDEX, rule->learn_condition_cb);
+			ptask = lua_newuserdata(L, sizeof(struct rspamd_task *));
+			*ptask = task;
+			rspamd_lua_setclass(L, "rspamd{task}", -1);
+
+			if (lua_pcall(L, 1, LUA_MULTRET, err_idx) != 0) {
+				msg_err_task("call to fuzzy learn condition failed: %s",
+							 lua_tostring(L, -1));
+			}
+			else {
+				if (lua_gettop(L) > err_idx + 1) {
+					/* 2 return values */
+					skip = !(lua_toboolean(L, err_idx + 1));
+
+					if (lua_isnumber(L, err_idx + 2)) {
+						msg_info_task("learn condition changed flag from %d to "
+									  "%d",
+									  flag,
+									  (gint) lua_tonumber(L, err_idx + 2));
+						flag = lua_tonumber(L, err_idx + 2);
+					}
+				}
+				else {
+					if (lua_isboolean(L, err_idx + 1)) {
+						skip = !(lua_toboolean(L, err_idx + 1));
+					}
+					else {
+						msg_warn_task("set skip for rule %s as its condition "
+									  "callback returned"
+									  " a valid boolean",
+									  rule->name);
+						skip = TRUE;
+					}
+				}
+			}
+
+			/* Result + error function */
+			lua_settop(L, err_idx - 1);
+
+			if (skip) {
+				msg_info_task("skip rule %s by condition callback",
+							  rule->name);
+				continue;
+			}
+		}
+
+		rules++;
+
+		res = 0;
+
+		if (is_hash) {
+			GPtrArray *args;
+			const rspamd_ftok_t *arg;
+			guint j;
+
+			args = rspamd_http_message_find_header_multiple(msg, "Hash");
+
+			if (args) {
+				struct fuzzy_cmd_io *io;
+				commands = g_ptr_array_sized_new(args->len);
+
+				for (j = 0; j < args->len; j++) {
+					arg = g_ptr_array_index(args, j);
+					io = fuzzy_cmd_hash(rule, cmd, arg, flag, value,
+										task->task_pool);
+
+					if (io) {
+						g_ptr_array_add(commands, io);
+					}
+				}
+
+				res = register_fuzzy_controller_call(conn_ent,
+													 rule,
+													 task,
+													 commands,
+													 saved);
+				rspamd_mempool_add_destructor(task->task_pool,
+											  rspamd_ptr_array_free_hard, commands);
+				g_ptr_array_free(args, TRUE);
+			}
+			else {
+				rspamd_controller_send_error(conn_ent, 400,
+											 "No hash defined");
+				rspamd_task_free(task);
+				return;
+			}
+		}
+		else {
+			commands = fuzzy_generate_commands(task, rule, cmd, flag, value,
+											   flags);
+			if (commands != NULL) {
+				res = register_fuzzy_controller_call(conn_ent,
+													 rule,
+													 task,
+													 commands,
+													 saved);
+				rspamd_mempool_add_destructor(task->task_pool,
+											  rspamd_ptr_array_free_hard, commands);
+			}
+		}
+
+		if (res > 0) {
+			processed = TRUE;
+		}
+	}
+
+	if (res == -1) {
+		if (!processed) {
+			msg_warn_task("cannot send fuzzy request: %s",
+						  strerror(errno));
+			rspamd_controller_send_error(conn_ent, 400, "Message sending error");
+			rspamd_task_free(task);
+
+			return;
+		}
+		else {
+			/* Some rules failed and some rules are OK */
+			msg_warn_task("some rules are not processed, but we still sent this request");
+		}
+	}
+	else if (!processed) {
+		if (rules) {
+			msg_warn_task("no content to generate fuzzy");
+			rspamd_controller_send_error(conn_ent, 404,
+										 "No content to generate fuzzy for flag %d", flag);
+		}
+		else {
+			if (skip) {
+				rspamd_controller_send_error(conn_ent, 403,
+											 "Message is conditionally skipped for flag %d", flag);
+			}
+			else {
+				msg_warn_task("no fuzzy rules found for flag %d", flag);
+				rspamd_controller_send_error(conn_ent, 404,
+											 "No fuzzy rules matched for flag %d", flag);
+			}
+		}
+		rspamd_task_free(task);
+	}
+}
+
+static int
+fuzzy_controller_handler(struct rspamd_http_connection_entry *conn_ent,
+						 struct rspamd_http_message *msg, struct module_ctx *ctx, gint cmd,
+						 gboolean is_hash)
+{
+	const rspamd_ftok_t *arg;
+	glong value = 1, flag = 0, send_flags = 0;
+	struct fuzzy_ctx *fuzzy_module_ctx = (struct fuzzy_ctx *) ctx;
+
+	if (!fuzzy_module_ctx->enabled) {
+		msg_err("fuzzy_check module is not enabled");
+		rspamd_controller_send_error(conn_ent, 500, "Module disabled");
+		return 0;
+	}
+
+	if (fuzzy_module_ctx->fuzzy_rules == NULL) {
+		msg_err("fuzzy_check module has no rules defined");
+		rspamd_controller_send_error(conn_ent, 500, "Module has no rules");
+		return 0;
+	}
+
+	/* Get size */
+	arg = rspamd_http_message_find_header(msg, "Weight");
+	if (arg) {
+		errno = 0;
+
+		if (!rspamd_strtol(arg->begin, arg->len, &value)) {
+			msg_info("error converting numeric argument %T", arg);
+		}
+	}
+
+	arg = rspamd_http_message_find_header(msg, "Flag");
+	if (arg) {
+		errno = 0;
+
+		if (!rspamd_strtol(arg->begin, arg->len, &flag)) {
+			msg_info("error converting numeric argument %T", arg);
+			flag = 0;
+		}
+	}
+	else {
+		flag = 0;
+		arg = rspamd_http_message_find_header(msg, "Symbol");
+
+		/* Search flag by symbol */
+		if (arg) {
+			struct fuzzy_rule *rule;
+			guint i;
+			GHashTableIter it;
+			gpointer k, v;
+			struct fuzzy_mapping *map;
+
+			PTR_ARRAY_FOREACH(fuzzy_module_ctx->fuzzy_rules, i, rule)
+			{
+				if (flag != 0) {
+					break;
+				}
+
+				g_hash_table_iter_init(&it, rule->mappings);
+
+				while (g_hash_table_iter_next(&it, &k, &v)) {
+					map = v;
+
+					if (strlen(map->symbol) == arg->len &&
+						rspamd_lc_cmp(map->symbol, arg->begin, arg->len) == 0) {
+						flag = map->fuzzy_flag;
+						break;
+					}
+				}
+			}
+		}
+	}
+
+	if (flag == 0) {
+		msg_err("no flag defined to learn fuzzy");
+		rspamd_controller_send_error(conn_ent, 404, "Unknown or missing flag");
+		return 0;
+	}
+
+	arg = rspamd_http_message_find_header(msg, "Skip-Images");
+	if (arg) {
+		send_flags |= FUZZY_CHECK_FLAG_NOIMAGES;
+	}
+
+	arg = rspamd_http_message_find_header(msg, "Skip-Attachments");
+	if (arg) {
+		send_flags |= FUZZY_CHECK_FLAG_NOATTACHMENTS;
+	}
+
+	arg = rspamd_http_message_find_header(msg, "Skip-Text");
+	if (arg) {
+		send_flags |= FUZZY_CHECK_FLAG_NOTEXT;
+	}
+
+	fuzzy_process_handler(conn_ent, msg, cmd, value, flag,
+						  (struct fuzzy_ctx *) ctx, is_hash, send_flags);
+
+	return 0;
+}
+
+static inline gint
+fuzzy_check_send_lua_learn(struct fuzzy_rule *rule,
+						   struct rspamd_task *task,
+						   GPtrArray *commands,
+						   gint *saved)
+{
+	struct fuzzy_learn_session *s;
+	struct upstream *selected;
+	rspamd_inet_addr_t *addr;
+	gint sock;
+	gint ret = -1;
+
+	/* Get upstream */
+	if (!rspamd_session_blocked(task->s)) {
+		while ((selected = rspamd_upstream_get(rule->servers,
+											   RSPAMD_UPSTREAM_SEQUENTIAL, NULL, 0))) {
+			/* Create UDP socket */
+			addr = rspamd_upstream_addr_next(selected);
+
+			if ((sock = rspamd_inet_address_connect(addr,
+													SOCK_DGRAM, TRUE)) == -1) {
+				rspamd_upstream_fail(selected, TRUE, strerror(errno));
+			}
+			else {
+				s =
+					rspamd_mempool_alloc0(task->task_pool,
+										  sizeof(struct fuzzy_learn_session));
+				s->task = task;
+				s->commands = commands;
+				s->http_entry = NULL;
+				s->server = selected;
+				s->saved = saved;
+				s->fd = sock;
+				s->rule = rule;
+				s->session = task->s;
+				s->event_loop = task->event_loop;
+
+				rspamd_ev_watcher_init(&s->ev,
+									   sock,
+									   EV_WRITE,
+									   fuzzy_controller_io_callback,
+									   s);
+				rspamd_ev_watcher_start(s->event_loop, &s->ev,
+										rule->io_timeout);
+
+				rspamd_session_add_event(task->s,
+										 fuzzy_controller_lua_fin,
+										 s,
+										 M);
+
+				(*saved)++;
+				ret = 1;
+			}
+		}
+	}
+
+	return ret;
+}
+
+static gboolean
+fuzzy_check_lua_process_learn(struct rspamd_task *task,
+							  gint cmd, gint value, gint flag, guint send_flags)
+{
+	struct fuzzy_rule *rule;
+	gboolean processed = FALSE, res = TRUE;
+	guint i;
+	GPtrArray *commands;
+	gint *saved, rules = 0;
+	struct fuzzy_ctx *fuzzy_module_ctx = fuzzy_get_context(task->cfg);
+
+	saved = rspamd_mempool_alloc0(task->task_pool, sizeof(gint));
+
+	PTR_ARRAY_FOREACH(fuzzy_module_ctx->fuzzy_rules, i, rule)
+	{
+		if (!res) {
+			break;
+		}
+		if (rule->read_only) {
+			continue;
+		}
+
+		/* Check for flag */
+		if (g_hash_table_lookup(rule->mappings,
+								GINT_TO_POINTER(flag)) == NULL) {
+			msg_info_task("skip rule %s as it has no flag %d defined"
+						  " false",
+						  rule->name, flag);
+			continue;
+		}
+
+		rules++;
+
+		res = 0;
+		commands = fuzzy_generate_commands(task, rule, cmd, flag,
+										   value, send_flags);
+
+		if (commands != NULL) {
+			res = fuzzy_check_send_lua_learn(rule, task, commands,
+											 saved);
+			rspamd_mempool_add_destructor(task->task_pool,
+										  rspamd_ptr_array_free_hard, commands);
+		}
+
+		if (res) {
+			processed = TRUE;
+		}
+	}
+
+	if (res == -1) {
+		msg_warn_task("cannot send fuzzy request: %s",
+					  strerror(errno));
+	}
+	else if (!processed) {
+		if (rules) {
+			msg_warn_task("no content to generate fuzzy");
+
+			return FALSE;
+		}
+		else {
+			msg_warn_task("no fuzzy rules found for flag %d", flag);
+			return FALSE;
+		}
+	}
+
+	return TRUE;
+}
+
+static gint
+fuzzy_lua_learn_handler(lua_State *L)
+{
+	struct rspamd_task *task = lua_check_task(L, 1);
+
+	if (task == NULL) {
+		return luaL_error(L, "invalid arguments");
+	}
+
+	guint flag = 0, weight = 1, send_flags = 0;
+	const gchar *symbol;
+	struct fuzzy_ctx *fuzzy_module_ctx = fuzzy_get_context(task->cfg);
+
+	if (lua_type(L, 2) == LUA_TNUMBER) {
+		flag = lua_tointeger(L, 2);
+	}
+	else if (lua_type(L, 2) == LUA_TSTRING) {
+		struct fuzzy_rule *rule;
+		guint i;
+		GHashTableIter it;
+		gpointer k, v;
+		struct fuzzy_mapping *map;
+
+		symbol = lua_tostring(L, 2);
+
+		PTR_ARRAY_FOREACH(fuzzy_module_ctx->fuzzy_rules, i, rule)
+		{
+			if (flag != 0) {
+				break;
+			}
+
+			g_hash_table_iter_init(&it, rule->mappings);
+
+			while (g_hash_table_iter_next(&it, &k, &v)) {
+				map = v;
+
+				if (g_ascii_strcasecmp(symbol, map->symbol) == 0) {
+					flag = map->fuzzy_flag;
+					break;
+				}
+			}
+		}
+	}
+
+	if (flag == 0) {
+		return luaL_error(L, "bad flag");
+	}
+
+	if (lua_type(L, 3) == LUA_TNUMBER) {
+		weight = lua_tonumber(L, 3);
+	}
+
+	if (lua_type(L, 4) == LUA_TTABLE) {
+		const gchar *sf;
+
+		for (lua_pushnil(L); lua_next(L, -2); lua_pop(L, 1)) {
+			sf = lua_tostring(L, -1);
+
+			if (sf) {
+				if (g_ascii_strcasecmp(sf, "noimages") == 0) {
+					send_flags |= FUZZY_CHECK_FLAG_NOIMAGES;
+				}
+				else if (g_ascii_strcasecmp(sf, "noattachments") == 0) {
+					send_flags |= FUZZY_CHECK_FLAG_NOATTACHMENTS;
+				}
+				else if (g_ascii_strcasecmp(sf, "notext") == 0) {
+					send_flags |= FUZZY_CHECK_FLAG_NOTEXT;
+				}
+			}
+		}
+	}
+
+	lua_pushboolean(L,
+					fuzzy_check_lua_process_learn(task, FUZZY_WRITE, weight, flag,
+												  send_flags));
+	return 1;
+}
+
+static gint
+fuzzy_lua_unlearn_handler(lua_State *L)
+{
+	struct rspamd_task *task = lua_check_task(L, 1);
+	if (task == NULL) {
+		return luaL_error(L, "invalid arguments");
+	}
+
+	guint flag = 0, weight = 1.0, send_flags = 0;
+	const gchar *symbol;
+	struct fuzzy_ctx *fuzzy_module_ctx = fuzzy_get_context(task->cfg);
+
+	if (lua_type(L, 2) == LUA_TNUMBER) {
+		flag = lua_tointeger(L, 2);
+	}
+	else if (lua_type(L, 2) == LUA_TSTRING) {
+		struct fuzzy_rule *rule;
+		guint i;
+		GHashTableIter it;
+		gpointer k, v;
+		struct fuzzy_mapping *map;
+
+		symbol = lua_tostring(L, 2);
+
+		PTR_ARRAY_FOREACH(fuzzy_module_ctx->fuzzy_rules, i, rule)
+		{
+
+			if (flag != 0) {
+				break;
+			}
+
+			g_hash_table_iter_init(&it, rule->mappings);
+
+			while (g_hash_table_iter_next(&it, &k, &v)) {
+				map = v;
+
+				if (g_ascii_strcasecmp(symbol, map->symbol) == 0) {
+					flag = map->fuzzy_flag;
+					break;
+				}
+			}
+		}
+	}
+
+	if (flag == 0) {
+		return luaL_error(L, "bad flag");
+	}
+
+	if (lua_type(L, 3) == LUA_TNUMBER) {
+		weight = lua_tonumber(L, 3);
+	}
+
+	if (lua_type(L, 4) == LUA_TTABLE) {
+		const gchar *sf;
+
+		for (lua_pushnil(L); lua_next(L, -2); lua_pop(L, 1)) {
+			sf = lua_tostring(L, -1);
+
+			if (sf) {
+				if (g_ascii_strcasecmp(sf, "noimages") == 0) {
+					send_flags |= FUZZY_CHECK_FLAG_NOIMAGES;
+				}
+				else if (g_ascii_strcasecmp(sf, "noattachments") == 0) {
+					send_flags |= FUZZY_CHECK_FLAG_NOATTACHMENTS;
+				}
+				else if (g_ascii_strcasecmp(sf, "notext") == 0) {
+					send_flags |= FUZZY_CHECK_FLAG_NOTEXT;
+				}
+			}
+		}
+	}
+
+	lua_pushboolean(L,
+					fuzzy_check_lua_process_learn(task, FUZZY_DEL, weight, flag,
+												  send_flags));
+
+	return 1;
+}
+
+static gint
+fuzzy_lua_gen_hashes_handler(lua_State *L)
+{
+	struct rspamd_task *task = lua_check_task(L, 1);
+
+	if (task == NULL) {
+		return luaL_error(L, "invalid arguments");
+	}
+
+	guint flag = 0, weight = 1, send_flags = 0;
+	const gchar *symbol;
+	struct fuzzy_ctx *fuzzy_module_ctx = fuzzy_get_context(task->cfg);
+	struct fuzzy_rule *rule;
+	GPtrArray *commands;
+	gint cmd = FUZZY_WRITE;
+	gint i;
+
+	if (lua_type(L, 2) == LUA_TNUMBER) {
+		flag = lua_tonumber(L, 2);
+	}
+	else if (lua_type(L, 2) == LUA_TSTRING) {
+		struct fuzzy_rule *rule;
+		GHashTableIter it;
+		gpointer k, v;
+		struct fuzzy_mapping *map;
+
+		symbol = lua_tostring(L, 2);
+
+		PTR_ARRAY_FOREACH(fuzzy_module_ctx->fuzzy_rules, i, rule)
+		{
+			if (flag != 0) {
+				break;
+			}
+
+			g_hash_table_iter_init(&it, rule->mappings);
+
+			while (g_hash_table_iter_next(&it, &k, &v)) {
+				map = v;
+
+				if (g_ascii_strcasecmp(symbol, map->symbol) == 0) {
+					flag = map->fuzzy_flag;
+					break;
+				}
+			}
+		}
+	}
+
+	if (flag == 0) {
+		return luaL_error(L, "bad flag");
+	}
+
+	if (lua_type(L, 3) == LUA_TNUMBER) {
+		weight = lua_tonumber(L, 3);
+	}
+
+	/* Flags */
+	if (lua_type(L, 4) == LUA_TTABLE) {
+		const gchar *sf;
+
+		for (lua_pushnil(L); lua_next(L, -2); lua_pop(L, 1)) {
+			sf = lua_tostring(L, -1);
+
+			if (sf) {
+				if (g_ascii_strcasecmp(sf, "noimages") == 0) {
+					send_flags |= FUZZY_CHECK_FLAG_NOIMAGES;
+				}
+				else if (g_ascii_strcasecmp(sf, "noattachments") == 0) {
+					send_flags |= FUZZY_CHECK_FLAG_NOATTACHMENTS;
+				}
+				else if (g_ascii_strcasecmp(sf, "notext") == 0) {
+					send_flags |= FUZZY_CHECK_FLAG_NOTEXT;
+				}
+			}
+		}
+	}
+
+	/* Type */
+	if (lua_type(L, 5) == LUA_TSTRING) {
+		const gchar *cmd_name = lua_tostring(L, 5);
+
+		if (strcmp(cmd_name, "add") == 0 || strcmp(cmd_name, "write") == 0) {
+			cmd = FUZZY_WRITE;
+		}
+		else if (strcmp(cmd_name, "delete") == 0 || strcmp(cmd_name, "remove") == 0) {
+			cmd = FUZZY_DEL;
+		}
+		else {
+			return luaL_error(L, "invalid command: %s", cmd_name);
+		}
+	}
+
+	lua_createtable(L, 0, fuzzy_module_ctx->fuzzy_rules->len);
+
+	PTR_ARRAY_FOREACH(fuzzy_module_ctx->fuzzy_rules, i, rule)
+	{
+		if (rule->read_only) {
+			continue;
+		}
+
+		/* Check for flag */
+		if (g_hash_table_lookup(rule->mappings,
+								GINT_TO_POINTER(flag)) == NULL) {
+			msg_info_task("skip rule %s as it has no flag %d defined"
+						  " false",
+						  rule->name, flag);
+			continue;
+		}
+
+		commands = fuzzy_generate_commands(task, rule, cmd, flag,
+										   weight, send_flags);
+
+		if (commands != NULL) {
+			struct fuzzy_cmd_io *io;
+			gint j;
+
+			lua_pushstring(L, rule->name);
+			lua_createtable(L, commands->len, 0);
+
+			PTR_ARRAY_FOREACH(commands, j, io)
+			{
+				lua_pushlstring(L, io->io.iov_base, io->io.iov_len);
+				lua_rawseti(L, -2, j + 1);
+			}
+
+			lua_settable(L, -3); /* ret[rule->name] = {raw_fuzzy1, ..., raw_fuzzyn} */
+
+			g_ptr_array_free(commands, TRUE);
+		}
+	}
+
+
+	return 1;
+}
+
+static gint
+fuzzy_lua_hex_hashes_handler(lua_State *L)
+{
+	struct rspamd_task *task = lua_check_task(L, 1);
+
+	if (task == NULL) {
+		return luaL_error(L, "invalid arguments");
+	}
+
+	guint flag = 0, weight = 1, send_flags = 0;
+	const gchar *symbol;
+	struct fuzzy_ctx *fuzzy_module_ctx = fuzzy_get_context(task->cfg);
+	struct fuzzy_rule *rule;
+	GPtrArray *commands;
+	gint i;
+
+	if (lua_type(L, 2) == LUA_TNUMBER) {
+		flag = lua_tonumber(L, 2);
+	}
+	else if (lua_type(L, 2) == LUA_TSTRING) {
+		struct fuzzy_rule *rule;
+		GHashTableIter it;
+		gpointer k, v;
+		struct fuzzy_mapping *map;
+
+		symbol = lua_tostring(L, 2);
+
+		PTR_ARRAY_FOREACH(fuzzy_module_ctx->fuzzy_rules, i, rule)
+		{
+			if (flag != 0) {
+				break;
+			}
+
+			g_hash_table_iter_init(&it, rule->mappings);
+
+			while (g_hash_table_iter_next(&it, &k, &v)) {
+				map = v;
+
+				if (g_ascii_strcasecmp(symbol, map->symbol) == 0) {
+					flag = map->fuzzy_flag;
+					break;
+				}
+			}
+		}
+	}
+
+	if (flag == 0) {
+		return luaL_error(L, "bad flag");
+	}
+
+	lua_createtable(L, 0, fuzzy_module_ctx->fuzzy_rules->len);
+
+	PTR_ARRAY_FOREACH(fuzzy_module_ctx->fuzzy_rules, i, rule)
+	{
+		/* Check for flag */
+		if (g_hash_table_lookup(rule->mappings,
+								GINT_TO_POINTER(flag)) == NULL) {
+			msg_debug_task("skip rule %s as it has no flag %d defined"
+						   " false",
+						   rule->name, flag);
+			continue;
+		}
+
+		commands = fuzzy_generate_commands(task, rule, FUZZY_CHECK, flag,
+										   weight, send_flags);
+
+		lua_pushstring(L, rule->name);
+
+		if (commands != NULL) {
+			lua_createtable(L, commands->len, 0);
+			/*
+			 * We have all commands cached, so we can just read their cached value to
+			 * get hex hashes
+			 */
+			struct rspamd_mime_part *mp;
+			gint j, part_idx = 1;
+
+			PTR_ARRAY_FOREACH(MESSAGE_FIELD(task, parts), j, mp)
+			{
+				struct rspamd_cached_shingles *cached;
+
+				cached = fuzzy_cmd_get_cached(rule, task, mp);
+
+				if (cached) {
+					gchar hexbuf[rspamd_cryptobox_HASHBYTES * 2 + 1];
+					gint r = rspamd_encode_hex_buf(cached->digest, sizeof(cached->digest), hexbuf,
+												   sizeof(hexbuf));
+					lua_pushlstring(L, hexbuf, r);
+					lua_rawseti(L, -2, part_idx++);
+				}
+			}
+
+			g_ptr_array_free(commands, TRUE);
+		}
+		else {
+			lua_pushnil(L);
+		}
+
+		/* res[rule->name] = {hex_hash1, ..., hex_hashn} */
+		lua_settable(L, -3);
+	}
+
+	return 1;
+}
+
+static gboolean
+fuzzy_add_handler(struct rspamd_http_connection_entry *conn_ent,
+				  struct rspamd_http_message *msg, struct module_ctx *ctx)
+{
+	return fuzzy_controller_handler(conn_ent, msg,
+									ctx, FUZZY_WRITE, FALSE);
+}
+
+static gboolean
+fuzzy_delete_handler(struct rspamd_http_connection_entry *conn_ent,
+					 struct rspamd_http_message *msg, struct module_ctx *ctx)
+{
+	return fuzzy_controller_handler(conn_ent, msg,
+									ctx, FUZZY_DEL, FALSE);
+}
+
+static gboolean
+fuzzy_deletehash_handler(struct rspamd_http_connection_entry *conn_ent,
+						 struct rspamd_http_message *msg, struct module_ctx *ctx)
+{
+	return fuzzy_controller_handler(conn_ent, msg,
+									ctx, FUZZY_DEL, TRUE);
+}
+
+static int
+fuzzy_attach_controller(struct module_ctx *ctx, GHashTable *commands)
+{
+	struct fuzzy_ctx *fctx = (struct fuzzy_ctx *) ctx;
+	struct rspamd_custom_controller_command *cmd;
+
+	cmd = rspamd_mempool_alloc(fctx->fuzzy_pool, sizeof(*cmd));
+	cmd->privileged = TRUE;
+	cmd->require_message = TRUE;
+	cmd->handler = fuzzy_add_handler;
+	cmd->ctx = ctx;
+	g_hash_table_insert(commands, "/fuzzyadd", cmd);
+
+	cmd = rspamd_mempool_alloc(fctx->fuzzy_pool, sizeof(*cmd));
+	cmd->privileged = TRUE;
+	cmd->require_message = TRUE;
+	cmd->handler = fuzzy_delete_handler;
+	cmd->ctx = ctx;
+	g_hash_table_insert(commands, "/fuzzydel", cmd);
+
+	cmd = rspamd_mempool_alloc(fctx->fuzzy_pool, sizeof(*cmd));
+	cmd->privileged = TRUE;
+	cmd->require_message = FALSE;
+	cmd->handler = fuzzy_deletehash_handler;
+	cmd->ctx = ctx;
+	g_hash_table_insert(commands, "/fuzzydelhash", cmd);
+
+	return 0;
+}
+
+/* Lua handlers */
+/* TODO: move to a separate unit, as this file is now a bit too hard to read */
+
+static void
+lua_upstream_str_inserter(struct upstream *up, guint idx, void *ud)
+{
+	lua_State *L = (lua_State *) ud;
+
+	lua_pushstring(L, rspamd_upstream_name(up));
+	lua_rawseti(L, -2, idx + 1);
+}
+
+static gint
+fuzzy_lua_list_storages(lua_State *L)
+{
+	struct rspamd_config *cfg = lua_check_config(L, 1);
+
+	if (cfg == NULL) {
+		return luaL_error(L, "invalid arguments");
+	}
+
+	struct fuzzy_ctx *fuzzy_module_ctx = fuzzy_get_context(cfg);
+	struct fuzzy_rule *rule;
+	guint i;
+
+	lua_createtable(L, 0, fuzzy_module_ctx->fuzzy_rules->len);
+	PTR_ARRAY_FOREACH(fuzzy_module_ctx->fuzzy_rules, i, rule)
+	{
+		lua_newtable(L);
+
+		lua_pushboolean(L, rule->read_only);
+		lua_setfield(L, -2, "read_only");
+
+		/* Push servers */
+		lua_createtable(L, rspamd_upstreams_count(rule->servers), 0);
+		rspamd_upstreams_foreach(rule->servers, lua_upstream_str_inserter, L);
+		lua_setfield(L, -2, "servers");
+
+		/* Push flags */
+		GHashTableIter it;
+
+		lua_createtable(L, 0, g_hash_table_size(rule->mappings));
+		gpointer k, v;
+		struct fuzzy_mapping *map;
+
+		g_hash_table_iter_init(&it, rule->mappings);
+		while (g_hash_table_iter_next(&it, &k, &v)) {
+			map = v;
+
+			lua_pushinteger(L, map->fuzzy_flag);
+			lua_setfield(L, -2, map->symbol);
+		}
+		lua_setfield(L, -2, "flags");
+
+		/* Final table */
+		lua_setfield(L, -2, rule->name);
+	}
+
+	return 1;
+}
+
+struct fuzzy_lua_session {
+	struct rspamd_task *task;
+	lua_State *L;
+	rspamd_inet_addr_t *addr;
+	GPtrArray *commands;
+	struct fuzzy_rule *rule;
+	struct rspamd_io_ev ev;
+	gint cbref;
+	gint fd;
+};
+
+static void
+fuzzy_lua_session_fin(void *ud)
+{
+	struct fuzzy_lua_session *session = ud;
+
+	if (session->commands) {
+		g_ptr_array_free(session->commands, TRUE);
+	}
+
+	rspamd_ev_watcher_stop(session->task->event_loop, &session->ev);
+	luaL_unref(session->L, LUA_REGISTRYINDEX, session->cbref);
+}
+
+static gboolean
+fuzzy_lua_session_is_completed(struct fuzzy_lua_session *session)
+{
+	struct fuzzy_cmd_io *io;
+	guint nreplied = 0, i;
+
+
+	for (i = 0; i < session->commands->len; i++) {
+		io = g_ptr_array_index(session->commands, i);
+
+		if (io->flags & FUZZY_CMD_FLAG_REPLIED) {
+			nreplied++;
+		}
+	}
+
+	if (nreplied == session->commands->len) {
+
+		rspamd_session_remove_event(session->task->s, fuzzy_lua_session_fin, session);
+
+		return TRUE;
+	}
+
+	return FALSE;
+}
+
+static void
+fuzzy_lua_push_result(struct fuzzy_lua_session *session, gdouble latency)
+{
+	lua_rawgeti(session->L, LUA_REGISTRYINDEX, session->cbref);
+	lua_pushboolean(session->L, TRUE);
+	rspamd_lua_ip_push(session->L, session->addr);
+	lua_pushnumber(session->L, latency);
+
+	/* TODO: check results maybe? */
+	lua_pcall(session->L, 3, 0, 0);
+}
+
+#ifdef __GNUC__
+static void
+fuzzy_lua_push_error(struct fuzzy_lua_session *session, const gchar *err_fmt, ...) __attribute__((format(printf, 2, 3)));
+#endif
+
+static void
+fuzzy_lua_push_error(struct fuzzy_lua_session *session, const gchar *err_fmt, ...)
+{
+	va_list v;
+
+	va_start(v, err_fmt);
+	lua_rawgeti(session->L, LUA_REGISTRYINDEX, session->cbref);
+	lua_pushboolean(session->L, FALSE);
+	rspamd_lua_ip_push(session->L, session->addr);
+	lua_pushvfstring(session->L, err_fmt, v);
+	va_end(v);
+
+	/* TODO: check results maybe? */
+	lua_pcall(session->L, 3, 0, 0);
+}
+
+static gint
+fuzzy_lua_try_read(struct fuzzy_lua_session *session)
+{
+	const struct rspamd_fuzzy_reply *rep;
+	struct rspamd_fuzzy_cmd *cmd = NULL;
+	struct fuzzy_cmd_io *io = NULL;
+	gint r, ret;
+	guchar buf[2048], *p;
+
+	if ((r = read(session->fd, buf, sizeof(buf) - 1)) == -1) {
+		if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR) {
+			return 0;
+		}
+		else {
+			fuzzy_lua_push_error(session, "cannot read from socket: %s", strerror(errno));
+			return -1;
+		}
+	}
+	else {
+		p = buf;
+
+		ret = 0;
+
+		while ((rep = fuzzy_process_reply(&p, &r,
+										  session->commands, session->rule, &cmd, &io)) != NULL) {
+
+			if (rep->v1.prob > 0.5) {
+				if (cmd->cmd == FUZZY_PING) {
+					fuzzy_lua_push_result(session, fuzzy_milliseconds_since_midnight() - rep->v1.value);
+				}
+				else {
+					fuzzy_lua_push_error(session, "unsupported");
+				}
+			}
+			else {
+				fuzzy_lua_push_error(session, "invalid reply from server: %d", rep->v1.value);
+			}
+
+			ret = 1;
+		}
+	}
+
+	return ret;
+}
+
+/* Fuzzy check callback */
+static void
+fuzzy_lua_io_callback(gint fd, short what, void *arg)
+{
+	struct fuzzy_lua_session *session = arg;
+	gint r;
+
+	enum {
+		return_error = 0,
+		return_want_more,
+		return_finished
+	} ret = return_error;
+
+	if (what & EV_READ) {
+		/* Try to read reply */
+		r = fuzzy_lua_try_read(session);
+
+		switch (r) {
+		case 0:
+			if (what & EV_READ) {
+				ret = return_want_more;
+			}
+			else {
+				if (what & EV_WRITE) {
+					/* Retransmit attempt */
+					if (!fuzzy_cmd_vector_to_wire(fd, session->commands)) {
+						fuzzy_lua_push_error(session, "cannot write to socket");
+						ret = return_error;
+					}
+					else {
+						ret = return_want_more;
+					}
+				}
+			}
+			break;
+		case 1:
+			ret = return_finished;
+			break;
+		default:
+			ret = return_error;
+			break;
+		}
+	}
+	else if (what & EV_WRITE) {
+		if (!fuzzy_cmd_vector_to_wire(fd, session->commands)) {
+			fuzzy_lua_push_error(session, "cannot write to socket");
+			ret = return_error;
+		}
+		else {
+			ret = return_want_more;
+		}
+	}
+	else {
+		/* Timeout */
+		fuzzy_lua_push_error(session, "timeout waiting for the reply");
+		ret = return_error;
+	}
+
+	if (ret == return_want_more) {
+		/* Processed write, switch to reading */
+		rspamd_ev_watcher_reschedule(session->task->event_loop,
+									 &session->ev, EV_READ);
+	}
+	else if (ret == return_error) {
+		rspamd_session_remove_event(session->task->s, fuzzy_lua_session_fin, session);
+	}
+	else {
+		/* Read something from network */
+		if (!fuzzy_lua_session_is_completed(session)) {
+			/* Need to read more */
+			rspamd_ev_watcher_reschedule(session->task->event_loop,
+										 &session->ev, EV_READ);
+		}
+	}
+}
+
+/***
+ * @function fuzzy_check.ping_storage(task, callback, rule, timeout[, server_override])
+ * @return
+ */
+static gint
+fuzzy_lua_ping_storage(lua_State *L)
+{
+	struct rspamd_task *task = lua_check_task(L, 1);
+
+	if (task == NULL) {
+		return luaL_error(L, "invalid arguments: task");
+	}
+
+	/* Other arguments sanity */
+	if (lua_type(L, 2) != LUA_TFUNCTION || lua_type(L, 3) != LUA_TSTRING || lua_type(L, 4) != LUA_TNUMBER) {
+		return luaL_error(L, "invalid arguments: callback/rule/timeout argument");
+	}
+
+	struct fuzzy_ctx *fuzzy_module_ctx = fuzzy_get_context(task->cfg);
+	struct fuzzy_rule *rule, *rule_found = NULL;
+	int i;
+	const char *rule_name = lua_tostring(L, 3);
+
+	PTR_ARRAY_FOREACH(fuzzy_module_ctx->fuzzy_rules, i, rule)
+	{
+		if (strcmp(rule->name, rule_name) == 0) {
+			rule_found = rule;
+			break;
+		}
+	}
+
+	if (rule_found == NULL) {
+		return luaL_error(L, "invalid arguments: no such rule defined");
+	}
+
+	rspamd_inet_addr_t *addr = NULL;
+
+	if (lua_type(L, 5) == LUA_TSTRING) {
+		const gchar *server_name = lua_tostring(L, 5);
+		enum rspamd_parse_host_port_result res;
+		GPtrArray *addrs = g_ptr_array_new();
+
+		/* We resolve address synchronously here! Why? Because it is an override... */
+		res = rspamd_parse_host_port_priority(server_name, &addrs, 0, NULL,
+											  11335, FALSE, task->task_pool);
+
+		if (res == RSPAMD_PARSE_ADDR_FAIL) {
+			lua_pushboolean(L, FALSE);
+			lua_pushfstring(L, "invalid arguments: cannot resolve %s", server_name);
+			return 2;
+		}
+
+		/* Get random address */
+		addr = rspamd_inet_address_copy(g_ptr_array_index(addrs, rspamd_random_uint64_fast() % addrs->len),
+										task->task_pool);
+		rspamd_mempool_add_destructor(task->task_pool,
+									  rspamd_ptr_array_free_hard, addrs);
+	}
+	else {
+		struct upstream *selected = rspamd_upstream_get(rule_found->servers,
+														RSPAMD_UPSTREAM_ROUND_ROBIN, NULL, 0);
+		addr = rspamd_upstream_addr_next(selected);
+	}
+
+	if (addr != NULL) {
+		int sock;
+		GPtrArray *commands = fuzzy_generate_commands(task, rule, FUZZY_PING, 0, 0, 0);
+
+		if ((sock = rspamd_inet_address_connect(addr, SOCK_DGRAM, TRUE)) == -1) {
+			lua_pushboolean(L, FALSE);
+			lua_pushfstring(L, "cannot connect to %s, %s",
+							rspamd_inet_address_to_string_pretty(addr),
+							strerror(errno));
+			return 2;
+		}
+		else {
+			/* Create a dedicated ping session for a socket */
+			struct fuzzy_lua_session *session =
+				rspamd_mempool_alloc0(task->task_pool,
+									  sizeof(struct fuzzy_lua_session));
+			session->task = task;
+			session->fd = sock;
+			session->addr = addr;
+			session->commands = commands;
+			session->L = L;
+			session->rule = rule_found;
+			/* Store callback */
+			lua_pushvalue(L, 2);
+			session->cbref = luaL_ref(L, LUA_REGISTRYINDEX);
+
+			rspamd_session_add_event(task->s, fuzzy_lua_session_fin, session, M);
+			rspamd_ev_watcher_init(&session->ev,
+								   sock,
+								   EV_WRITE,
+								   fuzzy_lua_io_callback,
+								   session);
+			rspamd_ev_watcher_start(session->task->event_loop, &session->ev,
+									lua_tonumber(L, 4));
+		}
+	}
+
+	lua_pushboolean(L, TRUE);
+	return 1;
+}
\ No newline at end of file