diff --git a/modules/userblacklist/userblacklist.c b/modules/userblacklist/userblacklist.c
index 58d7a372c21..3ca85b7b237 100644
--- a/modules/userblacklist/userblacklist.c
+++ b/modules/userblacklist/userblacklist.c
@@ -62,12 +62,11 @@ static str db_table     = str_init("userblacklist");
 static int use_domain   = 0;
 
 /* ---- fixup functions: */
-static int check_blacklist_fixup(void** param, int param_no);
-static int check_user_blacklist_fixup(void** param, int param_no);
+static int check_blacklist_fixup(void** param);
 
 /* ---- exported commands: */
-static int check_user_blacklist(struct sip_msg *msg, char* str1, char* str2, char* str3, char* str4);
-static int check_blacklist(struct sip_msg *msg, struct check_blacklist_fs_t *arg1);
+static int check_user_blacklist(struct sip_msg *msg, str *user, str *domain, str *number, str *table);
+static int check_blacklist(struct sip_msg *msg, struct dt_node_t *root);
 
 /* ---- module init functions: */
 static int mod_init(void);
@@ -80,14 +79,18 @@ mi_response_t *mi_reload_blacklist(const mi_params_t *params,
 
 
 static cmd_export_t cmds[]={
-	{ "check_user_blacklist", (cmd_function)check_user_blacklist, 2, check_user_blacklist_fixup, 0, REQUEST_ROUTE | FAILURE_ROUTE },
-	{ "check_user_blacklist", (cmd_function)check_user_blacklist, 3, check_user_blacklist_fixup, 0, REQUEST_ROUTE | FAILURE_ROUTE },
-	{ "check_user_blacklist", (cmd_function)check_user_blacklist, 4, check_user_blacklist_fixup, 0, REQUEST_ROUTE | FAILURE_ROUTE },
-	{ "check_blacklist", (cmd_function)check_blacklist, 1, check_blacklist_fixup, 0, REQUEST_ROUTE | FAILURE_ROUTE },
-	{ 0, 0, 0, 0, 0, 0}
+	{"check_user_blacklist", (cmd_function)check_user_blacklist, {
+		{CMD_PARAM_STR,0,0},
+		{CMD_PARAM_STR,0,0},
+		{CMD_PARAM_STR|CMD_PARAM_OPT,0,0},
+		{CMD_PARAM_STR|CMD_PARAM_OPT,0,0}, {0,0,0}},
+		REQUEST_ROUTE | FAILURE_ROUTE},
+	{"check_blacklist", (cmd_function)check_blacklist, {
+		{CMD_PARAM_STR, check_blacklist_fixup, 0}, {0,0,0}},
+		REQUEST_ROUTE | FAILURE_ROUTE},
+	{0,0,{{0,0,0}},0}
 };
 
-
 static param_export_t params[] = {
 	{ "db_url",          STR_PARAM, &db_url.s },
 	{ "db_table",        STR_PARAM, &db_table.s },
@@ -155,101 +158,22 @@ static struct source_list_t *sources = NULL;
 static struct dt_node_t *dt_root;
 
 
-static int check_user_blacklist_fixup(void** param, int param_no)
-{
-	pv_elem_t *model=NULL;
-	str s;
-
-	/* convert to str */
-	s.s = (char*)*param;
-	s.len = strlen(s.s);
-
-	if (param_no > 0 && param_no <= 4) {
-		if(s.len == 0 && param_no != 4) {
-			LM_ERR("no parameter %d\n", param_no);
-			return E_UNSPEC;
-		}
-
-		if(pv_parse_format(&s, &model) < 0 || !model) {
-			LM_ERR("wrong format [%.*s] for parameter %d\n", s.len, s.s, param_no);
-			return E_UNSPEC;
-		}
-
-		if(!model->spec.getf) {
-			if(param_no == 1) {
-				if(str2int(&s, (unsigned int*)&model->spec.pvp.pvn.u.isname.name.n) != 0) {
-					LM_ERR("wrong value [%.*s] for parameter %d\n", s.len, s.s, param_no);
-					return E_UNSPEC;
-				}
-			} else {
-				if(param_no == 2 || param_no == 3) {
-					LM_ERR("wrong value [%.*s] for parameter %d\n", s.len, s.s, param_no);
-					return E_UNSPEC;
-				} else {
-					// only a string
-					return 0;
-				}
-			}
-		}
-		*param = (void*)model;
-	} else {
-		LM_ERR("wrong number of parameters\n");
-	}
-
-	return 0;
-}
-
-
-static int check_user_blacklist(struct sip_msg *msg, char* str1, char* str2, char* str3, char* str4)
+static int check_user_blacklist(struct sip_msg *msg, str *user, str *domain, str *number, str *table)
 {
-	str user = { .len = 0, .s = NULL };
-	str domain = { .len = 0, .s = NULL};
-	str table = { .len = 0, .s = NULL};
-	str number = { .len = 0, .s = NULL};
-
 	char whitelist;
 	char *src;
     char *dst;
 	char req_number[MAXNUMBERLEN+1];
 
-	/* user */
-	if(((pv_elem_p)str1)->spec.getf) {
-		if(pv_printf_s(msg, (pv_elem_p)str1, &user) != 0) {
-			LM_ERR("cannot print user pseudo-variable\n");
-			return -1;
-		}
-	}
-	/* domain */
-	if(((pv_elem_p)str2)->spec.getf) {
-		if(pv_printf_s(msg, (pv_elem_p)str2, &domain) != 0) {
-			LM_ERR("cannot print domain pseudo-variable\n");
-			return -1;
-		}
-	}
-	/* source number */
-	if(str3 != NULL && ((pv_elem_p)str3)->spec.getf) {
-		if(pv_printf_s(msg, (pv_elem_p)str3, &number) != 0) {
-			LM_ERR("cannot print number pseudo-variable\n");
-			return -1;
-		}
-	}
-	/* table name */
-	if(str4 != NULL && strlen(str4) > 0) {
-		/* string */
-		table.s=str4;
-		table.len=strlen(str4);
-	} else {
-		/* use default table name */
-		table.len=db_table.len;
-		table.s=db_table.s;
-	}
+	if (!table)
+		table = &db_table;
 
 	if (msg->first_line.type != SIP_REQUEST) {
 		LM_ERR("SIP msg is not a request\n");
 		return -1;
 	}
 
-	if(number.s == NULL) {
+	if(number == NULL) {
 		/* use R-URI */
 		if ((parse_sip_msg_uri(msg) < 0) || (!msg->parsed_uri.user.s) || (msg->parsed_uri.user.len > MAXNUMBERLEN)) {
 			LM_ERR("cannot parse msg URI\n");
@@ -258,17 +182,17 @@ static int check_user_blacklist(struct sip_msg *msg, char* str1, char* str2, cha
 		strncpy(req_number, msg->parsed_uri.user.s, msg->parsed_uri.user.len);
 		req_number[msg->parsed_uri.user.len] = '\0';
 	} else {
-		if (number.len > MAXNUMBERLEN) {
+		if (number->len > MAXNUMBERLEN) {
 			LM_ERR("number to long\n");
 			return -1;
 		}
-		strncpy(req_number, number.s, number.len);
-		req_number[number.len] = '\0';
+		strncpy(req_number, number->s, number->len);
+		req_number[number->len] = '\0';
 	}
 
 	LM_DBG("check entry %s for user %.*s on domain %.*s in table %.*s\n", req_number,
-		user.len, user.s, domain.len, domain.s, table.len, table.s);
-	if (db_build_userbl_tree(&user, &domain, &table, dt_root, use_domain) < 0) {
+		user->len, user->s, domain->len, domain->s, table->len, table->s);
+	if (db_build_userbl_tree(user, domain, table, dt_root, use_domain) < 0) {
 		LM_ERR("cannot build d-tree\n");
 		return -1;
 	}
@@ -302,15 +226,15 @@ static int check_user_blacklist(struct sip_msg *msg, char* str1, char* str2, cha
  * Finds d-tree root for given table.
  * \return pointer to d-tree root on success, NULL otherwise
  */
-static struct dt_node_t *table2dt(const char *table)
+static struct dt_node_t *table2dt(str *table)
 {
 	struct source_t *src = sources->head;
 	while (src) {
-		if (strcmp(table, src->table) == 0) return src->dt_root;
+		if (strncmp(table->s, src->table, table->len) == 0) return src->dt_root;
 		src = src->next;
 	}
 
-	LM_ERR("invalid table '%s'.\n", table);
+	LM_ERR("invalid table '%.*s'.\n", table->len, table->s);
 	return NULL;
 }
 
@@ -320,12 +244,12 @@ static struct dt_node_t *table2dt(const char *table)
  * already present, nothing will be done.
  * \return zero on success, negative on errors
  */
-static int add_source(const char *table)
+static int add_source(str *table)
 {
 	/* check if the table is already present */
 	struct source_t *src = sources->head;
 	while (src) {
-		if (strcmp(table, src->table) == 0) return 0;
+		if (strncmp(table->s, src->table, table->len) == 0) return 0;
 		src = src->next;
 	}
 
@@ -339,59 +263,44 @@ static int add_source(const char *table)
 	src->next = sources->head;
 	sources->head = src;
 
-	src->table = shm_malloc(strlen(table)+1);
+	src->table = shm_malloc(table->len+1);
 	if (!src->table) {
 		LM_ERR("out of shared memory.\n");
 		shm_free(src);
 		return -1;
 	}
-	strcpy(src->table, table);
-	LM_DBG("add table %s", table);
+	strncpy(src->table, table->s, table->len);
+	src->table[table->len] = 0;
+	LM_DBG("add table %.*s", table->len, table->s);
 
 	return dt_init(&(src->dt_root));
 }
 
 
-static int check_blacklist_fixup(void **arg, int arg_no)
-{
-	char *table = (char *)(*arg);
-	struct dt_node_t *node = NULL;
-	if (arg_no != 1) {
-		LM_ERR("wrong number of parameters\n");
-		return -1;
-	}
+static int check_blacklist_fixup(void **arg)
+{	
+	struct dt_node_t *node;
 
-	if (!table) {
-		LM_ERR("no table name\n");
-		return -1;
-	}
 	/* try to add the table */
-	if (add_source(table) != 0) {
+	if (add_source((str*)*arg) != 0) {
 		LM_ERR("could not add table\n");
 		return -1;
 	}
 
 	/* get the node that belongs to the table */
-	node = table2dt(table);
+	node = table2dt((str*)*arg);
 	if (!node) {
-		LM_ERR("invalid table '%s'\n", table);
+		LM_ERR("invalid table '%.*s'\n", ((str*)*arg)->len, ((str*)*arg)->s);
 		return -1;
 	}
 
-	struct check_blacklist_fs_t *new_arg = (struct check_blacklist_fs_t*)pkg_malloc(sizeof(struct check_blacklist_fs_t));
-	if (!new_arg) {
-		LM_ERR("out of private memory\n");
-		return -1;
-	}
-	memset(new_arg, 0, sizeof(struct check_blacklist_fs_t));
-	new_arg->dt_root = node;
-	*arg=(void*)new_arg;
+	*arg = node;
 
 	return 0;
 }
 
 
-static int check_blacklist(struct sip_msg *msg, struct check_blacklist_fs_t *arg1)
+static int check_blacklist(struct sip_msg *msg, struct dt_node_t *root)
 {
 	char whitelist;
 	char *src;
@@ -429,7 +338,7 @@ static int check_blacklist(struct sip_msg *msg, struct check_blacklist_fs_t *arg
 	/* we guard the dt_root */
 	lock_get(lock);
 	LM_DBG("check entry %s\n", req_number);
-	if (dt_longest_match(arg1->dt_root, req_number, &whitelist) >= 0) {
+	if (dt_longest_match(root, req_number, &whitelist) >= 0) {
 		if (whitelist) {
 			/* LM_DBG("whitelisted\n"); */
 			lock_release(lock);