Add support for wildcard in mysql_query_rules.client_addr sysown#1450

Input validation:
- client_addr not longer than INET6_ADDRSTRLEN
- % allowed only at the end of client_addr

Query rule itself remembers if there is a wildcard or not.
If there is a wildcard compares string till the wildcard.
If client_addr=='%' , it is a match all.

include/query_processor.h

@@ -14,6 +14,7 @@ struct _Query_Processor_rule_t {
 	char *schemaname;
 	int flagIN;
 	char *client_addr;
+	int client_addr_wildcard_position;
 	char *proxy_addr;
 	int proxy_port;
 	uint64_t digest;

lib/ProxySQL_Admin.cpp

@@ -7070,6 +7070,22 @@ char * ProxySQL_Admin::load_mysql_query_rules_to_runtime() {
 		QP_rule_t * nqpr;
 		for (std::vector<SQLite3_row *>::iterator it = resultset->rows.begin() ; it != resultset->rows.end(); ++it) {
 			SQLite3_row *r=*it;
+			if (r->fields[4]) {
+				char *pct = NULL;
+				if (strlen(r->fields[4]) >= INET6_ADDRSTRLEN) {
+					proxy_error("Query rule with rule_id=%s has an invalid client_addr: %s\n", r->fields[0], r->fields[4]);
+					continue;
+				}
+				pct = strchr(r->fields[4],'%');
+				if (pct) { // there is a wildcard
+					if (strlen(pct) == 1) {
+						// % is at the end of the string, good
+					} else {
+						proxy_error("Query rule with rule_id=%s has a wildcard that is not at the end of client_addr: %s\n", r->fields[0], r->fields[4]);
+						continue;
+					}
+				}
+			}
 			nqpr=GloQPro->new_query_rule(
 				atoi(r->fields[0]), // rule_id
 				true,

lib/Query_Processor.cpp

@@ -495,7 +495,23 @@ QP_rule_t * Query_Processor::new_query_rule(int rule_id, bool active, char *user
 	newQR->regex_engine2=NULL;
 	newQR->hits=0;
 
+	newQR->client_addr_wildcard_position = -1; // not existing by default
 	newQR->client_addr=(client_addr ? strdup(client_addr) : NULL);
+	if (newQR->client_addr) {
+		char *pct = strchr(newQR->client_addr,'%');
+		if (pct) { // there is a wildcard . We assume Admin did already all the input validation
+			if (pct == newQR->client_addr) {
+				// client_addr == '%'
+				// % is at the end of the string, but also at the beginning
+				// becoming a catch all
+				newQR->client_addr_wildcard_position = 0;
+			} else {
+				// this math is valid also if (pct == newQR->client_addr)
+				// but we separate it to clarify that client_addr_wildcard_position is a match all
+				newQR->client_addr_wildcard_position = strlen(newQR->client_addr) - strlen(pct);
+			}
+		}
+	}
 	newQR->proxy_addr=(proxy_addr ? strdup(proxy_addr) : NULL);
 	newQR->proxy_port=proxy_port;
 	newQR->log=log;
@@ -957,9 +973,19 @@ Query_Processor_Output * Query_Processor::process_mysql_query(MySQL_Session *ses
 		// match on client address
 		if (qr->client_addr && strlen(qr->client_addr)) {
 			if (sess->client_myds->addr.addr) {
-				if (strcmp(qr->client_addr,sess->client_myds->addr.addr)!=0) {
-					proxy_debug(PROXY_DEBUG_MYSQL_QUERY_PROCESSOR, 5, "query rule %d has no matching client_addr\n", qr->rule_id);
-					continue;
+				if (qr->client_addr_wildcard_position == -1) { // no wildcard , old algorithm
+					if (strcmp(qr->client_addr,sess->client_myds->addr.addr)!=0) {
+						proxy_debug(PROXY_DEBUG_MYSQL_QUERY_PROCESSOR, 5, "query rule %d has no matching client_addr\n", qr->rule_id);
+						continue;
+					}
+				} else if (qr->client_addr_wildcard_position==0) {
+					// catch all!
+					// therefore we have a match
+				} else { // client_addr_wildcard_position > 0
+					if (strncmp(qr->client_addr,sess->client_myds->addr.addr,qr->client_addr_wildcard_position)!=0) {
+						proxy_debug(PROXY_DEBUG_MYSQL_QUERY_PROCESSOR, 5, "query rule %d has no matching client_addr\n", qr->rule_id);
+						continue;
+					}
 				}
 			}
 		}