server: Support specific qtype to return SOA

ReadMe.md

@@ -541,6 +541,7 @@ https://github.com/pymumu/smartdns/releases
 |whitelist-ip|白名单IP地址|无|[ip/subnet]，可重复| whitelist-ip 1.2.3.4/16
 |blacklist-ip|黑名单IP地址|无|[ip/subnet]，可重复| blacklist-ip 1.2.3.4/16
 |force-AAAA-SOA|强制AAAA地址返回SOA|no|[yes\|no]|force-AAAA-SOA yes
+|force-qtype-SOA|强制指定qtype返回SOA|qtype id|[qtypeid | ...]|force-qtype-SOA 65 28
 |prefetch-domain|域名预先获取功能|no|[yes\|no]|prefetch-domain yes
 |serve-expired|过期缓存服务功能|no|[yes\|no]，开启此功能后，如果有请求时尝试回应TTL为0的过期记录，并并发查询记录，以避免查询等待|serve-expired yes
 |serve-expired-ttl|过期缓存服务最长超时时间|0|秒，0：表示停用超时，> 0表示指定的超时的秒数|serve-expired-ttl 0

ReadMe_en.md

@@ -528,6 +528,7 @@ Note: Merlin firmware is derived from ASUS firmware and can theoretically be use
 |whitelist-ip|ip whitelist|None|[ip/subnet], Repeatable，When the filtering server responds IPs in the IP whitelist, only result in whitelist will be accepted| whitelist-ip 1.2.3.4/16
 |blacklist-ip|ip blacklist|None|[ip/subnet], Repeatable，When the filtering server responds IPs in the IP blacklist, The result will be discarded directly| blacklist-ip 1.2.3.4/16
 |force-AAAA-SOA|force AAAA query return SOA|no|[yes\|no]|force-AAAA-SOA yes
+|force-qtype-SOA|force specific qtype return SOA|qtype id|[qtypeid | ...]|force-qtype-SOA 65 28
 |prefetch-domain|domain prefetch feature|no|[yes\|no]|prefetch-domain yes
 |serve-expired|Cache serve expired feature|no|[yes\|no], Attempts to serve old responses from cache with a TTL of 0 in the response without waiting for the actual resolution to finish.|serve-expired yes
 |serve-expired-ttl|Cache serve expired limite TTL|0|second，0：disable，> 0  seconds after expiration|serve-expired-ttl 0

etc/smartdns/smartdns.conf

@@ -84,6 +84,10 @@ cache-size 4096
 # force AAAA query return SOA
 # force-AAAA-SOA [yes|no]
 
+# force specific qtype return soa
+# force-qtype-SOA [qtypeid |...]
+# force-qtype-SOA 65 28
+
 # Enable IPV4, IPV6 dual stack IP optimization selection strategy
 # dualstack-ip-selection-threshold [num] (0~1000)
 # dualstack-ip-selection [yes|no]

src/dns_conf.c

@@ -37,6 +37,8 @@ struct dns_ipset_table {
 };
 static struct dns_ipset_table dns_ipset_table;
 
+struct dns_qtype_soa_table dns_qtype_soa_table;
+
 /* dns groups */
 struct dns_group_table dns_group_table;
 
@@ -1171,6 +1173,42 @@ static int _config_iplist_rule(char *subnet, enum address_rule rule)
 	return 0;
 }
 
+static int _config_qtype_soa(void *data, int argc, char *argv[])
+{
+	struct dns_qtype_soa_list *soa_list;
+	if (argc <= 1) {
+		return -1;
+	}
+
+	for (int i = 1; i < argc; i++) {
+		soa_list = malloc(sizeof(*soa_list));
+		if (soa_list == NULL) {
+			tlog(TLOG_ERROR, "cannot malloc memory");
+			return -1;
+		}
+
+		memset(soa_list, 0, sizeof(*soa_list));
+		soa_list->qtypeid = atol(argv[i]);
+		uint32_t key = hash_32_generic(soa_list->qtypeid, 32);
+		hash_add(dns_qtype_soa_table.qtype, &soa_list->node, key);
+	}
+
+	return 0;
+}
+
+static void _config_qtype_soa_table_destroy(void)
+{
+	struct dns_qtype_soa_list *soa_list = NULL;
+	struct hlist_node *tmp = NULL;
+	int i;
+
+	hash_for_each_safe(dns_qtype_soa_table.qtype, i, tmp, soa_list, node)
+	{
+		hlist_del_init(&soa_list->node);
+		free(soa_list);
+	}
+}
+
 static int _config_blacklist_ip(void *data, int argc, char *argv[])
 {
 	if (argc <= 1) {
@@ -1448,6 +1486,7 @@ static struct config_item _config_item[] = {
 	CONF_INT("rr-ttl-min", &dns_conf_rr_ttl_min, 0, CONF_INT_MAX),
 	CONF_INT("rr-ttl-max", &dns_conf_rr_ttl_max, 0, CONF_INT_MAX),
 	CONF_YESNO("force-AAAA-SOA", &dns_conf_force_AAAA_SOA),
+	CONF_CUSTOM("force-qtype-SOA", _config_qtype_soa, NULL),
 	CONF_CUSTOM("blacklist-ip", _config_blacklist_ip, NULL),
 	CONF_CUSTOM("whitelist-ip", _conf_whitelist_ip, NULL),
 	CONF_CUSTOM("bogus-nxdomain", _conf_bogus_nxdomain, NULL),
@@ -1518,6 +1557,7 @@ static int _dns_server_load_conf_init(void)
 	art_tree_init(&dns_conf_domain_rule);
 
 	hash_init(dns_ipset_table.ipset);
+	hash_init(dns_qtype_soa_table.qtype);
 	hash_init(dns_group_table.group);
 
 	return 0;
@@ -1530,6 +1570,7 @@ void dns_server_load_exit(void)
 	Destroy_Radix(dns_conf_address_rule.ipv6, _config_address_destroy, NULL);
 	_config_ipset_table_destroy();
 	_config_group_table_destroy();
+	_config_qtype_soa_table_destroy();
 }
 
 static int _dns_conf_speed_check_mode_verify(void)

src/dns_conf.h

@@ -203,6 +203,16 @@ struct dns_bind_ip {
 	const char *group;
 };
 
+struct dns_qtype_soa_list {
+	struct hlist_node node;
+	uint32_t qtypeid;
+};
+
+struct dns_qtype_soa_table {
+	DECLARE_HASHTABLE(qtype, 8);
+};
+extern struct dns_qtype_soa_table dns_qtype_soa_table;
+
 extern struct dns_bind_ip dns_conf_bind_ip[DNS_MAX_BIND_IP];
 extern int dns_conf_bind_ip_num;
 

src/dns_server.c

@@ -2328,6 +2328,25 @@ errout:
 	return -1;
 }
 
+static int _dns_server_qtype_soa(struct dns_request *request)
+{
+	struct dns_qtype_soa_list *soa_list = NULL;
+
+	uint32_t key = hash_32_generic(request->qtype, 32);
+	hash_for_each_possible(dns_qtype_soa_table.qtype, soa_list, node, key)
+	{
+		if (request->qtype != soa_list->qtypeid) {
+			continue;
+		}
+
+		_dns_server_reply_SOA(DNS_RC_NOERROR, request);
+		tlog(TLOG_DEBUG, "force qtype %d soa", request->qtype);
+		return 0;
+	}
+
+	return -1;
+}
+
 static void _dns_server_process_speed_check_rule(struct dns_request *request)
 {
 	struct dns_domain_check_order *check_order = NULL;
@@ -2351,7 +2370,6 @@ static int _dns_server_get_expired_ttl_reply(struct dns_cache *dns_cache)
 	return dns_conf_serve_expired_reply_ttl;
 }
 
-
 static int _dns_server_get_expired_cname_ttl_reply(struct dns_cache *dns_cache)
 {
 	int ttl = dns_cache_get_cname_ttl(dns_cache);
@@ -2429,13 +2447,12 @@ static int _dns_server_process_cache_packet(struct dns_request *request, struct
 	}
 
 	_dns_server_get_answer(request, packet);
-	
+
 	_dns_server_audit_log(request);
 	if (request->result_callback) {
 		_dns_result_callback(request);
 	}
 
-
 	if (request->conn == NULL) {
 		return 0;
 	}
@@ -2703,6 +2720,11 @@ static int _dns_server_do_query(struct dns_request *request, const char *domain,
 		goto clean_exit;
 	}
 
+	/* process qtype soa */
+	if (_dns_server_qtype_soa(request) == 0) {
+		goto clean_exit;
+	}
+
 	/* process speed check rule */
 	_dns_server_process_speed_check_rule(request);