dns_server: cache ptr record

src/dns_server.c

@@ -953,7 +953,7 @@ static int _dns_add_rrs(struct dns_server_post_context *context)
 	char *domain = request->domain;
 	if (request->has_ptr) {
 		/* add PTR record */
-		ret = dns_add_PTR(context->packet, DNS_RRS_AN, request->domain, 30, request->ptr_hostname);
+		ret = dns_add_PTR(context->packet, DNS_RRS_AN, request->domain, request->ip_ttl, request->ptr_hostname);
 	}
 
 	/* add CNAME record */
@@ -1258,6 +1258,22 @@ static inline int _dns_server_expired_cache_ttl(struct dns_cache *cache)
 	return cache->info.insert_time + cache->info.ttl + dns_conf_serve_expired_ttl - time(NULL);
 }
 
+static int _dns_cache_is_specify_packet(int qtype)
+{
+	switch (qtype) {
+	case DNS_T_PTR:
+	case DNS_T_HTTPS:
+	case DNS_T_TXT:
+	case DNS_T_SRV:
+		break;
+	default:
+		return -1;
+		break;
+	}
+
+	return 0;
+}
+
 static int _dns_server_get_cache_timeout(struct dns_request *request, struct dns_cache_key *cache_key, int ttl)
 {
 	int timeout = 0;
@@ -1266,7 +1282,7 @@ static int _dns_server_get_cache_timeout(struct dns_request *request, struct dns
 		return ttl + 1;
 	}
 
-	if (dns_conf_prefetch) {
+	if (dns_conf_prefetch && _dns_cache_is_specify_packet(request->qtype) != 0) {
 		if (dns_conf_serve_expired) {
 			timeout = dns_conf_serve_expired_prefetch_time;
 			if (timeout == 0) {
@@ -1514,15 +1530,15 @@ static int _dns_cache_packet(struct dns_server_post_context *context)
 	cache_key.query_flag = request->server_flags;
 
 	if (request->prefetch) {
-		if (dns_cache_replace(&cache_key, request->rcode, context->reply_ttl, -1,
+		if (dns_cache_replace(&cache_key, request->rcode, request->ip_ttl, -1,
-							  _dns_server_get_cache_timeout(request, &cache_key, context->reply_ttl),
+							  _dns_server_get_cache_timeout(request, &cache_key, request->ip_ttl),
 							  !request->prefetch_expired_domain, cache_packet) != 0) {
 			goto errout;
 		}
 	} else {
 		/* insert result to cache */
-		if (dns_cache_insert(&cache_key, request->rcode, context->reply_ttl, -1,
+		if (dns_cache_insert(&cache_key, request->rcode, request->ip_ttl, -1,
-							 _dns_server_get_cache_timeout(request, NULL, context->reply_ttl), cache_packet) != 0) {
+							 _dns_server_get_cache_timeout(request, NULL, request->ip_ttl), cache_packet) != 0) {
 			goto errout;
 		}
 	}
@@ -1585,15 +1601,8 @@ static int _dns_result_callback(struct dns_server_post_context *context)
 
 static int _dns_cache_specify_packet(struct dns_server_post_context *context)
 {
-	switch (context->qtype) {
+	if (_dns_cache_is_specify_packet(context->qtype) != 0) {
-	case DNS_T_PTR:
-	case DNS_T_HTTPS:
-	case DNS_T_TXT:
-	case DNS_T_SRV:
-		break;
-	default:
 		return 0;
-		break;
 	}
 
 	return _dns_cache_packet(context);
@@ -3969,6 +3978,50 @@ errout:
 	return -1;
 }
 
+static int _dns_server_get_local_ttl(struct dns_request *request)
+{
+	struct dns_ttl_rule *ttl_rule;
+
+	/* get domain rule flag */
+	ttl_rule = _dns_server_get_dns_rule(request, DOMAIN_RULE_TTL);
+	if (ttl_rule != NULL) {
+		if (ttl_rule->ttl > 0) {
+			return ttl_rule->ttl;
+		}
+	}
+
+	if (dns_conf_local_ttl > 0) {
+		return dns_conf_local_ttl;
+	}
+
+	if (dns_conf_rr_ttl > 0) {
+		return dns_conf_rr_ttl;
+	}
+
+	if (dns_conf_rr_ttl_min > 0) {
+		return dns_conf_rr_ttl_min;
+	}
+
+	return DNS_SERVER_ADDR_TTL;
+}
+
+static int _dns_server_process_private_ptr(struct dns_request *request)
+{
+	int a, b, c, d;
+	int ret = sscanf(request->domain, "%d.%d.%d.%d.in-addr.arpa", &a, &b, &c, &d);
+	if (ret != 4) {
+		return -1;
+	}
+
+	if (d == 10 || (d == 172 && c >= 16 && c <= 31) || (d == 192 && c == 168)) {
+		request->has_soa = 1;
+		_dns_server_setup_soa(request);
+		return 0;
+	}
+
+	return -1;
+}
+
 static int _dns_server_process_ptr(struct dns_request *request)
 {
 	if (_dns_server_process_ptrs(request) == 0) {
@@ -3979,14 +4032,20 @@ static int _dns_server_process_ptr(struct dns_request *request)
 		goto reply_exit;
 	}
 
+	if (_dns_server_process_private_ptr(request) == 0) {
+		goto reply_exit;
+	}
+
 	return -1;
 
 reply_exit:
 	request->rcode = DNS_RC_NOERROR;
+	request->ip_ttl = _dns_server_get_local_ttl(request);
 	struct dns_server_post_context context;
 	_dns_server_post_context_init(&context, request);
 	context.do_reply = 1;
 	context.do_audit = 0;
+	context.do_cache = 1;
 	_dns_request_post(&context);
 	return 0;
 }
@@ -4275,33 +4334,6 @@ soa:
 	return 0;
 }
 
-static int _dns_server_get_local_ttl(struct dns_request *request)
-{
-	struct dns_ttl_rule *ttl_rule;
-
-	/* get domain rule flag */
-	ttl_rule = _dns_server_get_dns_rule(request, DOMAIN_RULE_TTL);
-	if (ttl_rule != NULL) {
-		if (ttl_rule->ttl > 0) {
-			return ttl_rule->ttl;
-		}
-	}
-
-	if (dns_conf_local_ttl > 0) {
-		return dns_conf_local_ttl;
-	}
-
-	if (dns_conf_rr_ttl > 0) {
-		return dns_conf_rr_ttl;
-	}
-
-	if (dns_conf_rr_ttl_min > 0) {
-		return dns_conf_rr_ttl_min;
-	}
-
-	return DNS_SERVER_ADDR_TTL;
-}
-
 static int _dns_server_address_generate_order(int orders[], int order_num, int max_order_count)
 {
 	int i = 0;
@@ -4918,6 +4950,10 @@ static int _dns_server_process_cache(struct dns_request *request)
 		goto reply_cache;
 	}
 
+	if (request->qtype != DNS_T_A && request->qtype != DNS_T_AAAA) {
+		goto reply_cache;
+	}
+
 	if (request->dualstack_selection) {
 		int dualstack_qtype = 0;
 		if (request->qtype == DNS_T_A) {
@@ -4925,7 +4961,7 @@ static int _dns_server_process_cache(struct dns_request *request)
 		} else if (request->qtype == DNS_T_AAAA) {
 			dualstack_qtype = DNS_T_A;
 		} else {
-			goto out;
+			goto reply_cache;
 		}
 
 		cache_key.qtype = dualstack_qtype;
@@ -5114,20 +5150,26 @@ static int _dns_server_process_smartdns_domain(struct dns_request *request)
 	return _dns_server_reply_request_eth_ip(request);
 }
 
+static int _dns_server_process_ptr_query(struct dns_request *request)
+{
+	if (request->qtype != DNS_T_PTR) {
+		return -1;
+	}
+
+	if (_dns_server_process_ptr(request) == 0) {
+		return 0;
+	}
+
+	request->passthrough = 1;
+	return -1;
+}
+
 static int _dns_server_process_special_query(struct dns_request *request)
 {
 	int ret = 0;
 
 	switch (request->qtype) {
 	case DNS_T_PTR:
-		/* return PTR record */
-		ret = _dns_server_process_ptr(request);
-		if (ret == 0) {
-			goto clean_exit;
-		} else {
-			/* pass to upstream server */
-			request->passthrough = 1;
-		}
 		break;
 	case DNS_T_SVCB:
 		ret = _dns_server_process_srv(request);
@@ -5141,7 +5183,6 @@ static int _dns_server_process_special_query(struct dns_request *request)
 	case DNS_T_A:
 		break;
 	case DNS_T_AAAA:
-
 		break;
 	default:
 		tlog(TLOG_DEBUG, "unsupported qtype: %d, domain: %s", request->qtype, request->domain);
@@ -5400,6 +5441,11 @@ static int _dns_server_do_query(struct dns_request *request, int skip_notify_eve
 		}
 	}
 
+	/* process ptr */
+	if (_dns_server_process_ptr_query(request) == 0) {
+		goto clean_exit;
+	}
+
 	ret = _dns_server_set_to_pending_list(request);
 	if (ret == 0) {
 		goto clean_exit;
@@ -6467,7 +6513,7 @@ static int _dns_server_cache_expired(struct dns_cache *dns_cache)
 		return -1;
 	}
 
-	if (dns_conf_prefetch == 1) {
+	if (dns_conf_prefetch == 1 && _dns_cache_is_specify_packet(dns_cache->info.qtype) != 0) {
 		if (dns_conf_serve_expired == 1) {
 			return _dns_server_prefetch_expired_domain(dns_cache);
 		} else {