address: support multiple ip addresses

etc/smartdns/smartdns.conf

@@ -247,8 +247,9 @@ log-level info
 # expand-ptr-from-address yes
 
 # specific address to domain
-# address /domain/[ip|-|-4|-6|#|#4|#6]
+# address /domain/[ip1,ip2|-|-4|-6|#|#4|#6]
 # address /www.example.com/1.2.3.4, return ip 1.2.3.4 to client
+# address /www.example.com/1.2.3.4,5.6.7.8, return multiple ip addresses
 # address /www.example.com/-, ignore address, query from upstream, suffix 4, for ipv4, 6 for ipv6, none for all
 # address /www.example.com/#, return SOA to client, suffix 4, for ipv4, 6 for ipv6, none for all
 

src/dns_conf.c

@@ -30,7 +30,7 @@
 #include <syslog.h>
 #include <unistd.h>
 
-#define DNS_MAX_REPLY_IP_NUM 8
+#define TMP_BUFF_LEN 1024
 
 /* ipset */
 struct dns_ipset_table {
@@ -173,7 +173,7 @@ static int _conf_ptr_add(const char *hostname, const char *ip, int is_dynamic);
 static int _conf_client_subnet(char *subnet, struct dns_edns_client_subnet *ipv4_ecs,
 							   struct dns_edns_client_subnet *ipv6_ecs);
 
-static void *_new_dns_rule(enum domain_rule domain_rule)
+static void *_new_dns_rule_ext(enum domain_rule domain_rule, int ext_size)
 {
 	struct dns_rule *rule;
 	int size = 0;
@@ -220,6 +220,7 @@ static void *_new_dns_rule(enum domain_rule domain_rule)
 		return NULL;
 	}
 
+	size += ext_size;
 	rule = malloc(size);
 	if (!rule) {
 		return NULL;
@@ -230,6 +231,11 @@ static void *_new_dns_rule(enum domain_rule domain_rule)
 	return rule;
 }
 
+static void *_new_dns_rule(enum domain_rule domain_rule)
+{
+	return _new_dns_rule_ext(domain_rule, 0);
+}
+
 static void _dns_rule_get(struct dns_rule *rule)
 {
 	atomic_inc(&rule->refcnt);
@@ -1498,50 +1504,75 @@ static int _conf_domain_rule_address(char *domain, const char *domain_address)
 	struct dns_rule_address_IPV4 *address_ipv4 = NULL;
 	struct dns_rule_address_IPV6 *address_ipv6 = NULL;
 	struct dns_rule *address = NULL;
+
 	char ip[MAX_IP_LEN];
 	int port = 0;
 	struct sockaddr_storage addr;
 	socklen_t addr_len = sizeof(addr);
-	enum domain_rule type = 0;
 	unsigned int flag = 0;
+	char *ptr = NULL;
+	char *field = NULL;
+	char tmpbuff[TMP_BUFF_LEN] = {0};
 
-	if (*(domain_address) == '#') {
-		if (strncmp(domain_address, "#4", sizeof("#4")) == 0) {
-			flag = DOMAIN_FLAG_ADDR_IPV4_SOA;
-		} else if (strncmp(domain_address, "#6", sizeof("#6")) == 0) {
-			flag = DOMAIN_FLAG_ADDR_IPV6_SOA;
-		} else if (strncmp(domain_address, "#", sizeof("#")) == 0) {
-			flag = DOMAIN_FLAG_ADDR_SOA;
-		} else {
-			goto errout;
-		}
+	char ipv6_addr[DNS_MAX_REPLY_IP_NUM][DNS_RR_AAAA_LEN];
+	int ipv6_num = 0;
+	char ipv4_addr[DNS_MAX_REPLY_IP_NUM][DNS_RR_A_LEN];
+	int ipv4_num = 0;
 
-		/* add SOA rule */
-		if (_config_domain_rule_flag_set(domain, flag, 0) != 0) {
-			goto errout;
+	safe_strncpy(tmpbuff, domain_address, sizeof(tmpbuff));
+
+	ptr = tmpbuff;
+
+	do {
+		field = ptr;
+		ptr = strstr(ptr, ",");
+
+		if (field == NULL) {
+			break;
 		}
 
-		return 0;
-	} else if (*(domain_address) == '-') {
-		if (strncmp(domain_address, "-4", sizeof("-4")) == 0) {
-			flag = DOMAIN_FLAG_ADDR_IPV4_IGN;
-		} else if (strncmp(domain_address, "-6", sizeof("-6")) == 0) {
-			flag = DOMAIN_FLAG_ADDR_IPV6_IGN;
-		} else if (strncmp(domain_address, "-", sizeof("-")) == 0) {
-			flag = DOMAIN_FLAG_ADDR_IGN;
-		} else {
-			goto errout;
+		if (ptr) {
+			*ptr = 0;
 		}
 
-		/* ignore rule */
-		if (_config_domain_rule_flag_set(domain, flag, 0) != 0) {
-			goto errout;
+		if (*(field) == '#') {
+			if (strncmp(field, "#4", sizeof("#4")) == 0) {
+				flag = DOMAIN_FLAG_ADDR_IPV4_SOA;
+			} else if (strncmp(field, "#6", sizeof("#6")) == 0) {
+				flag = DOMAIN_FLAG_ADDR_IPV6_SOA;
+			} else if (strncmp(field, "#", sizeof("#")) == 0) {
+				flag = DOMAIN_FLAG_ADDR_SOA;
+			} else {
+				goto errout;
+			}
+
+			/* add SOA rule */
+			if (_config_domain_rule_flag_set(domain, flag, 0) != 0) {
+				goto errout;
+			}
+
+			continue;
+		} else if (*(field) == '-') {
+			if (strncmp(field, "-4", sizeof("-4")) == 0) {
+				flag = DOMAIN_FLAG_ADDR_IPV4_IGN;
+			} else if (strncmp(field, "-6", sizeof("-6")) == 0) {
+				flag = DOMAIN_FLAG_ADDR_IPV6_IGN;
+			} else if (strncmp(field, "-", sizeof("-")) == 0) {
+				flag = DOMAIN_FLAG_ADDR_IGN;
+			} else {
+				goto errout;
+			}
+
+			/* ignore rule */
+			if (_config_domain_rule_flag_set(domain, flag, 0) != 0) {
+				goto errout;
+			}
+
+			continue;
 		}
 
-		return 0;
-	} else {
 		/* set address to domain */
-		if (parse_ip(domain_address, ip, &port) != 0) {
+		if (parse_ip(field, ip, &port) != 0) {
 			goto errout;
 		}
 
@@ -1552,53 +1583,74 @@ static int _conf_domain_rule_address(char *domain, const char *domain_address)
 		switch (addr.ss_family) {
 		case AF_INET: {
 			struct sockaddr_in *addr_in = NULL;
-			address_ipv4 = _new_dns_rule(DOMAIN_RULE_ADDRESS_IPV4);
-			if (address_ipv4 == NULL) {
-				goto errout;
-			}
-
 			addr_in = (struct sockaddr_in *)&addr;
-			memcpy(address_ipv4->ipv4_addr, &addr_in->sin_addr.s_addr, 4);
-			type = DOMAIN_RULE_ADDRESS_IPV4;
-			address = (struct dns_rule *)address_ipv4;
+			memcpy(ipv4_addr[ipv4_num], &addr_in->sin_addr.s_addr, DNS_RR_A_LEN);
+			ipv4_num++;
 		} break;
 		case AF_INET6: {
 			struct sockaddr_in6 *addr_in6 = NULL;
 			addr_in6 = (struct sockaddr_in6 *)&addr;
 			if (IN6_IS_ADDR_V4MAPPED(&addr_in6->sin6_addr)) {
-				address_ipv4 = _new_dns_rule(DOMAIN_RULE_ADDRESS_IPV4);
-				if (address_ipv4 == NULL) {
-					goto errout;
-				}
-				memcpy(address_ipv4->ipv4_addr, addr_in6->sin6_addr.s6_addr + 12, 4);
-				type = DOMAIN_RULE_ADDRESS_IPV4;
-				address = (struct dns_rule *)address_ipv4;
+				memcpy(ipv4_addr[ipv4_num], addr_in6->sin6_addr.s6_addr + 12, DNS_RR_A_LEN);
+				ipv4_num++;
 			} else {
 				address_ipv6 = _new_dns_rule(DOMAIN_RULE_ADDRESS_IPV6);
 				if (address_ipv6 == NULL) {
 					goto errout;
 				}
-				memcpy(address_ipv6->ipv6_addr, addr_in6->sin6_addr.s6_addr, 16);
-				type = DOMAIN_RULE_ADDRESS_IPV6;
-				address = (struct dns_rule *)address_ipv6;
+				memcpy(ipv6_addr[ipv6_num], addr_in6->sin6_addr.s6_addr, DNS_RR_AAAA_LEN);
+				ipv6_num++;
 			}
 		} break;
 		default:
-			goto errout;
+			ip[0] = '\0';
+			break;
 		}
 
 		/* add PTR */
-		if (dns_conf_expand_ptr_from_address == 1 && _conf_ptr_add(domain, ip, 0) != 0) {
+		if (dns_conf_expand_ptr_from_address == 1 && ip[0] != '\0' && _conf_ptr_add(domain, ip, 0) != 0) {
 			goto errout;
 		}
+
+		if (ptr) {
+			ptr++;
+		}
+	} while (ptr);
+
+	if (ipv4_num > 0) {
+		address_ipv4 = _new_dns_rule_ext(DOMAIN_RULE_ADDRESS_IPV4, ipv4_num * DNS_RR_A_LEN);
+		if (address_ipv4 == NULL) {
+			goto errout;
+		}
+
+		memcpy(address_ipv4->ipv4_addr, ipv4_addr[0], ipv4_num * DNS_RR_A_LEN);
+		address_ipv4->addr_num = ipv4_num;
+		address = (struct dns_rule *)address_ipv4;
+
+		if (_config_domain_rule_add(domain, DOMAIN_RULE_ADDRESS_IPV4, address) != 0) {
+			goto errout;
+		}
+
+		_dns_rule_put(address);
 	}
 
-	/* add domain to ART-tree */
-	if (_config_domain_rule_add(domain, type, address) != 0) {
-		goto errout;
+	if (ipv6_num > 0) {
+		address_ipv6 = _new_dns_rule_ext(DOMAIN_RULE_ADDRESS_IPV6, ipv6_num * DNS_RR_AAAA_LEN);
+		if (address_ipv6 == NULL) {
+			goto errout;
+		}
+
+		memcpy(address_ipv6->ipv6_addr, ipv6_addr[0], ipv6_num * DNS_RR_AAAA_LEN);
+		address_ipv6->addr_num = ipv6_num;
+		address = (struct dns_rule *)address_ipv6;
+
+		if (_config_domain_rule_add(domain, DOMAIN_RULE_ADDRESS_IPV6, address) != 0) {
+			goto errout;
+		}
+
+		_dns_rule_put(address);
 	}
 
-	_dns_rule_put(address);
 	return 0;
 errout:
 	if (address) {

src/dns_conf.h

@@ -58,6 +58,7 @@ extern "C" {
 #define DEFAULT_DNS_HTTPS_PORT 443
 #define DNS_MAX_CONF_CNAME_LEN 256
 #define MAX_QTYPE_NUM 65535
+#define DNS_MAX_REPLY_IP_NUM 8
 
 #define SMARTDNS_CONF_FILE "/etc/smartdns/smartdns.conf"
 #define SMARTDNS_LOG_FILE "/var/log/smartdns/smartdns.log"
@@ -150,12 +151,14 @@ struct dns_rule_flags {
 
 struct dns_rule_address_IPV4 {
 	struct dns_rule head;
-	unsigned char ipv4_addr[DNS_RR_A_LEN];
+	char addr_num;
+	unsigned char ipv4_addr[][DNS_RR_A_LEN];
 };
 
 struct dns_rule_address_IPV6 {
 	struct dns_rule head;
-	unsigned char ipv6_addr[DNS_RR_AAAA_LEN];
+	char addr_num;
+	unsigned char ipv6_addr[][DNS_RR_AAAA_LEN];
 };
 
 struct dns_ipset_name {

src/dns_server.c

@@ -4110,10 +4110,35 @@ static int _dns_server_get_local_ttl(struct dns_request *request)
 	return DNS_SERVER_ADDR_TTL;
 }
 
+static int _dns_server_address_generate_order(int orders[], int order_num, int max_order_count)
+{
+	int i = 0;
+	int j = 0;
+	int k = 0;
+	for (i = 0; i < order_num && i < max_order_count; i++) {
+		orders[i] = i;
+	}
+
+	for (i = 0; i < order_num && max_order_count; i++) {
+		k = rand() % order_num;
+		j = rand() % order_num;
+		if (j == k) {
+			continue;
+		}
+
+		int temp = orders[j];
+		orders[j] = orders[k];
+		orders[k] = temp;
+	}
+
+	return 0;
+}
+
 static int _dns_server_process_address(struct dns_request *request)
 {
 	struct dns_rule_address_IPV4 *address_ipv4 = NULL;
 	struct dns_rule_address_IPV6 *address_ipv6 = NULL;
+	int orders[DNS_MAX_REPLY_IP_NUM];
 
 	if (_dns_server_has_bind_flag(request, BIND_FLAG_NO_RULE_ADDR) == 0) {
 		goto errout;
@@ -4126,14 +4151,39 @@ static int _dns_server_process_address(struct dns_request *request)
 			goto errout;
 		}
 		address_ipv4 = _dns_server_get_dns_rule(request, DOMAIN_RULE_ADDRESS_IPV4);
-		memcpy(request->ip_addr, address_ipv4->ipv4_addr, DNS_RR_A_LEN);
+		if (address_ipv4 == NULL) {
+			goto errout;
+		}
+		_dns_server_address_generate_order(orders, address_ipv4->addr_num, DNS_MAX_REPLY_IP_NUM);
+
+		memcpy(request->ip_addr, address_ipv4->ipv4_addr[orders[0]], DNS_RR_A_LEN);
+		for (int i = 1; i < address_ipv4->addr_num; i++) {
+			int index = orders[i];
+			if (index >= address_ipv4->addr_num) {
+				continue;
+			}
+			_dns_ip_address_check_add(request, request->cname, address_ipv4->ipv4_addr[index], DNS_T_A, 1, NULL);
+		}
 		break;
 	case DNS_T_AAAA:
 		if (request->domain_rule.rules[DOMAIN_RULE_ADDRESS_IPV6] == NULL) {
 			goto errout;
 		}
+
 		address_ipv6 = _dns_server_get_dns_rule(request, DOMAIN_RULE_ADDRESS_IPV6);
-		memcpy(request->ip_addr, address_ipv6->ipv6_addr, DNS_RR_AAAA_LEN);
+		if (address_ipv6 == NULL) {
+			goto errout;
+		}
+		_dns_server_address_generate_order(orders, address_ipv6->addr_num, DNS_MAX_REPLY_IP_NUM);
+
+		memcpy(request->ip_addr, address_ipv6->ipv6_addr[orders[0]], DNS_RR_AAAA_LEN);
+		for (int i = 1; i < address_ipv6->addr_num; i++) {
+			int index = orders[i];
+			if (index >= address_ipv6->addr_num) {
+				continue;
+			}
+			_dns_ip_address_check_add(request, request->cname, address_ipv6->ipv6_addr[index], DNS_T_AAAA, 1, NULL);
+		}
 		break;
 	default:
 		goto errout;
@@ -4149,6 +4199,7 @@ static int _dns_server_process_address(struct dns_request *request)
 	context.do_reply = 1;
 	context.do_audit = 1;
 	context.do_ipset = 1;
+	context.select_all_best_ip = 1;
 	_dns_request_post(&context);
 
 	return 0;

test/cases/test-address.cc

@@ -161,3 +161,94 @@ cache-persist no)""");
 	EXPECT_EQ(client.GetAnswer()[0].GetType(), "AAAA");
 	EXPECT_EQ(client.GetAnswer()[0].GetData(), "64:ff9b::1010:1010");
 }
+
+TEST_F(Address, multiaddress)
+{
+	smartdns::MockServer server_upstream;
+	smartdns::Server server;
+
+	server_upstream.Start("udp://0.0.0.0:61053", [&](struct smartdns::ServerRequestContext *request) {
+		if (request->qtype == DNS_T_A) {
+			smartdns::MockServer::AddIP(request, request->domain.c_str(), "1.2.3.4", 700);
+			return smartdns::SERVER_REQUEST_OK;
+		} else if (request->qtype == DNS_T_AAAA) {
+			smartdns::MockServer::AddIP(request, request->domain.c_str(), "64:ff9b::102:304", 700);
+			return smartdns::SERVER_REQUEST_OK;
+		}
+		return smartdns::SERVER_REQUEST_SOA;
+	});
+
+	server.Start(R"""(bind [::]:60053
+server 127.0.0.1:61053
+log-num 0
+log-console yes
+log-level debug
+speed-check-mode none
+address /a.com/10.10.10.10,11.11.11.11,22.22.22.22
+address /a.com/64:ff9b::1010:1010,64:ff9b::1111:1111,64:ff9b::2222:2222
+cache-persist no)""");
+	smartdns::Client client;
+	ASSERT_TRUE(client.Query("a.com A", 60053));
+	std::cout << client.GetResult() << std::endl;
+	std::map<std::string, smartdns::DNSRecord *> result;
+
+	ASSERT_EQ(client.GetAnswerNum(), 3);
+	EXPECT_EQ(client.GetStatus(), "NOERROR");
+	auto answers = client.GetAnswer();
+	for (int i = 0; i < client.GetAnswerNum(); i++) {
+		result[client.GetAnswer()[i].GetData()] = &answers[i];
+	}
+
+	ASSERT_NE(result.find("10.10.10.10"), result.end());
+	auto check_result = result["10.10.10.10"];
+	EXPECT_EQ(check_result->GetName(), "a.com");
+	EXPECT_EQ(check_result->GetTTL(), 600);
+	EXPECT_EQ(check_result->GetType(), "A");
+	EXPECT_EQ(check_result->GetData(), "10.10.10.10");
+
+	ASSERT_NE(result.find("11.11.11.11"), result.end());
+	check_result = result["11.11.11.11"];
+	EXPECT_EQ(check_result->GetName(), "a.com");
+	EXPECT_EQ(check_result->GetTTL(), 600);
+	EXPECT_EQ(check_result->GetType(), "A");
+	EXPECT_EQ(check_result->GetData(), "11.11.11.11");
+
+	ASSERT_NE(result.find("22.22.22.22"), result.end());
+	check_result = result["22.22.22.22"];
+	EXPECT_EQ(check_result->GetName(), "a.com");
+	EXPECT_EQ(check_result->GetTTL(), 600);
+	EXPECT_EQ(check_result->GetType(), "A");
+	EXPECT_EQ(check_result->GetData(), "22.22.22.22");
+
+	result.clear();
+
+	ASSERT_TRUE(client.Query("a.com AAAA", 60053));
+	std::cout << client.GetResult() << std::endl;
+	ASSERT_EQ(client.GetAnswerNum(), 3);
+	EXPECT_EQ(client.GetStatus(), "NOERROR");
+	answers = client.GetAnswer();
+	for (int i = 0; i < client.GetAnswerNum(); i++) {
+		result[client.GetAnswer()[i].GetData()] = &answers[i];
+	}
+
+	ASSERT_NE(result.find("64:ff9b::1010:1010"), result.end());
+	check_result = result["64:ff9b::1010:1010"];
+	EXPECT_EQ(check_result->GetName(), "a.com");
+	EXPECT_EQ(check_result->GetTTL(), 600);
+	EXPECT_EQ(check_result->GetType(), "AAAA");
+	EXPECT_EQ(check_result->GetData(), "64:ff9b::1010:1010");
+
+	ASSERT_NE(result.find("64:ff9b::1111:1111"), result.end());
+	check_result = result["64:ff9b::1111:1111"];
+	EXPECT_EQ(check_result->GetName(), "a.com");
+	EXPECT_EQ(check_result->GetTTL(), 600);
+	EXPECT_EQ(check_result->GetType(), "AAAA");
+	EXPECT_EQ(check_result->GetData(), "64:ff9b::1111:1111");
+
+	ASSERT_NE(result.find("64:ff9b::2222:2222"), result.end());
+	check_result = result["64:ff9b::2222:2222"];
+	EXPECT_EQ(check_result->GetName(), "a.com");
+	EXPECT_EQ(check_result->GetTTL(), 600);
+	EXPECT_EQ(check_result->GetType(), "AAAA");
+	EXPECT_EQ(check_result->GetData(), "64:ff9b::2222:2222");
+}