Update code

dns.c

@@ -35,10 +35,10 @@ short dns_read_short(unsigned char **buffer)
 {
 	unsigned short value;
 
-	value = *((unsigned short *)(*buffer));
+	value = ntohs(*((unsigned short *)(*buffer)));
 	*buffer += 2;
 
-	return ntohs(value);
+	return value;
 }
 
 void dns_write_char(unsigned char **buffer, unsigned char value)
@@ -63,7 +63,7 @@ void dns_write_short(unsigned char **buffer, unsigned short value)
 
 void dns_write_int(unsigned char **buffer, unsigned int value)
 {
-	value = htons(value);
+	value = htonl(value);
 	*((unsigned int *)(*buffer)) = value;
 	*buffer += 4;
 }
@@ -72,10 +72,10 @@ unsigned int dns_read_int(unsigned char **buffer)
 {
 	unsigned int value;
 
-	value = *((unsigned int *)(*buffer));
+	value = ntohl(*((unsigned int *)(*buffer)));
 	*buffer += 4;
 
-	return ntohs(value);
+	return value;
 }
 
 struct dns_rrs *dns_get_rrs_start(struct dns_packet *packet, dns_rr_type type, int *count)

dns_client.c

@@ -50,54 +50,66 @@
 #define DNS_HOSTNAME_LEN 128
 
 struct dns_query_server {
-	int fd;
-	int type;
-	char host[DNS_HOSTNAME_LEN];
-	struct list_head list;
+    int fd;
+    int type;
+    char host[DNS_HOSTNAME_LEN];
+    struct list_head list;
 };
 
 struct dns_client {
-	pthread_t tid;
-	int run;
-	int epoll_fd;
+    pthread_t tid;
+    int run;
+    int epoll_fd;
 
-	pthread_mutex_t server_list_lock;
-	struct list_head dns_server_list;
+    pthread_mutex_t server_list_lock;
+    struct list_head dns_server_list;
 
-	pthread_mutex_t dns_request_lock;
-	struct list_head dns_request_list;
-	struct list_head dns_request_wait_list;
+    pthread_mutex_t dns_request_lock;
+    struct list_head dns_request_list;
+    struct list_head dns_request_wait_list;
 
-	pthread_mutex_t domain_map_lock;
-	DECLARE_HASHTABLE(domain_map, 6);
+    pthread_mutex_t domain_map_lock;
+    DECLARE_HASHTABLE(domain_map, 6);
 
-	int udp;
+    int udp;
 };
 
 struct dns_server_info {
-	struct list_head list;
-	struct ping_host_struct *ping_host;
-	dns_server_type_t type;
-	unsigned short ss_family;
-	socklen_t addr_len;
-	union {
-		struct sockaddr_in in;
-		struct sockaddr_in6 in6;
-		struct sockaddr addr;
-	};
+    struct list_head list;
+    struct ping_host_struct *ping_host;
+    dns_server_type_t type;
+    unsigned short ss_family;
+    socklen_t addr_len;
+    union {
+        struct sockaddr_in in;
+        struct sockaddr_in6 in6;
+        struct sockaddr addr;
+    };
+};
+
+struct dns_query_replied {
+    struct hlist_node node;
+    socklen_t addr_len;
+    union {
+        struct sockaddr_in in;
+        struct sockaddr_in6 in6;
+        struct sockaddr addr;
+    };
 };
 
 struct dns_query_struct {
-	atomic_t refcnt;
-	unsigned short sid;
-	struct list_head dns_request_list;
-	struct hlist_node domain_node;
-	char domain[DNS_MAX_CNAME_LEN];
-	int qtype;
-	atomic_t dns_request_sent;
-	void *user_ptr;
-	unsigned long send_tick;
-	dns_client_callback callback;
+    atomic_t refcnt;
+    unsigned short sid;
+    struct list_head dns_request_list;
+    struct hlist_node domain_node;
+    char domain[DNS_MAX_CNAME_LEN];
+    int qtype;
+    atomic_t dns_request_sent;
+    void *user_ptr;
+    unsigned long send_tick;
+    dns_client_callback callback;
+
+    DECLARE_HASHTABLE(replied_map, 4);
 };
 
 static struct dns_client client;
@@ -105,683 +117,727 @@ static atomic_t dns_client_sid = ATOMIC_INIT(0);
 
 static struct addrinfo *_dns_client_getaddr(const char *host, char *port, int type, int protocol)
 {
-	struct addrinfo hints;
-	struct addrinfo *result = NULL;
-	int ret = 0;
-
-	memset(&hints, 0, sizeof(hints));
-	hints.ai_family = AF_UNSPEC;
-	hints.ai_socktype = type;
-	hints.ai_protocol = protocol;
-
-	ret = getaddrinfo(host, port, &hints, &result);
-	if (ret != 0) {
-		tlog(TLOG_ERROR, "get addr info failed. %s\n", gai_strerror(errno));
-		tlog(TLOG_ERROR, "host = %s, port = %s, type = %d, protocol = %d", host, port, type, protocol);
-		goto errout;
-	}
-
-	return result;
+    struct addrinfo hints;
+    struct addrinfo *result = NULL;
+    int ret = 0;
+
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_family = AF_UNSPEC;
+    hints.ai_socktype = type;
+    hints.ai_protocol = protocol;
+
+    ret = getaddrinfo(host, port, &hints, &result);
+    if (ret != 0) {
+        tlog(TLOG_ERROR, "get addr info failed. %s\n", gai_strerror(errno));
+        tlog(TLOG_ERROR, "host = %s, port = %s, type = %d, protocol = %d", host, port, type, protocol);
+        goto errout;
+    }
+
+    return result;
 errout:
-	if (result) {
-		freeaddrinfo(result);
-	}
-	return NULL;
+    if (result) {
+        freeaddrinfo(result);
+    }
+    return NULL;
 }
 
 int _dns_client_server_exist(struct addrinfo *gai, dns_server_type_t server_type)
 {
-	struct dns_server_info *server_info, *tmp;
-	pthread_mutex_lock(&client.server_list_lock);
-	list_for_each_entry_safe(server_info, tmp, &client.dns_server_list, list)
-	{
-		if (server_info->addr_len != gai->ai_addrlen || server_info->ss_family != gai->ai_family) {
-			continue;
-		}
-
-		if (server_info->type != server_type) {
-			continue;
-		}
-
-		if (memcmp(&server_info->addr, gai->ai_addr, gai->ai_addrlen) != 0) {
-			continue;
-		}
-		pthread_mutex_lock(&client.server_list_lock);
-		return 0;
-	}
-	pthread_mutex_unlock(&client.server_list_lock);
-	return -1;
+    struct dns_server_info *server_info, *tmp;
+    pthread_mutex_lock(&client.server_list_lock);
+    list_for_each_entry_safe(server_info, tmp, &client.dns_server_list, list)
+    {
+        if (server_info->addr_len != gai->ai_addrlen || server_info->ss_family != gai->ai_family) {
+            continue;
+        }
+
+        if (server_info->type != server_type) {
+            continue;
+        }
+
+        if (memcmp(&server_info->addr, gai->ai_addr, gai->ai_addrlen) != 0) {
+            continue;
+        }
+        pthread_mutex_lock(&client.server_list_lock);
+        return 0;
+    }
+    pthread_mutex_unlock(&client.server_list_lock);
+    return -1;
 }
 
 int _dns_client_server_add(char *server_ip, struct addrinfo *gai, dns_server_type_t server_type)
 {
-	struct dns_server_info *server_info = NULL;
-
-	if (_dns_client_server_exist(gai, server_type) == 0) {
-		goto errout;
-	}
-
-	server_info = malloc(sizeof(*server_info));
-	if (server_info == NULL) {
-		goto errout;
-	}
-	memset(server_info, 0, sizeof(*server_info));
-	server_info->ss_family = gai->ai_family;
-	server_info->addr_len = gai->ai_addrlen;
-	server_info->type = server_type;
-	if (gai->ai_addrlen > sizeof(server_info->in6)) {
-		tlog(TLOG_ERROR, "addr len invalid, %d, %d, %d", gai->ai_addrlen, sizeof(server_info->addr), server_info->ss_family);
-		goto errout;
-	}
-	memcpy(&server_info->addr, gai->ai_addr, gai->ai_addrlen);
-
-	if (fast_ping_start(server_ip, 0, 60000, 1000, NULL, server_info) == NULL) {
-		goto errout;
-	}
-
-	pthread_mutex_lock(&client.server_list_lock);
-	list_add(&server_info->list, &client.dns_server_list);
-	pthread_mutex_unlock(&client.server_list_lock);
-	return 0;
+    struct dns_server_info *server_info = NULL;
+
+    if (_dns_client_server_exist(gai, server_type) == 0) {
+        goto errout;
+    }
+
+    server_info = malloc(sizeof(*server_info));
+    if (server_info == NULL) {
+        goto errout;
+    }
+    memset(server_info, 0, sizeof(*server_info));
+    server_info->ss_family = gai->ai_family;
+    server_info->addr_len = gai->ai_addrlen;
+    server_info->type = server_type;
+    if (gai->ai_addrlen > sizeof(server_info->in6)) {
+        tlog(TLOG_ERROR, "addr len invalid, %d, %d, %d", gai->ai_addrlen, sizeof(server_info->addr), server_info->ss_family);
+        goto errout;
+    }
+    memcpy(&server_info->addr, gai->ai_addr, gai->ai_addrlen);
+
+    if (fast_ping_start(server_ip, 0, 60000, 1000, NULL, server_info) == NULL) {
+        goto errout;
+    }
+
+    pthread_mutex_lock(&client.server_list_lock);
+    list_add(&server_info->list, &client.dns_server_list);
+    pthread_mutex_unlock(&client.server_list_lock);
+    return 0;
 errout:
-	if (server_info) {
-		free(server_info);
-	}
+    if (server_info) {
+        free(server_info);
+    }
 
-	return -1;
+    return -1;
 }
 
 int _dns_client_server_remove(char *server_ip, struct addrinfo *gai, dns_server_type_t server_type)
 {
-	struct dns_server_info *server_info, *tmp;
-	pthread_mutex_lock(&client.server_list_lock);
-	list_for_each_entry_safe(server_info, tmp, &client.dns_server_list, list)
-	{
-		if (server_info->addr_len != gai->ai_addrlen || server_info->ss_family != gai->ai_family) {
-			continue;
-		}
-
-		if (memcmp(&server_info->addr, gai->ai_addr, gai->ai_addrlen) != 0) {
-			continue;
-		}
-		list_del(&server_info->list);
-		pthread_mutex_unlock(&client.server_list_lock);
-		if (fast_ping_stop(server_info->ping_host) != 0) {
-			tlog(TLOG_ERROR, "stop ping failed.\n");
-		}
-		free(server_info);
-		return 0;
-	}
-	pthread_mutex_unlock(&client.server_list_lock);
-	return -1;
+    struct dns_server_info *server_info, *tmp;
+    pthread_mutex_lock(&client.server_list_lock);
+    list_for_each_entry_safe(server_info, tmp, &client.dns_server_list, list)
+    {
+        if (server_info->addr_len != gai->ai_addrlen || server_info->ss_family != gai->ai_family) {
+            continue;
+        }
+
+        if (memcmp(&server_info->addr, gai->ai_addr, gai->ai_addrlen) != 0) {
+            continue;
+        }
+        list_del(&server_info->list);
+        pthread_mutex_unlock(&client.server_list_lock);
+        if (fast_ping_stop(server_info->ping_host) != 0) {
+            tlog(TLOG_ERROR, "stop ping failed.\n");
+        }
+        free(server_info);
+        return 0;
+    }
+    pthread_mutex_unlock(&client.server_list_lock);
+    return -1;
 }
 
 int _dns_client_server_operate(char *server_ip, int port, dns_server_type_t server_type, int operate)
 {
-	char port_s[8];
-	int sock_type;
-	int ret;
-	struct addrinfo *gai = NULL;
-
-	if (server_type >= DNS_SERVER_TYPE_END) {
-		return -1;
-	}
-
-	if (server_type == DNS_SERVER_UDP) {
-		sock_type = SOCK_DGRAM;
-	} else {
-		sock_type = SOCK_STREAM;
-	}
-
-	snprintf(port_s, 8, "%d", port);
-	gai = _dns_client_getaddr(server_ip, port_s, sock_type, 0);
-	if (gai == NULL) {
-		tlog(TLOG_ERROR, "get address failed, %s:%d", server_ip, port);
-		goto errout;
-	}
-
-	if (operate == 0) {
-		ret = _dns_client_server_add(server_ip, gai, server_type);
-		if (ret != 0) {
-			goto errout;
-		}
-	} else {
-		ret = _dns_client_server_remove(server_ip, gai, server_type);
-		if (ret != 0) {
-			goto errout;
-		}
-	}
-	freeaddrinfo(gai);
-	return 0;
+    char port_s[8];
+    int sock_type;
+    int ret;
+    struct addrinfo *gai = NULL;
+
+    if (server_type >= DNS_SERVER_TYPE_END) {
+        return -1;
+    }
+
+    if (server_type == DNS_SERVER_UDP) {
+        sock_type = SOCK_DGRAM;
+    } else {
+        sock_type = SOCK_STREAM;
+    }
+
+    snprintf(port_s, 8, "%d", port);
+    gai = _dns_client_getaddr(server_ip, port_s, sock_type, 0);
+    if (gai == NULL) {
+        tlog(TLOG_ERROR, "get address failed, %s:%d", server_ip, port);
+        goto errout;
+    }
+
+    if (operate == 0) {
+        ret = _dns_client_server_add(server_ip, gai, server_type);
+        if (ret != 0) {
+            goto errout;
+        }
+    } else {
+        ret = _dns_client_server_remove(server_ip, gai, server_type);
+        if (ret != 0) {
+            goto errout;
+        }
+    }
+    freeaddrinfo(gai);
+    return 0;
 errout:
-	if (gai) {
-		freeaddrinfo(gai);
-	}
-	return -1;
+    if (gai) {
+        freeaddrinfo(gai);
+    }
+    return -1;
 }
 
 int dns_add_server(char *server_ip, int port, dns_server_type_t server_type)
 {
-	return _dns_client_server_operate(server_ip, port, server_type, 0);
+    return _dns_client_server_operate(server_ip, port, server_type, 0);
 }
 
 int dns_remove_server(char *server_ip, int port, dns_server_type_t server_type)
 {
-	return _dns_client_server_operate(server_ip, port, server_type, 1);
+    return _dns_client_server_operate(server_ip, port, server_type, 1);
 }
 
 void _dns_client_query_release(struct dns_query_struct *query)
 {
-	int refcnt = atomic_dec_return(&query->refcnt);
-	if (refcnt) {
-		if (refcnt < 0) {
-			tlog(TLOG_ERROR, "BUG: refcnt is %d", refcnt);
-			abort();
-		}
-		return;
-	}
-
-	if (query->callback) {
-		query->callback(query->domain, DNS_QUERY_END, NULL, NULL, 0, query->user_ptr);
+    int refcnt = atomic_dec_return(&query->refcnt);
+	int bucket = 0;
+	struct dns_query_replied *replied_map;
+	struct hlist_node *tmp;
+
+    if (refcnt) {
+        if (refcnt < 0) {
+            tlog(TLOG_ERROR, "BUG: refcnt is %d", refcnt);
+            abort();
+        }
+        return;
+    }
+
+    if (query->callback) {
+        query->callback(query->domain, DNS_QUERY_END, NULL, NULL, 0, query->user_ptr);
+    }
+
+	hash_for_each_safe(query->replied_map, bucket, tmp, replied_map, node)
+	{
+		hash_del(&replied_map->node);
+		free(replied_map);
 	}
-
-	memset(query, 0, sizeof(*query));
-	free(query);
+    memset(query, 0, sizeof(*query));
+    free(query);
 }
 
 void _dns_client_query_remove(struct dns_query_struct *query, int locked)
 {
-	if (locked == 0) {
-		pthread_mutex_lock(&client.domain_map_lock);
-		list_del_init(&query->dns_request_list);
-		hash_del(&query->domain_node);
-		pthread_mutex_unlock(&client.domain_map_lock);
-	} else {
-		list_del_init(&query->dns_request_list);
-		hash_del(&query->domain_node);
-	}
-
-	_dns_client_query_release(query);
+    if (locked == 0) {
+        pthread_mutex_lock(&client.domain_map_lock);
+        list_del_init(&query->dns_request_list);
+        hash_del(&query->domain_node);
+        pthread_mutex_unlock(&client.domain_map_lock);
+    } else {
+        list_del_init(&query->dns_request_list);
+        hash_del(&query->domain_node);
+    }
+
+    _dns_client_query_release(query);
 }
 
 void _dns_client_query_get(struct dns_query_struct *query)
 {
-	atomic_inc(&query->refcnt);
+    atomic_inc(&query->refcnt);
 }
 
 void _dns_client_period_run()
 {
-	struct dns_query_struct *query, *tmp;
-
-	unsigned long now = get_tick_count();
-	pthread_mutex_lock(&client.domain_map_lock);
-	list_for_each_entry_safe(query, tmp, &client.dns_request_list, dns_request_list)
-	{
-		if (now - query->send_tick >= 1000) {
-			_dns_client_query_remove(query, 1);
-		}
-	}
-	pthread_mutex_unlock(&client.domain_map_lock);
-	return;
+    struct dns_query_struct *query, *tmp;
+
+    unsigned long now = get_tick_count();
+    pthread_mutex_lock(&client.domain_map_lock);
+    list_for_each_entry_safe(query, tmp, &client.dns_request_list, dns_request_list)
+    {
+        if (now - query->send_tick >= 1000) {
+            _dns_client_query_remove(query, 1);
+        }
+    }
+    pthread_mutex_unlock(&client.domain_map_lock);
+    return;
 }
 
 static struct dns_query_struct *_dns_client_get_request(unsigned short sid, char *domain)
 {
-	struct dns_query_struct *query = NULL;
-	struct hlist_node *tmp = NULL;
-	unsigned int key;
-
-	key = hash_string(domain);
-	key = jhash(&sid, sizeof(sid), key);
-	pthread_mutex_lock(&client.domain_map_lock);
-	hash_for_each_possible_safe(client.domain_map, query, tmp, domain_node, key)
-	{
-		if (strncmp(query->domain, domain, DNS_MAX_CNAME_LEN) != 0) {
-			continue;
-		}
-		break;
-	}
-	pthread_mutex_unlock(&client.domain_map_lock);
-
-	return query;
+    struct dns_query_struct *query = NULL;
+    struct hlist_node *tmp = NULL;
+    unsigned int key;
+
+    key = hash_string(domain);
+    key = jhash(&sid, sizeof(sid), key);
+    pthread_mutex_lock(&client.domain_map_lock);
+    hash_for_each_possible_safe(client.domain_map, query, tmp, domain_node, key)
+    {
+        if (strncmp(query->domain, domain, DNS_MAX_CNAME_LEN) != 0) {
+            continue;
+        }
+        break;
+    }
+    pthread_mutex_unlock(&client.domain_map_lock);
+
+    return query;
 }
 
-static int _dns_client_recv(unsigned char *inpacket, int inpacket_len, struct sockaddr_storage *from, socklen_t from_len)
+int _dns_replied_check_add(struct dns_query_struct *dns_query, struct sockaddr *addr, socklen_t addr_len)
 {
-	int len;
-	int i;
-	int qtype;
-	int qclass;
-	char domain[DNS_MAX_CNAME_LEN];
-	int rr_count;
-	struct dns_rrs *rrs = NULL;
-	unsigned char packet_buff[DNS_PACKSIZE];
-	struct dns_packet *packet = (struct dns_packet *)packet_buff;
-	int ret = 0;
-	struct dns_query_struct *query;
-	int request_num = 0;
-
-	packet->head.tc = 0;
-	len = dns_decode(packet, DNS_PACKSIZE, inpacket, inpacket_len);
-	if (len != 0) {
-		tlog(TLOG_ERROR, "decode failed, packet len = %d, tc=%d, %d\n", inpacket_len, packet->head.tc, packet->head.id);
-		return -1;
-	}
-
-	if (packet->head.qr != DNS_OP_IQUERY) {
-		tlog(TLOG_ERROR, "message type error.\n");
-		return -1;
-	}
-
-	tlog(TLOG_DEBUG, "qdcount = %d, ancount = %d, nscount = %d, nrcount = %d, len = %d, id = %d, rd = %d, ra = %d, rcode = %d\n", packet->head.qdcount,
-		 packet->head.ancount, packet->head.nscount, packet->head.nrcount, inpacket_len, packet->head.id, packet->head.rd, packet->head.ra, packet->head.rcode);
+    int key = 0;
+    struct dns_query_replied *replied_map = NULL;
+
+    if (addr_len > sizeof(struct sockaddr_in6)) {
+		tlog(TLOG_ERROR, "addr length is invalid.");
+        return -1;
+    }
+
+    key = jhash(addr, addr_len, 0);
+    hash_for_each_possible(dns_query->replied_map, replied_map, node, key)
+    {
+        if (memcmp(&replied_map->addr, addr, addr_len) == 0) {
+            return -1;
+        }
+    }
+
+    replied_map = malloc(sizeof(*replied_map));
+    if (replied_map == NULL) {
+        tlog(TLOG_ERROR, "malloc failed");
+        return -1;
+    }
+
+    memcpy(&replied_map->addr, addr, addr_len);
+    hash_add(dns_query->replied_map, &replied_map->node, key);
+    return 0;
+}
 
-	rrs = dns_get_rrs_start(packet, DNS_RRS_QD, &rr_count);
-	for (i = 0; i < rr_count && rrs; i++, rrs = dns_get_rrs_next(packet, rrs)) {
-		dns_get_domain(rrs, domain, DNS_MAX_CNAME_LEN, &qtype, &qclass);
-		tlog(TLOG_DEBUG, "domain: %s qtype: %d  qclass: %d\n", domain, qtype, qclass);
-	}
 
-	query = _dns_client_get_request(packet->head.id, domain);
-	if (query == NULL) {
+static int _dns_client_recv(unsigned char *inpacket, int inpacket_len, struct sockaddr_storage *from, socklen_t from_len)
+{
+    int len;
+    int i;
+    int qtype;
+    int qclass;
+    char domain[DNS_MAX_CNAME_LEN];
+    int rr_count;
+    struct dns_rrs *rrs = NULL;
+    unsigned char packet_buff[DNS_PACKSIZE];
+    struct dns_packet *packet = (struct dns_packet *)packet_buff;
+    int ret = 0;
+    struct dns_query_struct *query;
+    int request_num = 0;
+
+    packet->head.tc = 0;
+    len = dns_decode(packet, DNS_PACKSIZE, inpacket, inpacket_len);
+    if (len != 0) {
+        tlog(TLOG_ERROR, "decode failed, packet len = %d, tc=%d, %d\n", inpacket_len, packet->head.tc, packet->head.id);
+        return -1;
+    }
+
+    if (packet->head.qr != DNS_OP_IQUERY) {
+        tlog(TLOG_ERROR, "message type error.\n");
+        return -1;
+    }
+
+    tlog(TLOG_DEBUG, "qdcount = %d, ancount = %d, nscount = %d, nrcount = %d, len = %d, id = %d, tc = %d, rd = %d, ra = %d, rcode = %d\n", packet->head.qdcount,
+        packet->head.ancount, packet->head.nscount, packet->head.nrcount, inpacket_len, packet->head.id, packet->head.tc, packet->head.rd, packet->head.ra, packet->head.rcode);
+
+    rrs = dns_get_rrs_start(packet, DNS_RRS_QD, &rr_count);
+    for (i = 0; i < rr_count && rrs; i++, rrs = dns_get_rrs_next(packet, rrs)) {
+        dns_get_domain(rrs, domain, DNS_MAX_CNAME_LEN, &qtype, &qclass);
+        tlog(TLOG_DEBUG, "domain: %s qtype: %d  qclass: %d\n", domain, qtype, qclass);
+    }
+
+    query = _dns_client_get_request(packet->head.id, domain);
+    if (query == NULL) {
+        return 0;
+    }
+
+	if (_dns_replied_check_add(query, (struct sockaddr *)from, from_len) != 0) {
 		return 0;
 	}
 
-	request_num = atomic_dec_return(&query->dns_request_sent);
-	if (request_num < 0) {
-		tlog(TLOG_ERROR, "send count is invalid, %d", request_num);
-		return -1;
-	}
+    request_num = atomic_dec_return(&query->dns_request_sent);
+    if (request_num < 0) {
+        tlog(TLOG_ERROR, "send count is invalid, %d", request_num);
+        return -1;
+    }
 
-	if (query->callback) {
-		ret = query->callback(query->domain, DNS_QUERY_RESULT, packet, inpacket, inpacket_len, query->user_ptr);
-	}
+    if (query->callback) {
+        ret = query->callback(query->domain, DNS_QUERY_RESULT, packet, inpacket, inpacket_len, query->user_ptr);
+    }
 
-	if (request_num == 0 || ret) {
-		_dns_client_query_remove(query, 0);
-	}
+    if (request_num == 0 || ret) {
+        _dns_client_query_remove(query, 0);
+    }
 
-	return ret;
+    return ret;
 }
 
 static int _dns_client_process(struct dns_query_struct *dns_query, unsigned long now)
 {
-	int len;
-	unsigned char inpacket[DNS_IN_PACKSIZE];
-	struct sockaddr_storage from;
-	socklen_t from_len = sizeof(from);
-	char from_host[DNS_MAX_CNAME_LEN];
-
-	len = recvfrom(client.udp, inpacket, sizeof(inpacket), 0, (struct sockaddr *)&from, (socklen_t *)&from_len);
-	if (len < 0) {
-		tlog(TLOG_ERROR, "recvfrom failed, %s\n", strerror(errno));
-		return -1;
-	}
-
-	tlog(TLOG_DEBUG, "recv from %s", gethost_by_addr(from_host, (struct sockaddr *)&from, from_len));
-
-	if (_dns_client_recv(inpacket, len, &from, from_len) != 0) {
-		int fd = open("dns.bin", O_CREAT | O_TRUNC | O_RDWR);
-		write(fd, inpacket, len);
-		close(fd);
-		return -1;
-	}
-
-	return 0;
+    int len;
+    unsigned char inpacket[DNS_IN_PACKSIZE];
+    struct sockaddr_storage from;
+    socklen_t from_len = sizeof(from);
+    char from_host[DNS_MAX_CNAME_LEN];
+
+    len = recvfrom(client.udp, inpacket, sizeof(inpacket), 0, (struct sockaddr *)&from, (socklen_t *)&from_len);
+    if (len < 0) {
+        tlog(TLOG_ERROR, "recvfrom failed, %s\n", strerror(errno));
+        return -1;
+    }
+
+    tlog(TLOG_DEBUG, "recv from %s", gethost_by_addr(from_host, (struct sockaddr *)&from, from_len));
+
+    if (_dns_client_recv(inpacket, len, &from, from_len) != 0) {
+        int fd = open("dns.bin", O_CREAT | O_TRUNC | O_RDWR);
+        write(fd, inpacket, len);
+        close(fd);
+        return -1;
+    }
+
+    return 0;
 }
 
 static void *_dns_client_work(void *arg)
 {
-	struct epoll_event events[DNS_MAX_EVENTS + 1];
-	int num;
-	int i;
-	unsigned long now = {0};
-	unsigned int sleep = 100;
-	int sleep_time;
-	unsigned int expect_time = 0;
-
-	now = get_tick_count() - sleep;
-	expect_time = now + sleep;
-	while (client.run) {
-		now = get_tick_count();
-		if (now >= expect_time) {
-			_dns_client_period_run();
-			sleep_time = sleep - (now - expect_time);
-			if (sleep_time < 0) {
-				sleep_time = 0;
-				expect_time = now;
-			}
-			expect_time += sleep;
-		}
-
-		num = epoll_wait(client.epoll_fd, events, DNS_MAX_EVENTS, sleep_time);
-		if (num < 0) {
-			usleep(100000);
-			continue;
-		}
-
-		for (i = 0; i < num; i++) {
-			struct epoll_event *event = &events[i];
-			struct dns_query_struct *dns_query = (struct dns_query_struct *)event->data.ptr;
-			_dns_client_process(dns_query, now);
-		}
-	}
-
-	close(client.epoll_fd);
-	client.epoll_fd = -1;
-
-	return NULL;
+    struct epoll_event events[DNS_MAX_EVENTS + 1];
+    int num;
+    int i;
+    unsigned long now = { 0 };
+    unsigned int sleep = 100;
+    int sleep_time;
+    unsigned int expect_time = 0;
+
+    now = get_tick_count() - sleep;
+    expect_time = now + sleep;
+    while (client.run) {
+        now = get_tick_count();
+        if (now >= expect_time) {
+            _dns_client_period_run();
+            sleep_time = sleep - (now - expect_time);
+            if (sleep_time < 0) {
+                sleep_time = 0;
+                expect_time = now;
+            }
+            expect_time += sleep;
+        }
+
+        num = epoll_wait(client.epoll_fd, events, DNS_MAX_EVENTS, sleep_time);
+        if (num < 0) {
+            usleep(100000);
+            continue;
+        }
+
+        for (i = 0; i < num; i++) {
+            struct epoll_event *event = &events[i];
+            struct dns_query_struct *dns_query = (struct dns_query_struct *)event->data.ptr;
+            _dns_client_process(dns_query, now);
+        }
+    }
+
+    close(client.epoll_fd);
+    client.epoll_fd = -1;
+
+    return NULL;
 }
 
 static int _dns_client_send_udp(struct dns_server_info *server_info, void *packet, int len)
 {
-	int send_len = 0;
-	send_len = sendto(client.udp, packet, len, 0, (struct sockaddr *)&server_info->addr, server_info->addr_len);
-	if (send_len != len) {
-		return -1;
-	}
+    int send_len = 0;
+    send_len = sendto(client.udp, packet, len, 0, (struct sockaddr *)&server_info->addr, server_info->addr_len);
+    if (send_len != len) {
+        return -1;
+    }
 
-	return 0;
+    return 0;
 }
 
 static int _dns_client_send_packet(struct dns_query_struct *query, void *packet, int len)
 {
-	struct dns_server_info *server_info, *tmp;
-	int ret = 0;
-
-	query->send_tick = get_tick_count();
-	pthread_mutex_lock(&client.server_list_lock);
-	list_for_each_entry_safe(server_info, tmp, &client.dns_server_list, list)
-	{
-		atomic_inc(&query->dns_request_sent);
-		switch (server_info->type) {
-		case DNS_SERVER_UDP:
-			ret = _dns_client_send_udp(server_info, packet, len);
-			break;
-		default:
-			ret = -1;
-			break;
-		}
-
-		if (ret != 0) {
-			char server_addr[128];
-			tlog(TLOG_ERROR, "send query to %s failed, %s", gethost_by_addr(server_addr, &server_info->addr, server_info->addr_len), strerror(errno));
-			atomic_dec(&query->dns_request_sent);
-			continue;
-		}
-	}
-	pthread_mutex_unlock(&client.server_list_lock);
-	return 0;
+    struct dns_server_info *server_info, *tmp;
+    int ret = 0;
+	
+    query->send_tick = get_tick_count();
+    pthread_mutex_lock(&client.server_list_lock);
+    list_for_each_entry_safe(server_info, tmp, &client.dns_server_list, list)
+    {
+        atomic_inc(&query->dns_request_sent);
+        switch (server_info->type) {
+        case DNS_SERVER_UDP:
+            ret = _dns_client_send_udp(server_info, packet, len);
+            break;
+        default:
+            ret = -1;
+            break;
+        }
+
+        if (ret != 0) {
+            char server_addr[128];
+            tlog(TLOG_ERROR, "send query to %s failed, %s", gethost_by_addr(server_addr, &server_info->addr, server_info->addr_len), strerror(errno));
+            atomic_dec(&query->dns_request_sent);
+            continue;
+        }
+    }
+    pthread_mutex_unlock(&client.server_list_lock);
+    return 0;
 }
 
 static int _dns_client_send_query(struct dns_query_struct *query, char *doamin)
 {
-	unsigned char packet_buff[DNS_PACKSIZE];
-	unsigned char inpacket[DNS_IN_PACKSIZE];
-	struct dns_packet *packet = (struct dns_packet *)packet_buff;
-	int encode_len;
-
-	struct dns_head head;
-	memset(&head, 0, sizeof(head));
-	head.id = query->sid;
-	head.qr = DNS_QR_QUERY;
-	head.opcode = DNS_OP_QUERY;
-	head.aa = 1;
-	head.rd = 1;
-	head.ra = 1;
-	head.rcode = 0;
-
-	dns_packet_init(packet, DNS_PACKSIZE, &head);
-	dns_add_domain(packet, doamin, query->qtype, DNS_C_IN);
-	encode_len = dns_encode(inpacket, DNS_IN_PACKSIZE, packet);
-	if (encode_len <= 0) {
-		tlog(TLOG_ERROR, "encode query failed.");
-		return -1;
-	}
-
-	return _dns_client_send_packet(query, inpacket, encode_len);
+    unsigned char packet_buff[DNS_PACKSIZE];
+    unsigned char inpacket[DNS_IN_PACKSIZE];
+    struct dns_packet *packet = (struct dns_packet *)packet_buff;
+    int encode_len;
+
+    struct dns_head head;
+    memset(&head, 0, sizeof(head));
+    head.id = query->sid;
+    head.qr = DNS_QR_QUERY;
+    head.opcode = DNS_OP_QUERY;
+    head.aa = 0;
+    head.rd = 1;
+    head.ra = 0;
+    head.rcode = 0;
+
+    dns_packet_init(packet, DNS_PACKSIZE, &head);
+    dns_add_domain(packet, doamin, query->qtype, DNS_C_IN);
+    encode_len = dns_encode(inpacket, DNS_IN_PACKSIZE, packet);
+    if (encode_len <= 0) {
+        tlog(TLOG_ERROR, "encode query failed.");
+        return -1;
+    }
+
+    return _dns_client_send_packet(query, inpacket, encode_len);
 }
 
 int dns_client_query(char *domain, int qtype, dns_client_callback callback, void *user_ptr)
 {
-	struct dns_query_struct *query = NULL;
-	int ret = 0;
-	unsigned int key = 0;
-
-	query = malloc(sizeof(*query));
-	if (query == NULL) {
-		goto errout;
-	}
-	memset(query, 0, sizeof(*query));
-	INIT_HLIST_NODE(&query->domain_node);
-	INIT_LIST_HEAD(&query->dns_request_list);
-	atomic_set(&query->refcnt, 0);
-	atomic_set(&query->dns_request_sent, 0);
-	strncpy(query->domain, domain, DNS_MAX_CNAME_LEN);
-	query->user_ptr = user_ptr;
-	query->callback = callback;
-	query->qtype = qtype;
-	query->send_tick = 0;
-	query->sid = atomic_inc_return(&dns_client_sid);
-
-	_dns_client_query_get(query);
-	key = hash_string(domain);
-	key = jhash(&query->sid, sizeof(query->sid), key);
-	pthread_mutex_lock(&client.domain_map_lock);
-	list_add_tail(&query->dns_request_list, &client.dns_request_list);
-	hash_add(client.domain_map, &query->domain_node, key);
-	pthread_mutex_unlock(&client.domain_map_lock);
-
-	ret = _dns_client_send_query(query, domain);
-	if (ret != 0) {
-		goto errout_del_list;
-	}
-
-	tlog(TLOG_INFO, "send request %s, id %d\n", domain, query->sid);
-
-	return 0;
+    struct dns_query_struct *query = NULL;
+    int ret = 0;
+    unsigned int key = 0;
+
+    query = malloc(sizeof(*query));
+    if (query == NULL) {
+        goto errout;
+    }
+    memset(query, 0, sizeof(*query));
+    INIT_HLIST_NODE(&query->domain_node);
+    INIT_LIST_HEAD(&query->dns_request_list);
+    atomic_set(&query->refcnt, 0);
+    atomic_set(&query->dns_request_sent, 0);
+    hash_init(query->replied_map);
+    strncpy(query->domain, domain, DNS_MAX_CNAME_LEN);
+    query->user_ptr = user_ptr;
+    query->callback = callback;
+    query->qtype = qtype;
+    query->send_tick = 0;
+    query->sid = atomic_inc_return(&dns_client_sid);
+
+    _dns_client_query_get(query);
+    key = hash_string(domain);
+    key = jhash(&query->sid, sizeof(query->sid), key);
+    pthread_mutex_lock(&client.domain_map_lock);
+    list_add_tail(&query->dns_request_list, &client.dns_request_list);
+    hash_add(client.domain_map, &query->domain_node, key);
+    pthread_mutex_unlock(&client.domain_map_lock);
+
+    ret = _dns_client_send_query(query, domain);
+    if (ret != 0) {
+        goto errout_del_list;
+    }
+
+    tlog(TLOG_INFO, "send request %s, id %d\n", domain, query->sid);
+
+    return 0;
 errout_del_list:
-	atomic_dec(&query->refcnt);
-	pthread_mutex_lock(&client.domain_map_lock);
-	list_del_init(&query->dns_request_list);
-	hash_del(&query->domain_node);
-	pthread_mutex_unlock(&client.domain_map_lock);
+    atomic_dec(&query->refcnt);
+    pthread_mutex_lock(&client.domain_map_lock);
+    list_del_init(&query->dns_request_list);
+    hash_del(&query->domain_node);
+    pthread_mutex_unlock(&client.domain_map_lock);
 errout:
-	if (query) {
-		tlog(TLOG_ERROR, "release %p", query);
-		free(query);
-	}
-	return -1;
+    if (query) {
+        tlog(TLOG_ERROR, "release %p", query);
+        free(query);
+    }
+    return -1;
 }
 
 int dns_client_query_raw(char *domain, int qtype, unsigned char *raw, int raw_len, void *user_ptr)
 {
-	return -1;
+    return -1;
 }
 
 static struct addrinfo *_dns_server_getaddr(const char *host, const char *port, int type, int protocol)
 {
-	struct addrinfo hints;
-	struct addrinfo *result = NULL;
-
-	memset(&hints, 0, sizeof(hints));
-	hints.ai_family = AF_UNSPEC;
-	hints.ai_socktype = type;
-	hints.ai_protocol = protocol;
-	hints.ai_flags = AI_PASSIVE;
-	if (getaddrinfo(host, port, &hints, &result) != 0) {
-		tlog(TLOG_ERROR, "get addr info failed. %s\n", strerror(errno));
-		goto errout;
-	}
-
-	return result;
+    struct addrinfo hints;
+    struct addrinfo *result = NULL;
+
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_family = AF_UNSPEC;
+    hints.ai_socktype = type;
+    hints.ai_protocol = protocol;
+    hints.ai_flags = AI_PASSIVE;
+    if (getaddrinfo(host, port, &hints, &result) != 0) {
+        tlog(TLOG_ERROR, "get addr info failed. %s\n", strerror(errno));
+        goto errout;
+    }
+
+    return result;
 errout:
-	if (result) {
-		freeaddrinfo(result);
-	}
-	return NULL;
+    if (result) {
+        freeaddrinfo(result);
+    }
+    return NULL;
 }
 
 int dns_client_start(void)
 {
-	struct epoll_event event;
-	event.events = EPOLLIN;
-	event.data.fd = client.udp;
-	if (epoll_ctl(client.epoll_fd, EPOLL_CTL_ADD, client.udp, &event) != 0) {
-		tlog(TLOG_ERROR, "epoll ctl failed.");
-		return -1;
-	}
-
-	return 0;
+    struct epoll_event event;
+    event.events = EPOLLIN;
+    event.data.fd = client.udp;
+    if (epoll_ctl(client.epoll_fd, EPOLL_CTL_ADD, client.udp, &event) != 0) {
+        tlog(TLOG_ERROR, "epoll ctl failed.");
+        return -1;
+    }
+
+    return 0;
 }
 
 int dns_client_socket(void)
 {
-	int fd = -1;
-	struct addrinfo *gai = NULL;
+    int fd = -1;
+    struct addrinfo *gai = NULL;
 
-	gai = _dns_server_getaddr(NULL, "53", SOCK_DGRAM, 0);
-	if (gai == NULL) {
-		tlog(TLOG_ERROR, "get address failed.\n");
-		goto errout;
-	}
+    gai = _dns_server_getaddr(NULL, "53", SOCK_DGRAM, 0);
+    if (gai == NULL) {
+        tlog(TLOG_ERROR, "get address failed.\n");
+        goto errout;
+    }
 
-	fd = socket(gai->ai_family, gai->ai_socktype, gai->ai_protocol);
-	if (fd < 0) {
-		tlog(TLOG_ERROR, "create socket failed.\n");
-		goto errout;
-	}
+    fd = socket(gai->ai_family, gai->ai_socktype, gai->ai_protocol);
+    if (fd < 0) {
+        tlog(TLOG_ERROR, "create socket failed.\n");
+        goto errout;
+    }
 
-	client.udp = fd;
-	freeaddrinfo(gai);
+    client.udp = fd;
+    freeaddrinfo(gai);
 
-	return fd;
+    return fd;
 errout:
-	if (fd > 0) {
-		close(fd);
-	}
-
-	if (gai) {
-		freeaddrinfo(gai);
-	}
-	return -1;
+    if (fd > 0) {
+        close(fd);
+    }
+
+    if (gai) {
+        freeaddrinfo(gai);
+    }
+    return -1;
 }
 
 void dns_debug(void)
 {
-	unsigned char data[1024];
-	int len;
-	char buff[4096];
-
-	int fd = open("dns.bin", O_RDWR);
-	if (fd < 0) {
-		return;
-	}
-	len = read(fd, data, 1024);
-	close(fd);
-	if (len < 0) {
-		return;
-	}
-
-	struct dns_packet *packet = (struct dns_packet *)buff;
-	if (dns_decode(packet, 4096, data, len) != 0) {
-		tlog(TLOG_ERROR, "decode failed.\n");
-	}
-
-	memset(data, 0, sizeof(data));
-	len = dns_encode(data, 1024, packet);
-	if (len < 0) {
-		tlog(TLOG_ERROR, "encode failed.\n");
-	}
-
-	fd = open("dns-cmp.bin", O_CREAT | O_TRUNC | O_RDWR);
-	write(fd, data, len);
-	close(fd);
+    unsigned char data[1024];
+    int len;
+    char buff[4096];
+
+    int fd = open("dns.bin", O_RDWR);
+    if (fd < 0) {
+        return;
+    }
+    len = read(fd, data, 1024);
+    close(fd);
+    if (len < 0) {
+        return;
+    }
+
+    struct dns_packet *packet = (struct dns_packet *)buff;
+    if (dns_decode(packet, 4096, data, len) != 0) {
+        tlog(TLOG_ERROR, "decode failed.\n");
+    }
+
+    memset(data, 0, sizeof(data));
+    len = dns_encode(data, 1024, packet);
+    if (len < 0) {
+        tlog(TLOG_ERROR, "encode failed.\n");
+    }
+
+    fd = open("dns-cmp.bin", O_CREAT | O_TRUNC | O_RDWR);
+    write(fd, data, len);
+    close(fd);
 }
 
 int dns_client_init()
 {
-	pthread_attr_t attr;
-	int epollfd = -1;
-	int ret;
-	int fd = -1;
-
-	if (client.epoll_fd > 0) {
-		return -1;
-	}
-
-	memset(&client, 0, sizeof(client));
-	pthread_attr_init(&attr);
-
-	epollfd = epoll_create1(EPOLL_CLOEXEC);
-	if (epollfd < 0) {
-		tlog(TLOG_ERROR, "create epoll failed, %s\n", strerror(errno));
-		goto errout;
-	}
-
-	fd = dns_client_socket();
-	if (fd < 0) {
-		tlog(TLOG_ERROR, "create client socket failed.\n");
-		goto errout;
-	}
-
-	pthread_mutex_init(&client.server_list_lock, 0);
-	INIT_LIST_HEAD(&client.dns_server_list);
-
-	pthread_mutex_init(&client.domain_map_lock, 0);
-	hash_init(client.domain_map);
-	INIT_LIST_HEAD(&client.dns_request_wait_list);
-	INIT_LIST_HEAD(&client.dns_request_list);
-
-	client.epoll_fd = epollfd;
-	client.run = 1;
-	client.udp = fd;
-	ret = pthread_create(&client.tid, &attr, _dns_client_work, NULL);
-	if (ret != 0) {
-		tlog(TLOG_ERROR, "create client work thread failed, %s\n", strerror(errno));
-		goto errout;
-	}
-
-	if (dns_client_start()) {
-		tlog(TLOG_ERROR, "start client failed.\n");
-		goto errout;
-	}
-
-	return 0;
+    pthread_attr_t attr;
+    int epollfd = -1;
+    int ret;
+    int fd = -1;
+
+    if (client.epoll_fd > 0) {
+        return -1;
+    }
+
+    memset(&client, 0, sizeof(client));
+    pthread_attr_init(&attr);
+
+    epollfd = epoll_create1(EPOLL_CLOEXEC);
+    if (epollfd < 0) {
+        tlog(TLOG_ERROR, "create epoll failed, %s\n", strerror(errno));
+        goto errout;
+    }
+
+    fd = dns_client_socket();
+    if (fd < 0) {
+        tlog(TLOG_ERROR, "create client socket failed.\n");
+        goto errout;
+    }
+
+    pthread_mutex_init(&client.server_list_lock, 0);
+    INIT_LIST_HEAD(&client.dns_server_list);
+
+    pthread_mutex_init(&client.domain_map_lock, 0);
+    hash_init(client.domain_map);
+    INIT_LIST_HEAD(&client.dns_request_wait_list);
+    INIT_LIST_HEAD(&client.dns_request_list);
+
+    client.epoll_fd = epollfd;
+    client.run = 1;
+    client.udp = fd;
+    ret = pthread_create(&client.tid, &attr, _dns_client_work, NULL);
+    if (ret != 0) {
+        tlog(TLOG_ERROR, "create client work thread failed, %s\n", strerror(errno));
+        goto errout;
+    }
+
+    if (dns_client_start()) {
+        tlog(TLOG_ERROR, "start client failed.\n");
+        goto errout;
+    }
+
+    return 0;
 errout:
-	if (client.tid > 0) {
-		void *retval = NULL;
-		client.run = 0;
-		pthread_join(client.tid, &retval);
-	}
+    if (client.tid > 0) {
+        void *retval = NULL;
+        client.run = 0;
+        pthread_join(client.tid, &retval);
+    }
 
-	if (client.udp > 0) {
-		close(client.udp);
-		client.udp = -1;
-	}
+    if (client.udp > 0) {
+        close(client.udp);
+        client.udp = -1;
+    }
 
-	if (epollfd) {
-		close(epollfd);
-	}
+    if (epollfd) {
+        close(epollfd);
+    }
 
-	pthread_mutex_destroy(&client.server_list_lock);
-	pthread_mutex_destroy(&client.domain_map_lock);
+    pthread_mutex_destroy(&client.server_list_lock);
+    pthread_mutex_destroy(&client.domain_map_lock);
 
-	return -1;
+    return -1;
 }
 
 void dns_client_exit()
 {
-	if (client.tid > 0) {
-		void *ret = NULL;
-		client.run = 0;
-		pthread_join(client.tid, &ret);
-	}
-
-	if (client.udp > 0) {
-		close(client.udp);
-	}
-
-	pthread_mutex_destroy(&client.server_list_lock);
-	pthread_mutex_destroy(&client.domain_map_lock);
+    if (client.tid > 0) {
+        void *ret = NULL;
+        client.run = 0;
+        pthread_join(client.tid, &ret);
+    }
+
+    if (client.udp > 0) {
+        close(client.udp);
+    }
+
+    pthread_mutex_destroy(&client.server_list_lock);
+    pthread_mutex_destroy(&client.domain_map_lock);
 }

dns_server.c

@@ -211,7 +211,7 @@ static int _dns_reply(struct dns_request *request)
 	head.id = request->id;
 	head.qr = DNS_QR_ANSWER;
 	head.opcode = DNS_OP_QUERY;
-	head.rd = 0;
+	head.rd = 1;
 	head.ra = 0;
 	head.aa = 0;
 	head.tc = 0;
@@ -411,13 +411,14 @@ static int _dns_server_process_answer(struct dns_request *request, char *domain,
 	struct dns_rrs *rrs = NULL;
 
 	if (packet->head.rcode != DNS_RC_NOERROR) {
-		if (request->rcode == (unsigned short)-1) {
+		if (request->rcode == DNS_RC_SERVFAIL) {
 			request->rcode = packet->head.rcode;
 		}
 		tlog(TLOG_ERROR, "inquery failed, %s, rcode = %d, id = %d\n", domain, packet->head.rcode, packet->head.id);
 		return -1;
 	}
 
+
 	request->rcode = packet->head.rcode;
 
 	for (j = 1; j < DNS_RRS_END; j++) {

smartdns.c

@@ -116,7 +116,7 @@ int smartdns_init()
 	}
 
 	tlog_setlogscreen(1);
-	tlog_setlevel(TLOG_DEBUG);
+	tlog_setlevel(TLOG_INFO);
 
 	if (dns_conf_server_num <= 0) {
 		if (smartdns_load_from_resolv() != 0) {

smartdns.conf

@@ -5,12 +5,13 @@ port 53
 cache-size 1024
 loglevel info
 
+#server 192.168.1.1
 server 114.114.114.114
 server 123.207.137.88
 server 119.29.29.29
 server 223.5.5.5
 server 208.67.222.222:5353
 server 202.141.178.13:5353
-#server 77.88.8.8:53
+server 77.88.8.8:53
 server 202.141.162.123:53
 server 101.132.183.99:53