serve-expired: support config reply ttl

compile: remove O_CLOEXEC flags
cache: support persist cache when restart smartdns
2020-09-06 15:21:37 +08:00 · 2020-09-05 19:37:50 +08:00 · 2020-09-05 12:55:30 +08:00 · 2020-09-02 22:03:24 +08:00 · 2020-08-27 23:34:22 +08:00 · 2020-08-25 22:02:45 +08:00
18 changed files with 1284 additions and 266 deletions
--- a/ReadMe.md
+++ b/ReadMe.md
@@ -504,6 +504,8 @@ https://github.com/pymumu/smartdns/releases
 |bind|DNS监听端口号|[::]:53|可绑定多个端口<br>`IP:PORT`: 服务器IP，端口号。<br>`[-group]`: 请求时使用的DNS服务器组。<br>`[-no-rule-addr]`：跳过address规则。<br>`[-no-rule-nameserver]`：跳过Nameserver规则。<br>`[-no-rule-ipset]`：跳过Ipset规则。<br>`[no-rule-soa]`：跳过SOA(#)规则.<br>`[no-dualstack-selection]`：停用双栈测速。<br>`[-no-speed-check]`：停用测速。<br>`[-no-cache]`：停止缓存|bind :53
 |bind-tcp|TCP DNS监听端口号|[::]:53|可绑定多个端口<br>`IP:PORT`: 服务器IP，端口号。<br>`[-group]`: 请求时使用的DNS服务器组。<br>`[-no-rule-addr]`：跳过address规则。<br>`[-no-rule-nameserver]`：跳过Nameserver规则。<br>`[-no-rule-ipset]`：跳过Ipset规则。<br>`[no-rule-soa]`：跳过SOA(#)规则.<br>`[no-dualstack-selection]`：停用双栈测速。<br>`[-no-speed-check]`：停用测速。<br>`[-no-cache]`：停止缓存|bind-tcp :53
 |cache-size|域名结果缓存个数|512|数字|cache-size 512
+|cache-persist|是否持久化缓存|no|[yes\|no]|cache-persist yes
+|cache-file|缓存持久化文件路径|/tmp/smartdns.cache|路径|cache-file /tmp/smartdns.cache
 |tcp-idle-time|TCP链接空闲超时时间|120|数字|tcp-idle-time 120
 |rr-ttl|域名结果TTL|远程查询结果|大于0的数字|rr-ttl 600
 |rr-ttl-min|允许的最小TTL值|远程查询结果|大于0的数字|rr-ttl-min 60
@@ -535,6 +537,7 @@ https://github.com/pymumu/smartdns/releases
 |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
+|serve-expired-reply-ttl|回应的过期缓存TTL|5|秒，0：表示停用超时，> 0表示指定的超时的秒数|serve-expired-reply-ttl 30
 |dualstack-ip-selection|双栈IP优选|no|[yes\|no]|dualstack-ip-selection yes
 |dualstack-ip-selection-threshold|双栈IP优选阈值|30ms|毫秒|dualstack-ip-selection-threshold [0-1000]
 |ca-file|证书文件|/etc/ssl/certs/ca-certificates.crt|路径|ca-file /etc/ssl/certs/ca-certificates.crt
--- a/ReadMe_en.md
+++ b/ReadMe_en.md
@@ -498,6 +498,8 @@ Note: Merlin firmware is derived from ASUS firmware and can theoretically be use
 |bind|DNS listening port number|[::]:53|Support binding multiple ports<br>`IP:PORT`: server IP, port number. <br>`[-group]`: The DNS server group used when requesting. <br>`[-no-rule-addr]`: Skip the address rule. <br>`[-no-rule-nameserver]`: Skip the Nameserver rule. <br>`[-no-rule-ipset]`: Skip the Ipset rule. <br>`[-no-rule-soa]`: Skip address SOA(#) rules.<br>`[-no-dualstack-selection]`: Disable dualstack ip selection.<br>`[-no-speed-check]`: Disable speed measurement. <br>`[-no-cache]`: stop caching |bind :53
 |bind-tcp|TCP mode DNS listening port number|[::]:53|Support binding multiple ports<br>`IP:PORT`: server IP, port number. <br>`[-group]`: The DNS server group used when requesting. <br>`[-no-rule-addr]`: Skip the address rule. <br>`[-no-rule-nameserver]`: Skip the Nameserver rule. <br>`[-no-rule-ipset]`: Skip the Ipset rule. <br>`[-no-rule-soa]`: Skip address SOA(#) rules.<br>`[-no-dualstack-selection]`: Disable dualstack ip selection.<br>`[-no-speed-check]`: Disable speed measurement. <br>`[-no-cache]`: stop caching |bind-tcp :53
 |cache-size|Domain name result cache number|512|integer|cache-size 512
+|cache-persist|enable persist cache|no|[yes\|no]|cache-persist yes
+|cache-file|cache persist file|/tmp/smartdns.cache|路径|cache-file /tmp/smartdns.cache
 |tcp-idle-time|TCP connection idle timeout|120|integer|tcp-idle-time 120
 |rr-ttl|Domain name TTL|Remote query result|number greater than 0|rr-ttl 600
 |rr-ttl-min|Domain name Minimum TTL|Remote query result|number greater than 0|rr-ttl-min 60
@@ -529,6 +531,7 @@ Note: Merlin firmware is derived from ASUS firmware and can theoretically be use
 |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
+|serve-expired-reply-ttl|TTL value to use when replying with expired data|5|second，0：disable，> 0  seconds after expiration|serve-expired-reply-ttl 30
 |dualstack-ip-selection|Dualstack ip selection|no|[yes\|no]|dualstack-ip-selection yes
 |dualstack-ip-selection-threshold|Dualstack ip select threadhold|30ms|millisecond|dualstack-ip-selection-threshold [0-1000]
 |ca-file|certificate file|/etc/ssl/certs/ca-certificates.crt|path|ca-file /etc/ssl/certs/ca-certificates.crt
--- a/etc/smartdns/smartdns.conf
+++ b/etc/smartdns/smartdns.conf
@@ -38,7 +38,13 @@ bind [::]:53
 # dns cache size
 # cache-size [number]
 #   0: for no cache
-cache-size 512
+cache-size 4096
+
+# enable persist cache when restart
+# cache-persist yes
+
+# cache persist file
+# cache-file /tmp/smartdns.cache

 # prefetch domain
 # prefetch-domain [yes|no]
@@ -52,6 +58,10 @@ cache-size 512
 # serve-expired-ttl [num]
 # serve-expired-ttl 0

+# reply TTL value to use when replying with expired data
+# serve-expired-reply-ttl [num]
+# serve-expired-reply-ttl 30
+
 # List of hosts that supply bogus NX domain results 
 # bogus-nxdomain [ip/subnet]

--- a/package/optware/S50smartdns
+++ b/package/optware/S50smartdns
@@ -332,9 +332,28 @@ case "$1" in
 		return 0
 	fi

-	if [ ! -d "/proc/$pid" ]; then
-		return 0;
+	kill -15 "$pid" 2>/dev/null
+	SLEEP=`which usleep`
+	SLEEPTIME=200000
+	if [ -z "$SLEEP" ]; then
+		SLEEP="sleep"
+		SLEEPTIME=0.2
 	fi
+	N=30
+	while [ $N -gt 0 ]
+	do
+		pid="$(cat "$SMARTDNS_PID" | head -n 1 2>/dev/null)"
+		if [ -z "$pid" ]; then
+			return 0
+		fi
+
+		if [ ! -d "/proc/$pid" ]; then
+			return 0;
+		fi
+
+		$SLEEP $SLEEPTIME 2>/dev/null
+		N=$((N-1))
+	done

 	kill -9 "$pid" 2>/dev/null
 	;;
--- a/package/redhat/smartdns.spec
+++ b/package/redhat/smartdns.spec
@@ -0,0 +1,63 @@
+Name:           smartdns
+Version:        31
+Release:        1%{?dist}
+Summary:        smartdns
+
+License:        GPL 3.0
+URL:            https://github.com/pymumu/smartdns
+Source0:        smartdns-Release31.tar.gz
+
+BuildRequires:  glibc
+Requires:       glibc
+Requires:       systemd
+
+%description
+A local DNS server to obtain the fastest website IP for the best Internet experience.
+
+%prep
+%setup -q -n smartdns-Release31
+
+%build
+cd src
+make %{?_smp_mflags}
+
+%install
+rm -rf $RPM_BUILD_ROOT
+
+%{__install} -D -m 755 src/smartdns $RPM_BUILD_ROOT%{_sbindir}/smartdns
+%{__install} -D -m 644 etc/smartdns/smartdns.conf $RPM_BUILD_ROOT%{_sysconfdir}/smartdns/smartdns.conf
+%{__install} -D -m 644 systemd/smartdns.service.in $RPM_BUILD_ROOT%{_unitdir}/smartdns.service
+
+
+cat > $RPM_BUILD_ROOT%{_unitdir}/smartdns.service <<EOF
+[Unit]
+Description=smartdns
+ConditionFileIsExecutable=/usr/sbin/smartdns
+After=syslog.target network-online.target
+
+[Service]
+Type=simple
+ExecStart=/usr/sbin/smartdns -c /etc/smartdns/smartdns.conf -f
+PIDFile=/run/smartdns.pid
+Restart=on-failure
+KillMode=process
+
+[Install]
+WantedBy=multi-user.target
+EOF
+
+
+%files
+%defattr(-,root,root,-)
+%{_sbindir}/smartdns
+%config(noreplace) %{_sysconfdir}/smartdns/smartdns.conf
+%{_unitdir}/smartdns.service
+
+%post
+%systemd_post %{name}.service
+
+%preun
+%systemd_preun %{name}.service
+
+%postun
+%systemd_postun_with_restart %{name}.service
--- a/src/dns_cache.c
+++ b/src/dns_cache.c
@@ -19,7 +19,11 @@
 #include "dns_cache.h"
 #include "stringutil.h"
 #include "tlog.h"
+#include <errno.h>
+#include <fcntl.h>
 #include <pthread.h>
+#include <string.h>
+#include <sys/types.h>

 #define DNS_CACHE_MAX_HITNUM 5000
 #define DNS_CACHE_HITNUM_STEP 2
@@ -65,7 +69,7 @@ static __attribute__((unused)) struct dns_cache *_dns_cache_last(void)
 	return list_last_entry(&dns_cache_head.cache_list, struct dns_cache, list);
 }

-static struct dns_cache *_dns_cache_first(void)
+static struct dns_cache *_dns_inactive_cache_first(void)
 {
 	struct dns_cache *dns_cache = NULL;

@@ -82,6 +86,7 @@ static void _dns_cache_delete(struct dns_cache *dns_cache)
 	hash_del(&dns_cache->node);
 	list_del_init(&dns_cache->list);
 	atomic_dec(&dns_cache_head.num);
+	dns_cache_data_free(dns_cache->cache_data);
 	free(dns_cache);
 }

@@ -118,10 +123,89 @@ static void _dns_cache_move_inactive(struct dns_cache *dns_cache)
 	list_add_tail(&dns_cache->list, &dns_cache_head.inactive_list);
 }

-int dns_cache_replace(char *domain, char *cname, int cname_ttl, int ttl, dns_type_t qtype, unsigned char *addr,
-					  int addr_len, int speed)
+enum CACHE_TYPE dns_cache_data_type(struct dns_cache_data *cache_data)
+{
+	return cache_data->head.cache_type;
+}
+
+uint32_t dns_cache_get_cache_flag(struct dns_cache_data *cache_data)
+{
+	return cache_data->head.cache_flag;
+}
+
+void dns_cache_data_free(struct dns_cache_data *data)
+{
+	if (data == NULL) {
+		return;
+	}
+
+	free(data);
+}
+
+struct dns_cache_data *dns_cache_new_data_addr(uint32_t cache_flag, char *cname, int cname_ttl, unsigned char *addr,
+											   int addr_len)
+{
+	struct dns_cache_addr *cache_addr = malloc(sizeof(struct dns_cache_addr));
+	memset(cache_addr, 0, sizeof(struct dns_cache_addr));
+	if (cache_addr == NULL) {
+		return NULL;
+	}
+
+	if (addr_len == DNS_RR_A_LEN) {
+		memcpy(cache_addr->addr_data.addr, addr, DNS_RR_A_LEN);
+	} else if (addr_len != DNS_RR_AAAA_LEN) {
+		memcpy(cache_addr->addr_data.addr, addr, DNS_RR_AAAA_LEN);
+	} else {
+		goto errout;
+	}
+
+	if (cname) {
+		safe_strncpy(cache_addr->addr_data.cname, cname, DNS_MAX_CNAME_LEN);
+		cache_addr->addr_data.cname_ttl = cname_ttl;
+	}
+
+	cache_addr->head.cache_flag = cache_flag;
+	cache_addr->head.cache_type = CACHE_TYPE_ADDR;
+	cache_addr->head.size = sizeof(struct dns_cache_addr) - sizeof(struct dns_cache_data_head);
+
+	return (struct dns_cache_data *)cache_addr;
+
+errout:
+	if (cache_addr) {
+		free(cache_addr);
+		cache_addr = NULL;
+	}
+
+	return NULL;
+}
+
+struct dns_cache_data *dns_cache_new_data_packet(uint32_t cache_flag, void *packet, size_t packet_len)
+{
+	struct dns_cache_packet *cache_packet = NULL;
+	size_t data_size = 0;
+	if (packet == NULL || packet_len <= 0) {
+		return NULL;
+	}
+
+	data_size = sizeof(*cache_packet) + packet_len;
+	cache_packet = malloc(data_size);
+	if (cache_packet == NULL) {
+		return NULL;
+	}
+
+	memcpy(cache_packet->data, packet, packet_len);
+
+	cache_packet->head.cache_flag = cache_flag;
+	cache_packet->head.cache_type = CACHE_TYPE_PACKET;
+	cache_packet->head.size = packet_len;
+
+	return (struct dns_cache_data *)cache_packet;
+}
+
+int dns_cache_replace(char *domain, int ttl, dns_type_t qtype, int speed, struct dns_cache_data *cache_data)
 {
 	struct dns_cache *dns_cache = NULL;
+	struct dns_cache_data *old_cache_data = NULL;

 	if (dns_cache_head.size <= 0) {
 		return 0;
@@ -130,7 +214,7 @@ int dns_cache_replace(char *domain, char *cname, int cname_ttl, int ttl, dns_typ
 	/* lookup existing cache */
 	dns_cache = dns_cache_lookup(domain, qtype);
 	if (dns_cache == NULL) {
-		return dns_cache_insert(domain, cname, cname_ttl, ttl, qtype, addr, addr_len, speed);
+		return dns_cache_insert(domain, ttl, qtype, speed, cache_data);
 	}

 	if (ttl < DNS_CACHE_TTL_MIN) {
@@ -139,58 +223,30 @@ int dns_cache_replace(char *domain, char *cname, int cname_ttl, int ttl, dns_typ

 	/* update cache data */
 	pthread_mutex_lock(&dns_cache_head.lock);
-	dns_cache->ttl = ttl;
-	dns_cache->qtype = qtype;
-	dns_cache->ttl = ttl;
 	dns_cache->del_pending = 0;
-	dns_cache->speed = speed;
-	time(&dns_cache->insert_time);
-	if (qtype == DNS_T_A) {
-		if (addr_len != DNS_RR_A_LEN) {
-			goto errout_unlock;
-		}
-		memcpy(dns_cache->addr, addr, DNS_RR_A_LEN);
-	} else if (qtype == DNS_T_AAAA) {
-		if (addr_len != DNS_RR_AAAA_LEN) {
-			goto errout_unlock;
-		}
-		memcpy(dns_cache->addr, addr, DNS_RR_AAAA_LEN);
-	} else {
-		goto errout_unlock;
-	}
-
-	if (cname) {
-		safe_strncpy(dns_cache->cname, cname, DNS_MAX_CNAME_LEN);
-		dns_cache->cname_ttl = cname_ttl;
-	}
-
+	dns_cache->info.ttl = ttl;
+	dns_cache->info.qtype = qtype;
+	dns_cache->info.ttl = ttl;
+	dns_cache->info.speed = speed;
+	time(&dns_cache->info.insert_time);
+	old_cache_data = dns_cache->cache_data;
+	dns_cache->cache_data = cache_data;
 	list_del_init(&dns_cache->list);
 	list_add_tail(&dns_cache->list, &dns_cache_head.cache_list);
 	pthread_mutex_unlock(&dns_cache_head.lock);

+	dns_cache_data_free(old_cache_data);
 	dns_cache_release(dns_cache);
 	return 0;
-errout_unlock:
-	pthread_mutex_unlock(&dns_cache_head.lock);
-	// errout:
-	if (dns_cache) {
-		dns_cache_release(dns_cache);
-	}
-	return -1;
 }

-int dns_cache_insert(char *domain, char *cname, int cname_ttl, int ttl, dns_type_t qtype, unsigned char *addr,
-					 int addr_len, int speed)
+int _dns_cache_insert(struct dns_cache_info *info, struct dns_cache_data *cache_data, struct list_head *head)
 {
 	uint32_t key = 0;
 	struct dns_cache *dns_cache = NULL;

-	if (dns_cache_head.size <= 0) {
-		return 0;
-	}
-
 	/* if cache already exists, free */
-	dns_cache = dns_cache_lookup(domain, qtype);
+	dns_cache = dns_cache_lookup(info->domain, info->qtype);
 	if (dns_cache) {
 		dns_cache_delete(dns_cache);
 		dns_cache_release(dns_cache);
@@ -202,50 +258,22 @@ int dns_cache_insert(char *domain, char *cname, int cname_ttl, int ttl, dns_type
 		goto errout;
 	}

-	if (ttl < DNS_CACHE_TTL_MIN) {
-		ttl = DNS_CACHE_TTL_MIN;
-	}
-
-	key = hash_string(domain);
-	key = jhash(&qtype, sizeof(qtype), key);
-	safe_strncpy(dns_cache->domain, domain, DNS_MAX_CNAME_LEN);
-	dns_cache->cname[0] = 0;
-	dns_cache->qtype = qtype;
-	dns_cache->ttl = ttl;
-	atomic_set(&dns_cache->hitnum, 3);
-	dns_cache->hitnum_update_add = DNS_CACHE_HITNUM_STEP;
-	dns_cache->del_pending = 0;
-	dns_cache->speed = speed;
+	memset(dns_cache, 0, sizeof(*dns_cache));
+	key = hash_string(info->domain);
+	key = jhash(&info->qtype, sizeof(info->qtype), key);
 	atomic_set(&dns_cache->ref, 1);
-	time(&dns_cache->insert_time);
-	if (qtype == DNS_T_A) {
-		if (addr_len != DNS_RR_A_LEN) {
-			goto errout;
-		}
-		memcpy(dns_cache->addr, addr, DNS_RR_A_LEN);
-	} else if (qtype == DNS_T_AAAA) {
-		if (addr_len != DNS_RR_AAAA_LEN) {
-			goto errout;
-		}
-		memcpy(dns_cache->addr, addr, DNS_RR_AAAA_LEN);
-	} else {
-		goto errout;
-	}
-
-	if (cname) {
-		safe_strncpy(dns_cache->cname, cname, DNS_MAX_CNAME_LEN);
-		dns_cache->cname_ttl = cname_ttl;
-	}
-
+	memcpy(&dns_cache->info, info, sizeof(*info));
+	dns_cache->del_pending = 0;
+	dns_cache->cache_data = cache_data;
 	pthread_mutex_lock(&dns_cache_head.lock);
 	hash_add(dns_cache_head.cache_hash, &dns_cache->node, key);
-	list_add_tail(&dns_cache->list, &dns_cache_head.cache_list);
+	list_add_tail(&dns_cache->list, head);
 	INIT_LIST_HEAD(&dns_cache->check_list);

 	/* Release extra cache, remove oldest cache record */
 	if (atomic_inc_return(&dns_cache_head.num) > dns_cache_head.size) {
 		struct dns_cache *del_cache;
-		del_cache = _dns_cache_first();
+		del_cache = _dns_inactive_cache_first();
 		if (del_cache) {
 			_dns_cache_remove(del_cache);
 		}
@@ -261,6 +289,33 @@ errout:
 	return -1;
 }

+int dns_cache_insert(char *domain, int ttl, dns_type_t qtype, int speed, struct dns_cache_data *cache_data)
+{
+	struct dns_cache_info info;
+
+	if (cache_data == NULL || domain == NULL) {
+		return -1;
+	}
+
+	if (dns_cache_head.size <= 0) {
+		return 0;
+	}
+
+	if (ttl < DNS_CACHE_TTL_MIN) {
+		ttl = DNS_CACHE_TTL_MIN;
+	}
+
+	info.hitnum = 3;
+	safe_strncpy(info.domain, domain, DNS_MAX_CNAME_LEN);
+	info.qtype = qtype;
+	info.ttl = ttl;
+	info.hitnum_update_add = DNS_CACHE_HITNUM_STEP;
+	info.speed = speed;
+	time(&info.insert_time);
+
+	return _dns_cache_insert(&info, cache_data, &dns_cache_head.cache_list);
+}
+
 struct dns_cache *dns_cache_lookup(char *domain, dns_type_t qtype)
 {
 	uint32_t key = 0;
@@ -280,11 +335,11 @@ struct dns_cache *dns_cache_lookup(char *domain, dns_type_t qtype)
 	pthread_mutex_lock(&dns_cache_head.lock);
 	hash_for_each_possible(dns_cache_head.cache_hash, dns_cache, node, key)
 	{
-		if (dns_cache->qtype != qtype) {
+		if (dns_cache->info.qtype != qtype) {
 			continue;
 		}

-		if (strncmp(domain, dns_cache->domain, DNS_MAX_CNAME_LEN) != 0) {
+		if (strncmp(domain, dns_cache->info.domain, DNS_MAX_CNAME_LEN) != 0) {
 			continue;
 		}

@@ -294,7 +349,7 @@ struct dns_cache *dns_cache_lookup(char *domain, dns_type_t qtype)

 	if (dns_cache_ret) {
 		/* Return NULL if the cache times out */
-		if (dns_cache_head.enable_inactive == 0 && (now - dns_cache_ret->insert_time > dns_cache_ret->ttl)) {
+		if (dns_cache_head.enable_inactive == 0 && (now - dns_cache_ret->info.insert_time > dns_cache_ret->info.ttl)) {
 			_dns_cache_remove(dns_cache_ret);
 			dns_cache_ret = NULL;
 		} else {
@@ -313,7 +368,7 @@ int dns_cache_get_ttl(struct dns_cache *dns_cache)
 	int ttl = 0;
 	time(&now);

-	ttl = dns_cache->insert_time + dns_cache->ttl - now;
+	ttl = dns_cache->info.insert_time + dns_cache->info.ttl - now;
 	if (ttl < 0) {
 		return 0;
 	}
@@ -321,6 +376,11 @@ int dns_cache_get_ttl(struct dns_cache *dns_cache)
 	return ttl;
 }

+struct dns_cache_data *dns_cache_get_data(struct dns_cache *dns_cache)
+{
+	return dns_cache->cache_data;
+}
+
 void dns_cache_delete(struct dns_cache *dns_cache)
 {
 	pthread_mutex_lock(&dns_cache_head.lock);
@@ -330,15 +390,14 @@ void dns_cache_delete(struct dns_cache *dns_cache)

 int dns_cache_hitnum_dec_get(struct dns_cache *dns_cache)
 {
-	int hitnum = 0;
 	pthread_mutex_lock(&dns_cache_head.lock);
-	hitnum = atomic_dec_return(&dns_cache->hitnum);
-	if (dns_cache->hitnum_update_add > DNS_CACHE_HITNUM_STEP) {
-		dns_cache->hitnum_update_add--;
+	dns_cache->info.hitnum--;
+	if (dns_cache->info.hitnum_update_add > DNS_CACHE_HITNUM_STEP) {
+		dns_cache->info.hitnum_update_add--;
 	}
 	pthread_mutex_unlock(&dns_cache_head.lock);

-	return hitnum;
+	return dns_cache->info.hitnum;
 }

 void dns_cache_update(struct dns_cache *dns_cache)
@@ -347,13 +406,13 @@ void dns_cache_update(struct dns_cache *dns_cache)
 	if (!list_empty(&dns_cache->list)) {
 		list_del_init(&dns_cache->list);
 		list_add_tail(&dns_cache->list, &dns_cache_head.cache_list);
-		atomic_add(dns_cache->hitnum_update_add, &dns_cache->hitnum);
-		if (atomic_read(&dns_cache->hitnum) > DNS_CACHE_MAX_HITNUM) {
-			atomic_set(&dns_cache->hitnum, DNS_CACHE_MAX_HITNUM);
+		dns_cache->info.hitnum += dns_cache->info.hitnum_update_add;
+		if (dns_cache->info.hitnum > DNS_CACHE_MAX_HITNUM) {
+			dns_cache->info.hitnum = DNS_CACHE_MAX_HITNUM;
 		}

-		if (dns_cache->hitnum_update_add < DNS_CACHE_HITNUM_STEP_MAX) {
-			dns_cache->hitnum_update_add++;
+		if (dns_cache->info.hitnum_update_add < DNS_CACHE_HITNUM_STEP_MAX) {
+			dns_cache->info.hitnum_update_add++;
 		}
 	}
 	pthread_mutex_unlock(&dns_cache_head.lock);
@@ -367,7 +426,7 @@ void _dns_cache_remove_expired_ttl(time_t *now)

 	list_for_each_entry_safe(dns_cache, tmp, &dns_cache_head.inactive_list, list)
 	{
-		ttl = dns_cache->insert_time + dns_cache->ttl - *now;
+		ttl = dns_cache->info.insert_time + dns_cache->info.ttl - *now;
 		if (ttl > 0) {
 			continue;
 		}
@@ -396,7 +455,7 @@ void dns_cache_invalidate(dns_cache_preinvalid_callback callback, int ttl_pre)
 	pthread_mutex_lock(&dns_cache_head.lock);
 	list_for_each_entry_safe(dns_cache, tmp, &dns_cache_head.cache_list, list)
 	{
-		ttl = dns_cache->insert_time + dns_cache->ttl - now;
+		ttl = dns_cache->info.insert_time + dns_cache->info.ttl - now;
 		if (ttl > 0 && ttl < ttl_pre) {
 			/* If the TTL time is in the pre-timeout range, call callback function */
 			if (callback && dns_cache->del_pending == 0) {
@@ -432,6 +491,216 @@ void dns_cache_invalidate(dns_cache_preinvalid_callback callback, int ttl_pre)
 	}
 }

+static int _dns_cache_read_record(int fd, uint32_t cache_number)
+{
+
+	int i = 0;
+	int ret = 0;
+	struct dns_cache_record cache_record;
+	struct dns_cache_data_head data_head;
+	struct dns_cache_data *cache_data = NULL;
+	struct list_head *head = NULL;
+
+	for (i = 0; i < cache_number; i++) {
+		ret = read(fd, &cache_record, sizeof(cache_record));
+		if (ret != sizeof(cache_record)) {
+			tlog(TLOG_ERROR, "read cache failed, %s", strerror(errno));
+			goto errout;
+		}
+
+		if (cache_record.magic != MAGIC_CACHE_DATA) {
+			tlog(TLOG_ERROR, "magic is invalid.");
+			goto errout;
+		}
+
+		if (cache_record.type == CACHE_RECORD_TYPE_ACTIVE) {
+			head = &dns_cache_head.cache_list;
+		} else {
+			head = &dns_cache_head.inactive_list;
+		}
+
+		ret = read(fd, &data_head, sizeof(data_head));
+		if (ret != sizeof(data_head)) {
+			tlog(TLOG_ERROR, "read data head failed, %s", strerror(errno));
+			goto errout;
+		}
+
+		if (data_head.size > 1024 * 8) {
+			tlog(TLOG_ERROR, "data may invalid, skip load cache.");
+			goto errout;
+		}
+
+		cache_data = malloc(data_head.size + sizeof(data_head));
+		if (cache_data == NULL) {
+			tlog(TLOG_ERROR, "malloc cache data failed %s", strerror(errno));
+			goto errout;
+		}
+
+		memcpy(&cache_data->head, &data_head, sizeof(data_head));
+		ret = read(fd, cache_data->data, data_head.size);
+		if (ret != data_head.size) {
+			tlog(TLOG_ERROR, "read cache data failed, %s", strerror(errno));
+			goto errout;
+		}
+
+		if (_dns_cache_insert(&cache_record.info, cache_data, head) != 0) {
+			tlog(TLOG_ERROR, "insert cache data failed.");
+			cache_data = NULL;
+			goto errout;
+		}
+
+		cache_data = NULL;
+	}
+
+	return 0;
+errout:
+	if (cache_data) {
+		free(cache_data);
+	}
+	return -1;
+}
+
+int dns_cache_load(const char *file)
+{
+	int fd = -1;
+	int ret = 0;
+	fd = open(file, O_RDONLY);
+	if (fd < 0) {
+		return 0;
+	}
+
+	struct dns_cache_file cache_file;
+	ret = read(fd, &cache_file, sizeof(cache_file));
+	if (ret != sizeof(cache_file)) {
+		tlog(TLOG_ERROR, "read cache head failed.");
+		goto errout;
+	}
+
+	if (cache_file.magic != MAGIC_NUMBER) {
+		tlog(TLOG_ERROR, "cache file is invalid.");
+		goto errout;
+	}
+
+	if (strncmp(cache_file.version, __TIMESTAMP__, DNS_CACHE_VERSION_LEN) != 0) {
+		tlog(TLOG_WARN, "cache version is different, skip load cache.");
+		goto errout;
+	}
+
+	if (_dns_cache_read_record(fd, cache_file.cache_number) != 0) {
+		goto errout;
+	}
+
+	close(fd);
+	return 0;
+errout:
+	if (fd > 0) {
+		close(fd);
+	}
+
+	return -1;
+}
+
+static int _dns_cache_write_record(int fd, uint32_t *cache_number, enum CACHE_RECORD_TYPE type, struct list_head *head)
+{
+	struct dns_cache *dns_cache = NULL;
+	struct dns_cache *tmp = NULL;
+	struct dns_cache_record cache_record;
+
+	pthread_mutex_lock(&dns_cache_head.lock);
+	list_for_each_entry_safe_reverse(dns_cache, tmp, head, list)
+	{
+		cache_record.magic = MAGIC_CACHE_DATA;
+		cache_record.type = type;
+		memcpy(&cache_record.info, &dns_cache->info, sizeof(struct dns_cache_info));
+		int ret = write(fd, &cache_record, sizeof(cache_record));
+		if (ret != sizeof(cache_record)) {
+			tlog(TLOG_ERROR, "write cache failed, %s", strerror(errno));
+			goto errout;
+		}
+
+		struct dns_cache_data *cache_data = dns_cache->cache_data;
+		ret = write(fd, cache_data, sizeof(*cache_data) + cache_data->head.size);
+		if (ret != sizeof(*cache_data) + cache_data->head.size) {
+			tlog(TLOG_ERROR, "write cache data failed, %s", strerror(errno));
+			goto errout;
+		}
+
+		(*cache_number)++;
+	}
+
+	pthread_mutex_unlock(&dns_cache_head.lock);
+	return 0;
+
+errout:
+	pthread_mutex_unlock(&dns_cache_head.lock);
+	return -1;
+}
+
+static int _dns_cache_write_records(int fd, uint32_t *cache_number)
+{
+
+	if (_dns_cache_write_record(fd, cache_number, CACHE_RECORD_TYPE_ACTIVE, &dns_cache_head.cache_list) != 0) {
+		return -1;
+	}
+
+	if (_dns_cache_write_record(fd, cache_number, CACHE_RECORD_TYPE_INACTIVE, &dns_cache_head.inactive_list) != 0) {
+		return -1;
+	}
+
+	return 0;
+}
+
+int dns_cache_save(const char *file)
+{
+	int fd = -1;
+	uint32_t cache_number = 0;
+	tlog(TLOG_DEBUG, "write cache file %s", file);
+
+	fd = open(file, O_TRUNC | O_CREAT | O_WRONLY, 0640);
+	if (fd < 0) {
+		tlog(TLOG_ERROR, "create file %s failed, %s", file, strerror(errno));
+		goto errout;
+	}
+
+	struct dns_cache_file cache_file;
+	memset(&cache_file, 0, sizeof(cache_file));
+	cache_file.magic = MAGIC_NUMBER;
+	safe_strncpy(cache_file.version, __TIMESTAMP__, DNS_CACHE_VERSION_LEN);
+	cache_file.cache_number = 0;
+
+	if (lseek(fd, sizeof(cache_file), SEEK_SET) < 0) {
+		tlog(TLOG_ERROR, "seek file %s failed, %s", file, strerror(errno));
+		goto errout;
+	}
+
+	if (_dns_cache_write_records(fd, &cache_number) != 0) {
+		tlog(TLOG_ERROR, "write record to file %s failed.", file);
+		goto errout;
+	}
+
+	if (lseek(fd, 0, SEEK_SET) < 0) {
+		tlog(TLOG_ERROR, "seek file %s failed, %s", file, strerror(errno));
+		goto errout;
+	}
+
+	cache_file.cache_number = cache_number;
+	if (write(fd, &cache_file, sizeof(cache_file)) != sizeof(cache_file)) {
+		tlog(TLOG_ERROR, "write file head %s failed, %s, %d", file, strerror(errno), fd);
+		goto errout;
+	}
+
+	tlog(TLOG_DEBUG, "wrote total %d records.", cache_number);
+
+	close(fd);
+	return 0;
+errout:
+	if (fd > 0) {
+		close(fd);
+	}
+
+	return -1;
+}
+
 void dns_cache_destroy(void)
 {
 	struct dns_cache *dns_cache = NULL;
--- a/src/dns_cache.h
+++ b/src/dns_cache.h
@@ -32,36 +32,100 @@ extern "C" {
 #endif

 #define DNS_CACHE_TTL_MIN 30
+#define DNS_CACHE_VERSION_LEN 32
+#define MAGIC_NUMBER 0x6548634163536e44
+#define MAGIC_CACHE_DATA 0x44615461
+
+enum CACHE_TYPE {
+	CACHE_TYPE_NONE,
+	CACHE_TYPE_ADDR,
+	CACHE_TYPE_PACKET,
+};
+
+enum CACHE_RECORD_TYPE {
+	CACHE_RECORD_TYPE_ACTIVE,
+	CACHE_RECORD_TYPE_INACTIVE,
+};
+
+struct dns_cache_data_head {
+	uint32_t cache_flag;
+	enum CACHE_TYPE cache_type;
+	size_t size;
+};
+
+struct dns_cache_data {
+	struct dns_cache_data_head head;
+	unsigned char data[0];
+};
+
+struct dns_cache_addr {
+	struct dns_cache_data_head head;
+	struct dns_cache_addr_data {
+		unsigned int cname_ttl;
+		char cname[DNS_MAX_CNAME_LEN];
+		union {
+			unsigned char ipv4_addr[DNS_RR_A_LEN];
+			unsigned char ipv6_addr[DNS_RR_AAAA_LEN];
+			unsigned char addr[0];
+		};
+	} addr_data;
+};
+
+struct dns_cache_packet {
+	struct dns_cache_data_head head;
+	unsigned char data[0];
+};
+
+struct dns_cache_info {
+	char domain[DNS_MAX_CNAME_LEN];
+	int ttl;
+	int hitnum;
+	int speed;
+	int hitnum_update_add;
+	time_t insert_time;
+	dns_type_t qtype;
+};
+
+struct dns_cache_record {
+	uint32_t magic;
+	enum CACHE_RECORD_TYPE type;
+	struct dns_cache_info info;
+};

 struct dns_cache {
 	struct hlist_node node;
 	struct list_head list;
 	struct list_head check_list;
+
 	atomic_t ref;
-	char domain[DNS_MAX_CNAME_LEN];
-	char cname[DNS_MAX_CNAME_LEN];
-	unsigned int cname_ttl;
-	unsigned int ttl;
-	int speed;
-	atomic_t hitnum;
-	int hitnum_update_add;
 	int del_pending;
-	time_t insert_time;
-	dns_type_t qtype;
-	union {
-		unsigned char ipv4_addr[DNS_RR_A_LEN];
-		unsigned char ipv6_addr[DNS_RR_AAAA_LEN];
-		unsigned char addr[0];
-	};
+
+	struct dns_cache_info info;
+	struct dns_cache_data *cache_data;
 };

+struct dns_cache_file {
+	uint64_t magic;
+	char version[DNS_CACHE_VERSION_LEN];
+	uint32_t cache_number;
+};
+
+enum CACHE_TYPE dns_cache_data_type(struct dns_cache_data *cache_data);
+
+uint32_t dns_cache_get_cache_flag(struct dns_cache_data *cache_data);
+
+void dns_cache_data_free(struct dns_cache_data *data);
+
+struct dns_cache_data *dns_cache_new_data_addr(uint32_t cache_flag, char *cname, int cname_ttl, unsigned char *addr,
+											   int addr_len);
+
+struct dns_cache_data *dns_cache_new_data_packet(uint32_t cache_flag, void *packet, size_t packet_len);
+
 int dns_cache_init(int size, int enable_inactive, int inactive_list_expired);

-int dns_cache_replace(char *domain, char *cname, int cname_ttl, int ttl, dns_type_t qtype, unsigned char *addr,
-					  int addr_len, int speed);
+int dns_cache_replace(char *domain, int ttl, dns_type_t qtype, int speed, struct dns_cache_data *cache_data);

-int dns_cache_insert(char *domain, char *cname, int cname_ttl, int ttl, dns_type_t qtype, unsigned char *addr,
-					 int addr_len, int speed);
+int dns_cache_insert(char *domain, int ttl, dns_type_t qtype, int speed, struct dns_cache_data *cache_data);

 struct dns_cache *dns_cache_lookup(char *domain, dns_type_t qtype);

@@ -81,8 +145,14 @@ void dns_cache_invalidate(dns_cache_preinvalid_callback callback, int ttl_pre);

 int dns_cache_get_ttl(struct dns_cache *dns_cache);

+struct dns_cache_data *dns_cache_get_data(struct dns_cache *dns_cache);
+
 void dns_cache_destroy(void);

+int dns_cache_load(const char *file);
+
+int dns_cache_save(const char *file);
+
 #ifdef __cpluscplus
 }
 #endif
--- a/src/dns_client.c
+++ b/src/dns_client.c
@@ -105,8 +105,10 @@ struct dns_server_info {
 	int ttl;
 	int ttl_range;
 	SSL *ssl;
+	int ssl_write_len;
 	SSL_CTX *ssl_ctx;
 	SSL_SESSION *ssl_session;
+	pthread_mutex_t lock;
 	char skip_check_cert;
 	dns_server_status status;

@@ -248,6 +250,69 @@ static LIST_HEAD(pending_servers);
 static pthread_mutex_t pending_server_mutex = PTHREAD_MUTEX_INITIALIZER;
 static int dns_client_has_bootstrap_dns = 0;

+int _ssl_read(struct dns_server_info *server, void *buff, int num)
+{
+	int ret = 0;
+	pthread_mutex_lock(&server->lock);
+	ret = SSL_read(server->ssl, buff, num);
+	pthread_mutex_unlock(&server->lock);
+	return ret;
+}
+
+int _ssl_write(struct dns_server_info *server, const void *buff, int num)
+{
+	int ret = 0;
+	pthread_mutex_lock(&server->lock);
+	ret = SSL_write(server->ssl, buff, num);
+	pthread_mutex_unlock(&server->lock);
+	return ret;
+}
+
+int _ssl_shutdown(struct dns_server_info *server)
+{
+	int ret = 0;
+	pthread_mutex_lock(&server->lock);
+	ret = SSL_shutdown(server->ssl);
+	pthread_mutex_unlock(&server->lock);
+	return ret;
+}
+
+int _ssl_get_error(struct dns_server_info *server, int ret)
+{
+	int err = 0;
+	pthread_mutex_lock(&server->lock);
+	err = SSL_get_error(server->ssl, ret);
+	pthread_mutex_unlock(&server->lock);
+	return err;
+}
+
+int _ssl_do_handshake(struct dns_server_info *server)
+{
+	int err = 0;
+	pthread_mutex_lock(&server->lock);
+	err = SSL_do_handshake(server->ssl);
+	pthread_mutex_unlock(&server->lock);
+	return err;
+}
+
+int _ssl_session_reused(struct dns_server_info *server)
+{
+	int err = 0;
+	pthread_mutex_lock(&server->lock);
+	err = SSL_session_reused(server->ssl);
+	pthread_mutex_unlock(&server->lock);
+	return err;
+}
+
+SSL_SESSION *_ssl_get1_session(struct dns_server_info *server)
+{
+	SSL_SESSION *ret = 0;
+	pthread_mutex_lock(&server->lock);
+	ret = SSL_get1_session(server->ssl);
+	pthread_mutex_unlock(&server->lock);
+	return ret;
+}
+
 const char *_dns_server_get_type_string(dns_server_type_t type)
 {
 	const char *type_str = "";
@@ -836,6 +901,7 @@ static int _dns_client_server_add(char *server_ip, char *server_host, int port,
 	server_info->ttl = ttl;
 	server_info->ttl_range = 0;
 	server_info->skip_check_cert = skip_check_cert;
+	pthread_mutex_init(&server_info->lock, NULL);
 	memcpy(&server_info->flags, flags, sizeof(server_info->flags));

 	/* exclude this server from default group */
@@ -861,6 +927,7 @@ static int _dns_client_server_add(char *server_ip, char *server_host, int port,

 		SSL_CTX_set_options(server_info->ssl_ctx, SSL_OP_ALL | SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION);
 		SSL_CTX_set_session_cache_mode(server_info->ssl_ctx, SSL_SESS_CACHE_CLIENT);
+		SSL_CTX_sess_set_cache_size(server_info->ssl_ctx, 32);
 		if (_dns_client_set_trusted_cert(server_info->ssl_ctx) != 0) {
 			tlog(TLOG_WARN, "disable check certificate for %s.", server_info->ip);
 			server_info->skip_check_cert = 1;
@@ -914,6 +981,7 @@ errout:
 			server_info->ssl_ctx = NULL;
 		}

+		pthread_mutex_destroy(&server_info->lock);
 		free(server_info);
 	}

@@ -932,9 +1000,12 @@ static void _dns_client_close_socket(struct dns_server_info *server_info)

 	if (server_info->ssl) {
 		/* Shutdown ssl */
-		SSL_shutdown(server_info->ssl);
+		if (server_info->status == DNS_SERVER_STATUS_CONNECTED) {
+			_ssl_shutdown(server_info);
+		}
 		SSL_free(server_info->ssl);
 		server_info->ssl = NULL;
+		server_info->ssl_write_len = -1;
 	}

 	/* remove fd from epoll */
@@ -949,6 +1020,36 @@ static void _dns_client_close_socket(struct dns_server_info *server_info)
 	tlog(TLOG_DEBUG, "server %s closed.", server_info->ip);
 }

+static void _dns_client_shutdown_socket(struct dns_server_info *server_info)
+{
+	if (server_info->fd <= 0) {
+		return;
+	}
+
+	switch (server_info->type) {
+	case DNS_SERVER_UDP:
+		return;
+		break;
+	case DNS_SERVER_TCP:
+		if (server_info->fd > 0) {
+			shutdown(server_info->fd, SHUT_RDWR);
+		}
+		break;
+	case DNS_SERVER_TLS:
+	case DNS_SERVER_HTTPS:
+		if (server_info->ssl) {
+			/* Shutdown ssl */
+			if (server_info->status == DNS_SERVER_STATUS_CONNECTED) {
+				_ssl_shutdown(server_info);
+			}
+			shutdown(server_info->fd, SHUT_RDWR);
+		}
+		break;
+	default:
+		break;
+	}
+}
+
 static void _dns_client_server_close(struct dns_server_info *server_info)
 {
 	/* stop ping task */
@@ -980,6 +1081,7 @@ static void _dns_client_server_remove_all(void)
 	{
 		list_del(&server_info->list);
 		_dns_client_server_close(server_info);
+		pthread_mutex_destroy(&server_info->lock);
 		free(server_info);
 	}
 	pthread_mutex_unlock(&client.server_list_lock);
@@ -1433,7 +1535,7 @@ static int _dns_client_recv(struct dns_server_info *server_info, unsigned char *
 	}

 	_dns_client_query_release(query);
-	return ret;
+	return 0;
 }

 static int _dns_client_create_socket_udp(struct dns_server_info *server_info)
@@ -1524,6 +1626,9 @@ static int _DNS_client_create_socket_tcp(struct dns_server_info *server_info)
 		}
 	}

+	server_info->fd = fd;
+	server_info->status = DNS_SERVER_STATUS_CONNECTING;
+
 	memset(&event, 0, sizeof(event));
 	event.events = EPOLLIN | EPOLLOUT;
 	event.data.ptr = server_info;
@@ -1532,17 +1637,19 @@ static int _DNS_client_create_socket_tcp(struct dns_server_info *server_info)
 		return -1;
 	}

-	server_info->fd = fd;
-	server_info->status = DNS_SERVER_STATUS_CONNECTING;
-
 	tlog(TLOG_DEBUG, "tcp server %s connecting.\n", server_info->ip);

 	return 0;
 errout:
+	if (server_info->fd > 0) {
+		server_info->fd = -1;
+	}
+
+	server_info->status = DNS_SERVER_STATUS_INIT;
+
 	if (fd > 0) {
 		close(fd);
 	}
-
 	return -1;
 }

@@ -1617,6 +1724,11 @@ static int _DNS_client_create_socket_tls(struct dns_server_info *server_info, ch
 		SSL_set_tlsext_host_name(ssl, hostname);
 	}

+	server_info->fd = fd;
+	server_info->ssl = ssl;
+	server_info->ssl_write_len = -1;
+	server_info->status = DNS_SERVER_STATUS_CONNECTING;
+
 	memset(&event, 0, sizeof(event));
 	event.events = EPOLLIN | EPOLLOUT;
 	event.data.ptr = server_info;
@@ -1625,14 +1737,20 @@ static int _DNS_client_create_socket_tls(struct dns_server_info *server_info, ch
 		goto errout;
 	}

-	server_info->fd = fd;
-	server_info->ssl = ssl;
-	server_info->status = DNS_SERVER_STATUS_CONNECTING;
-
 	tlog(TLOG_DEBUG, "tls server %s connecting.\n", server_info->ip);

 	return 0;
 errout:
+	if (server_info->fd > 0) {
+		server_info->fd = -1;
+	}
+
+	if (server_info->ssl) {
+		server_info->ssl = NULL;
+	}
+
+	server_info->status = DNS_SERVER_STATUS_INIT;
+
 	if (fd > 0) {
 		close(fd);
 	}
@@ -1731,28 +1849,28 @@ static int _dns_client_process_udp(struct dns_server_info *server_info, struct e
 	return 0;
 }

-static int _dns_client_socket_ssl_send(SSL *ssl, const void *buf, int num)
+static int _dns_client_socket_ssl_send(struct dns_server_info *server, const void *buf, int num)
 {
 	int ret = 0;
 	int ssl_ret = 0;
 	unsigned long ssl_err = 0;

-	if (ssl == NULL) {
+	if (server->ssl == NULL) {
 		errno = EINVAL;
 		return -1;
 	}

-	ret = SSL_write(ssl, buf, num);
+	ret = _ssl_write(server, buf, num);
 	if (ret > 0) {
 		return ret;
 	}

-	ssl_ret = SSL_get_error(ssl, ret);
+	ssl_ret = _ssl_get_error(server, ret);
 	switch (ssl_ret) {
 	case SSL_ERROR_NONE:
-	case SSL_ERROR_ZERO_RETURN:
 		return 0;
 		break;
+	case SSL_ERROR_ZERO_RETURN:
 	case SSL_ERROR_WANT_READ:
 		errno = EAGAIN;
 		ret = -1;
@@ -1765,7 +1883,8 @@ static int _dns_client_socket_ssl_send(SSL *ssl, const void *buf, int num)
 		ssl_err = ERR_get_error();
 		int ssl_reason = ERR_GET_REASON(ssl_err);
 		if (ssl_reason == SSL_R_UNINITIALIZED || ssl_reason == SSL_R_PROTOCOL_IS_SHUTDOWN ||
-			ssl_reason == SSL_R_BAD_LENGTH || ssl_reason == SSL_R_SHUTDOWN_WHILE_IN_INIT) {
+			ssl_reason == SSL_R_BAD_LENGTH || ssl_reason == SSL_R_SHUTDOWN_WHILE_IN_INIT ||
+			ssl_reason == SSL_R_BAD_WRITE_RETRY) {
 			errno = EAGAIN;
 			return -1;
 		}
@@ -1786,23 +1905,23 @@ static int _dns_client_socket_ssl_send(SSL *ssl, const void *buf, int num)
 	return ret;
 }

-static int _dns_client_socket_ssl_recv(SSL *ssl, void *buf, int num)
+static int _dns_client_socket_ssl_recv(struct dns_server_info *server, void *buf, int num)
 {
 	int ret = 0;
 	int ssl_ret = 0;
 	unsigned long ssl_err = 0;

-	if (ssl == NULL) {
+	if (server->ssl == NULL) {
 		errno = EFAULT;
 		return -1;
 	}

-	ret = SSL_read(ssl, buf, num);
+	ret = _ssl_read(server, buf, num);
 	if (ret >= 0) {
 		return ret;
 	}

-	ssl_ret = SSL_get_error(ssl, ret);
+	ssl_ret = _ssl_get_error(server, ret);
 	switch (ssl_ret) {
 	case SSL_ERROR_NONE:
 	case SSL_ERROR_ZERO_RETURN:
@@ -1828,11 +1947,15 @@ static int _dns_client_socket_ssl_recv(SSL *ssl, void *buf, int num)
 			return 0;
 		}

-		tlog(TLOG_ERROR, "SSL read fail error no: %s(%ld)\n", ERR_reason_error_string(ssl_err), ssl_err);
+		tlog(TLOG_ERROR, "SSL read fail error no: %s(%lx)\n", ERR_reason_error_string(ssl_err), ssl_err);
 		errno = EFAULT;
 		ret = -1;
 		break;
 	case SSL_ERROR_SYSCALL:
+		if (errno == 0) {
+			return 0;
+		}
+
 		if (errno != ECONNRESET) {
 			tlog(TLOG_INFO, "SSL syscall failed, %s ", strerror(errno));
 		}
@@ -1854,7 +1977,18 @@ static int _dns_client_socket_send(struct dns_server_info *server_info)
 	} else if (server_info->type == DNS_SERVER_TCP) {
 		return send(server_info->fd, server_info->send_buff.data, server_info->send_buff.len, MSG_NOSIGNAL);
 	} else if (server_info->type == DNS_SERVER_TLS || server_info->type == DNS_SERVER_HTTPS) {
-		return _dns_client_socket_ssl_send(server_info->ssl, server_info->send_buff.data, server_info->send_buff.len);
+		int write_len = server_info->send_buff.len;
+		if (server_info->ssl_write_len > 0) {
+			write_len = server_info->ssl_write_len;
+			server_info->ssl_write_len = -1;
+		}
+		int ret = _dns_client_socket_ssl_send(server_info, server_info->send_buff.data, write_len);
+		if (ret != 0) {
+			if (errno == EAGAIN) {
+				server_info->ssl_write_len = write_len;
+			}
+		}
+		return ret;
 	} else {
 		return -1;
 	}
@@ -1868,7 +2002,7 @@ static int _dns_client_socket_recv(struct dns_server_info *server_info)
 		return recv(server_info->fd, server_info->recv_buff.data + server_info->recv_buff.len,
 					DNS_TCP_BUFFER - server_info->recv_buff.len, 0);
 	} else if (server_info->type == DNS_SERVER_TLS || server_info->type == DNS_SERVER_HTTPS) {
-		return _dns_client_socket_ssl_recv(server_info->ssl, server_info->recv_buff.data + server_info->recv_buff.len,
+		return _dns_client_socket_ssl_recv(server_info, server_info->recv_buff.data + server_info->recv_buff.len,
 										   DNS_TCP_BUFFER - server_info->recv_buff.len);
 	} else {
 		return -1;
@@ -1986,6 +2120,11 @@ static int _dns_client_process_tcp(struct dns_server_info *server_info, struct e
 				goto errout;
 			}

+			if (errno == ETIMEDOUT) {
+				tlog(TLOG_INFO, "recv failed, server %s:%d, %s\n", server_info->ip, server_info->port, strerror(errno));
+				goto errout;
+			}
+
 			tlog(TLOG_ERROR, "recv failed, server %s:%d, %s\n", server_info->ip, server_info->port, strerror(errno));
 			goto errout;
 		}
@@ -2115,7 +2254,8 @@ static int _dns_client_tls_matchName(const char *host, const char *pattern, int
 	return match;
 }

-static int _dns_client_tls_get_cert_CN(X509 *cert, char *cn, int max_cn_len) {
+static int _dns_client_tls_get_cert_CN(X509 *cert, char *cn, int max_cn_len)
+{
 	X509_NAME *cert_name = NULL;

 	cert_name = X509_get_subject_name(cert);
@@ -2153,8 +2293,10 @@ static int _dns_client_tls_verify(struct dns_server_info *server_info)
 		return -1;
 	}

+	pthread_mutex_lock(&server_info->lock);
 	cert = SSL_get_peer_certificate(server_info->ssl);
 	if (cert == NULL) {
+		pthread_mutex_unlock(&server_info->lock);
 		tlog(TLOG_ERROR, "get peer certificate failed.");
 		return -1;
 	}
@@ -2162,6 +2304,7 @@ static int _dns_client_tls_verify(struct dns_server_info *server_info)
 	if (server_info->skip_check_cert == 0) {
 		long res = SSL_get_verify_result(server_info->ssl);
 		if (res != X509_V_OK) {
+			pthread_mutex_unlock(&server_info->lock);
 			peer_CN[0] = '\0';
 			_dns_client_tls_get_cert_CN(cert, peer_CN, sizeof(peer_CN));
 			tlog(TLOG_WARN, "peer server %s certificate verify failed", server_info->ip);
@@ -2169,6 +2312,7 @@ static int _dns_client_tls_verify(struct dns_server_info *server_info)
 			goto errout;
 		}
 	}
+	pthread_mutex_unlock(&server_info->lock);

 	if (_dns_client_tls_get_cert_CN(cert, peer_CN, sizeof(peer_CN)) != 0) {
 		tlog(TLOG_ERROR, "get cert CN failed.");
@@ -2268,12 +2412,12 @@ static int _dns_client_process_tls(struct dns_server_info *server_info, struct e

 	if (server_info->status == DNS_SERVER_STATUS_CONNECTING) {
 		/* do SSL hand shake */
-		ret = SSL_do_handshake(server_info->ssl);
+		ret = _ssl_do_handshake(server_info);
 		if (ret == 0) {
 			goto errout;
 		} else if (ret < 0) {
 			memset(&fd_event, 0, sizeof(fd_event));
-			ssl_ret = SSL_get_error(server_info->ssl, ret);
+			ssl_ret = _ssl_get_error(server_info, ret);
 			if (ssl_ret == SSL_ERROR_WANT_READ) {
 				fd_event.events = EPOLLIN;
 			} else if (ssl_ret == SSL_ERROR_WANT_WRITE) {
@@ -2302,7 +2446,7 @@ static int _dns_client_process_tls(struct dns_server_info *server_info, struct e

 		tlog(TLOG_DEBUG, "tls server %s connected.\n", server_info->ip);
 		/* Was the stored session reused? */
-		if (SSL_session_reused(server_info->ssl)) {
+		if (_ssl_session_reused(server_info)) {
 			tlog(TLOG_DEBUG, "reused session");
 		} else {
 			tlog(TLOG_DEBUG, "new session");
@@ -2320,7 +2464,7 @@ static int _dns_client_process_tls(struct dns_server_info *server_info, struct e
 			}

 			/* save ssl session for next request */
-			server_info->ssl_session = SSL_get1_session(server_info->ssl);
+			server_info->ssl_session = _ssl_get1_session(server_info);
 			pthread_mutex_unlock(&client.server_list_lock);
 		}

@@ -2471,13 +2615,13 @@ static int _dns_client_send_tls(struct dns_server_info *server_info, void *packe
 		return -1;
 	}

-	send_len = _dns_client_socket_ssl_send(server_info->ssl, inpacket, len);
+	send_len = _dns_client_socket_ssl_send(server_info, inpacket, len);
 	if (send_len <= 0) {
 		if (errno == EAGAIN || errno == EPIPE || server_info->ssl == NULL) {
 			/* save data to buffer, and retry when EPOLLOUT is available */
 			return _dns_client_send_data_to_buffer(server_info, inpacket, len);
 		} else if (server_info->ssl && errno != ENOMEM) {
-			SSL_set_shutdown(server_info->ssl, SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN);
+			SSL_shutdown(server_info->ssl);
 		}
 		return -1;
 	} else if (send_len < len) {
@@ -2522,13 +2666,13 @@ static int _dns_client_send_https(struct dns_server_info *server_info, void *pac
 		return -1;
 	}

-	send_len = _dns_client_socket_ssl_send(server_info->ssl, inpacket, http_len);
+	send_len = _dns_client_socket_ssl_send(server_info, inpacket, http_len);
 	if (send_len <= 0) {
 		if (errno == EAGAIN || errno == EPIPE || server_info->ssl == NULL) {
 			/* save data to buffer, and retry when EPOLLOUT is available */
 			return _dns_client_send_data_to_buffer(server_info, inpacket, http_len);
 		} else if (server_info->ssl && errno != ENOMEM) {
-			SSL_set_shutdown(server_info->ssl, SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN);
+			_ssl_shutdown(server_info);
 		}
 		return -1;
 	} else if (send_len < http_len) {
@@ -2596,21 +2740,18 @@ static int _dns_client_send_packet(struct dns_query_struct *query, void *packet,
 					tlog(TLOG_DEBUG, "send query to %s failed, %s, type: %d", server_info->ip, strerror(send_err),
 						 server_info->type);
 					_dns_client_close_socket(server_info);
-				} else if (send_err != ENOMEM) {
-					tlog(TLOG_ERROR, "send query to %s failed, %s, type: %d", server_info->ip, strerror(send_err),
-						 server_info->type);
-				} else {
-					tlog(TLOG_DEBUG, "send query to %s failed, %s, type: %d", server_info->ip, strerror(send_err),
-						 server_info->type);
-					time_t now;
-					time(&now);
-					if (now - 5 > server_info->last_recv) {
-						server_info->recv_buff.len = 0;
-						server_info->send_buff.len = 0;
-						tlog(TLOG_DEBUG, "server %s not response, retry.", server_info->ip);
-						_dns_client_close_socket(server_info);
-					}
+					atomic_dec(&query->dns_request_sent);
+					continue;
 				}
+
+				tlog(TLOG_DEBUG, "send query to %s failed, %s, type: %d", server_info->ip, strerror(send_err),
+					 server_info->type);
+				time_t now;
+				time(&now);
+				if (now - 5 > server_info->last_recv || send_err != ENOMEM) {
+					_dns_client_shutdown_socket(server_info);
+				}
+
 				atomic_dec(&query->dns_request_sent);
 				continue;
 			}
@@ -2867,7 +3008,7 @@ static void _dns_client_add_pending_servers(void)
 		if (pending->query_v4 == 0) {
 			pending->query_v4 = 1;
 			_dns_client_server_pending_get(pending);
-			if (dns_server_query(pending->host, DNS_T_A, _dns_client_pending_server_resolve, pending) != 0) {
+			if (dns_server_query(pending->host, DNS_T_A, 0, _dns_client_pending_server_resolve, pending) != 0) {
 				_dns_client_server_pending_release_lck(pending);
 			}
 		}
@@ -2875,14 +3016,13 @@ static void _dns_client_add_pending_servers(void)
 		if (pending->query_v6 == 0) {
 			pending->query_v6 = 1;
 			_dns_client_server_pending_get(pending);
-			if (dns_server_query(pending->host, DNS_T_AAAA, _dns_client_pending_server_resolve, pending) != 0) {
+			if (dns_server_query(pending->host, DNS_T_AAAA, 0, _dns_client_pending_server_resolve, pending) != 0) {
 				_dns_client_server_pending_release_lck(pending);
 			}
 		}

 		/* if both A, AAAA has query result, select fastest IP address */
 		if (pending->has_v4 && pending->has_v6) {
-
 			if (pending->ping_time_v4 <= pending->ping_time_v6 && pending->ipv4[0]) {
 				dnsserver_ip = pending->ipv4;
 			} else {
--- a/src/dns_conf.c
+++ b/src/dns_conf.c
@@ -50,6 +50,7 @@ int dns_conf_cachesize = DEFAULT_DNS_CACHE_SIZE;
 int dns_conf_prefetch = 0;
 int dns_conf_serve_expired = 0;
 int dns_conf_serve_expired_ttl = 0;
+int dns_conf_serve_expired_reply_ttl = 5;

 /* upstream servers */
 struct dns_servers dns_conf_servers[DNS_MAX_SERVERS];
@@ -72,6 +73,9 @@ int dns_conf_log_num = 8;
 char dns_conf_ca_file[DNS_MAX_PATH];
 char dns_conf_ca_path[DNS_MAX_PATH];

+char dns_conf_cache_file[DNS_MAX_PATH];
+int dns_conf_cache_persist = 2;
+
 /* auditing */
 int dns_conf_audit_enable = 0;
 int dns_conf_audit_log_SOA;
@@ -107,6 +111,10 @@ static int _get_domain(char *value, char *domain, int max_dmain_size, char **ptr
 	char *end = NULL;
 	int len = 0;

+	if (value == NULL || domain == NULL) {
+		goto errout;
+	}
+
 	/* first field */
 	begin = strstr(value, "/");
 	if (begin == NULL) {
@@ -1354,9 +1362,12 @@ static struct config_item _config_item[] = {
 	CONF_CUSTOM("speed-check-mode", _config_speed_check_mode, NULL),
 	CONF_INT("tcp-idle-time", &dns_conf_tcp_idle_time, 0, 3600),
 	CONF_INT("cache-size", &dns_conf_cachesize, 0, CONF_INT_MAX),
+	CONF_STRING("cache-file", (char *)&dns_conf_cache_file, DNS_MAX_PATH),
+	CONF_YESNO("cache-persist", &dns_conf_cache_persist),
 	CONF_YESNO("prefetch-domain", &dns_conf_prefetch),
 	CONF_YESNO("serve-expired", &dns_conf_serve_expired),
 	CONF_INT("serve-expired-ttl", &dns_conf_serve_expired_ttl, 0, CONF_INT_MAX),
+	CONF_INT("serve-expired-reply-ttl", &dns_conf_serve_expired_reply_ttl, 0, CONF_INT_MAX),
 	CONF_YESNO("dualstack-ip-selection", &dns_conf_dualstack_ip_selection),
 	CONF_INT("dualstack-ip-selection-threshold", &dns_conf_dualstack_ip_selection_threshold, 0, 1000),
 	CONF_CUSTOM("log-level", _config_log_level, NULL),
--- a/src/dns_conf.h
+++ b/src/dns_conf.h
@@ -49,6 +49,7 @@ extern "C" {
 #define SMARTDNS_CONF_FILE "/etc/smartdns/smartdns.conf"
 #define SMARTDNS_LOG_FILE "/var/log/smartdns.log"
 #define SMARTDNS_AUDIT_FILE "/var/log/smartdns-audit.log"
+#define SMARTDNS_CACHE_FILE "/tmp/smartdns.cache"

 enum domain_rule {
 	DOMAIN_RULE_FLAGS = 0,
@@ -90,7 +91,7 @@ typedef enum {
 #define BIND_FLAG_NO_SPEED_CHECK (1 << 5)
 #define BIND_FLAG_NO_CACHE (1 << 6)
 #define BIND_FLAG_NO_DUALSTACK_SELECTION (1 << 7)
-#define BIND_FLAG_FORCE_AAAA_SOA (1 << 8) 
+#define BIND_FLAG_FORCE_AAAA_SOA (1 << 8)

 struct dns_rule_flags {
 	unsigned int flags;
@@ -204,6 +205,7 @@ extern int dns_conf_cachesize;
 extern int dns_conf_prefetch;
 extern int dns_conf_serve_expired;
 extern int dns_conf_serve_expired_ttl;
+extern int dns_conf_serve_expired_reply_ttl;
 extern struct dns_servers dns_conf_servers[DNS_MAX_SERVERS];
 extern int dns_conf_server_num;

@@ -215,6 +217,9 @@ extern int dns_conf_log_num;
 extern char dns_conf_ca_file[DNS_MAX_PATH];
 extern char dns_conf_ca_path[DNS_MAX_PATH];

+extern char dns_conf_cache_file[DNS_MAX_PATH];
+extern int dns_conf_cache_persist;
+
 extern struct dns_domain_check_order dns_conf_check_order;

 extern struct dns_server_groups dns_conf_server_groups[DNS_NAX_GROUP_NUMBER];
--- a/src/dns_server.c
+++ b/src/dns_server.c
@@ -52,6 +52,7 @@
 #define DNS_PING_SECOND_TIMEOUT (DNS_REQUEST_MAX_TIMEOUT - DNS_TCPPING_START)
 #define SOCKET_IP_TOS (IPTOS_LOWDELAY | IPTOS_RELIABILITY)
 #define SOCKET_PRIORITY (6)
+#define CACHE_AUTO_ENABLE_SIZE (1024 * 1024 * 128)

 #define RECV_ERROR_AGAIN 1
 #define RECV_ERROR_OK 0
@@ -137,6 +138,8 @@ struct dns_request {
 	atomic_t refcnt;

 	struct dns_server_conn_head *conn;
+	uint32_t server_flags;
+
 	/* dns request list */
 	struct list_head list;

@@ -206,7 +209,7 @@ static struct dns_server server;

 static tlog_log *dns_audit;

-static int _dns_server_prefetch_request(char *domain, dns_type_t qtype);
+static int _dns_server_prefetch_request(char *domain, dns_type_t qtype, uint32_t server_flags);

 static int _dns_server_forward_request(unsigned char *inpacket, int inpacket_len)
 {
@@ -216,17 +219,27 @@ static int _dns_server_forward_request(unsigned char *inpacket, int inpacket_len

 static int _dns_server_has_bind_flag(struct dns_request *request, uint32_t flag)
 {
-	if (request->conn == NULL) {
-		return -1;
-	}
-
-	if (request->conn->server_flags & flag) {
+	if (request->server_flags & flag) {
 		return 0;
 	}

 	return -1;
 }

+static int _dns_server_get_conf_ttl(int ttl)
+{
+	if (dns_conf_rr_ttl > 0) {
+		return dns_conf_rr_ttl;
+	}
+
+	if (dns_conf_rr_ttl_max > 0 && ttl > dns_conf_rr_ttl_max) {
+		ttl = dns_conf_rr_ttl_max;
+	} else if (dns_conf_rr_ttl_min > 0 && ttl < dns_conf_rr_ttl_min) {
+		ttl = dns_conf_rr_ttl_min;
+	}
+	return ttl;
+}
+
 static int _dns_server_epoll_ctl(struct dns_server_conn_head *head, int op, uint32_t events)
 {
 	struct epoll_event event;
@@ -478,7 +491,7 @@ static int _dns_server_reply_udp(struct dns_request *request, struct dns_server_
 	send_len =
 		sendto(udpserver->head.fd, inpacket, inpacket_len, 0, (struct sockaddr *)&request->addr, request->addr_len);
 	if (send_len != inpacket_len) {
-		tlog(TLOG_ERROR, "send failed.");
+		tlog(TLOG_ERROR, "send failed, %s", strerror(errno));
 		return -1;
 	}

@@ -692,10 +705,47 @@ static int _dns_setup_ipset(struct dns_request *request)
 	return ret;
 }

+static int _dns_server_request_update_cache(struct dns_request *request, dns_type_t qtype,
+											struct dns_cache_data *cache_data)
+{
+	int ttl;
+	int speed = 0;
+
+	if (qtype == DNS_T_A) {
+		ttl = _dns_server_get_conf_ttl(request->ttl_v4);
+		speed = request->ping_ttl_v4;
+	} else if (qtype == DNS_T_AAAA) {
+		ttl = _dns_server_get_conf_ttl(request->ttl_v6);
+		speed = request->ping_ttl_v6;
+	} else {
+		goto errout;
+	}
+
+	/* if doing prefetch, update cache only */
+	if (request->prefetch) {
+		if (dns_cache_replace(request->domain, ttl, qtype, speed, cache_data) != 0) {
+			goto errout;
+		}
+	} else {
+		/* insert result to cache */
+		if (dns_cache_insert(request->domain, ttl, qtype, speed, cache_data) != 0) {
+			goto errout;
+		}
+	}
+
+	return 0;
+errout:
+	if (cache_data) {
+		dns_cache_data_free(cache_data);
+	}
+	return -1;
+}
+
 static int _dns_server_request_complete_A(struct dns_request *request)
 {
 	char *cname = NULL;
 	int cname_ttl = 0;
+	struct dns_cache_data *cache_data = NULL;

 	if (request->has_cname) {
 		cname = request->cname;
@@ -718,23 +768,32 @@ static int _dns_server_request_complete_A(struct dns_request *request)
 		return 0;
 	}

-	/* if doing prefetch, update cache only */
-	if (request->prefetch) {
-		dns_cache_replace(request->domain, cname, cname_ttl, request->ttl_v4, DNS_T_A, request->ipv4_addr, DNS_RR_A_LEN,
-						  request->ping_ttl_v4);
-	} else {
-		/* insert result to cache */
-		dns_cache_insert(request->domain, cname, cname_ttl, request->ttl_v4, DNS_T_A, request->ipv4_addr, DNS_RR_A_LEN,
-						 request->ping_ttl_v4);
+	cache_data = dns_cache_new_data_addr(request->server_flags, cname, cname_ttl, request->ipv4_addr, DNS_RR_A_LEN);
+	if (cache_data == NULL) {
+		goto errout;
+	}
+
+	if (_dns_server_request_update_cache(request, DNS_T_A, cache_data) != 0) {
+		goto errout;
 	}

 	return 0;
+
+errout:
+	if (cache_data) {
+		dns_cache_data_free(cache_data);
+		cache_data = NULL;
+	}
+
+	return -1;
 }

 static int _dns_server_request_complete_AAAA(struct dns_request *request)
 {
+	int ret = -1;
 	char *cname = NULL;
 	int cname_ttl = 0;
+	struct dns_cache_data *cache_data = NULL;

 	if (request->has_cname) {
 		cname = request->cname;
@@ -756,13 +815,14 @@ static int _dns_server_request_complete_AAAA(struct dns_request *request)

 		/* if doing prefetch, update cache only */
 		if (_dns_server_has_bind_flag(request, BIND_FLAG_NO_CACHE) != 0) {
-			if (request->prefetch) {
-				dns_cache_replace(request->domain, cname, cname_ttl, request->ttl_v6, DNS_T_AAAA, request->ipv6_addr,
-								  DNS_RR_AAAA_LEN, request->ping_ttl_v6);
-			} else {
-				/* insert result to cache */
-				dns_cache_insert(request->domain, cname, cname_ttl, request->ttl_v6, DNS_T_AAAA, request->ipv6_addr,
-								 DNS_RR_AAAA_LEN, request->ping_ttl_v6);
+			cache_data =
+				dns_cache_new_data_addr(request->server_flags, cname, cname_ttl, request->ipv6_addr, DNS_T_AAAA);
+			if (cache_data == NULL) {
+				goto errout;
+			}
+
+			if (_dns_server_request_update_cache(request, DNS_T_AAAA, cache_data) != 0) {
+				goto errout;
 			}
 		}

@@ -778,21 +838,25 @@ static int _dns_server_request_complete_AAAA(struct dns_request *request)
 			request->ping_ttl_v6 < 0) {
 			tlog(TLOG_DEBUG, "Force IPV4 perfered.");
 			if (_dns_server_has_bind_flag(request, BIND_FLAG_NO_CACHE) != 0) {
-				if (request->prefetch) {
-					dns_cache_replace(request->domain, cname, cname_ttl, request->ttl_v4, DNS_T_A, request->ipv4_addr,
-									  DNS_RR_A_LEN, request->ping_ttl_v4);
-				} else {
-					dns_cache_insert(request->domain, cname, cname_ttl, request->ttl_v4, DNS_T_A, request->ipv4_addr,
-									 DNS_RR_A_LEN, request->ping_ttl_v4);
+				cache_data =
+					dns_cache_new_data_addr(request->server_flags, cname, cname_ttl, request->ipv4_addr, DNS_T_A);
+				if (cache_data == NULL) {
+					goto errout;
+				}
+
+				if (_dns_server_request_update_cache(request, DNS_T_A, cache_data) != 0) {
+					goto errout;
 				}
 			}

 			if (request->dualstack_selection) {
 				if (_dns_server_reply_SOA(DNS_RC_NOERROR, request) != 0) {
-					return -1;
+					ret = -1;
+					goto errout;
 				}

-				return 1;
+				ret = 1;
+				goto errout;
 			}
 		}
 	}
@@ -800,6 +864,14 @@ static int _dns_server_request_complete_AAAA(struct dns_request *request)
 	request->has_ipv4 = 0;

 	return 0;
+
+errout:
+	if (cache_data == NULL) {
+		dns_cache_data_free(cache_data);
+		cache_data = NULL;
+	}
+
+	return ret;
 }

 static int _dns_server_request_complete(struct dns_request *request)
@@ -1196,20 +1268,6 @@ static int _dns_ip_address_check_add(struct dns_request *request, unsigned char
 	return 0;
 }

-static int _dns_server_get_conf_ttl(int ttl)
-{
-	if (dns_conf_rr_ttl > 0) {
-		return dns_conf_rr_ttl;
-	}
-
-	if (dns_conf_rr_ttl_max > 0 && ttl > dns_conf_rr_ttl_max) {
-		ttl = dns_conf_rr_ttl_max;
-	} else if (dns_conf_rr_ttl_min > 0 && ttl < dns_conf_rr_ttl_min) {
-		ttl = dns_conf_rr_ttl_min;
-	}
-	return ttl;
-}
-
 static int _dns_server_ip_rule_check(struct dns_request *request, unsigned char *addr, int addr_len,
 									 dns_type_t addr_type, int result_flag)
 {
@@ -1631,6 +1689,163 @@ static int _dns_server_passthrough_rule_check(struct dns_request *request, char
 	return -1;
 }

+static int _dns_server_get_answer(struct dns_request *request, struct dns_packet *packet)
+{
+	int i = 0;
+	int j = 0;
+	int ttl = 0;
+	struct dns_rrs *rrs = NULL;
+	int rr_count = 0;
+	char name[DNS_MAX_CNAME_LEN] = {0};
+
+	for (j = 1; j < DNS_RRS_END; j++) {
+		rrs = dns_get_rrs_start(packet, j, &rr_count);
+		for (i = 0; i < rr_count && rrs; i++, rrs = dns_get_rrs_next(packet, rrs)) {
+			switch (rrs->type) {
+			case DNS_T_A: {
+				unsigned char addr[4];
+				char name[DNS_MAX_CNAME_LEN] = {0};
+
+				if (request->qtype != DNS_T_A) {
+					continue;
+				}
+
+				/* get A result */
+				dns_get_A(rrs, name, DNS_MAX_CNAME_LEN, &ttl, addr);
+				memcpy(request->ipv4_addr, addr, DNS_RR_A_LEN);
+				request->ttl_v4 = _dns_server_get_conf_ttl(ttl);
+				request->has_ipv4 = 1;
+				request->rcode = packet->head.rcode;
+			} break;
+			case DNS_T_AAAA: {
+				unsigned char addr[16];
+				char name[DNS_MAX_CNAME_LEN] = {0};
+
+				if (request->qtype != DNS_T_AAAA) {
+					/* ignore non-matched query type */
+					continue;
+				}
+				dns_get_AAAA(rrs, name, DNS_MAX_CNAME_LEN, &ttl, addr);
+				memcpy(request->ipv6_addr, addr, DNS_RR_AAAA_LEN);
+				request->ttl_v6 = _dns_server_get_conf_ttl(ttl);
+				request->has_ipv6 = 1;
+				request->rcode = packet->head.rcode;
+			} break;
+			case DNS_T_NS: {
+				char cname[DNS_MAX_CNAME_LEN];
+				dns_get_CNAME(rrs, name, DNS_MAX_CNAME_LEN, &ttl, cname, DNS_MAX_CNAME_LEN);
+				tlog(TLOG_DEBUG, "NS: %s ttl:%d cname: %s\n", name, ttl, cname);
+			} break;
+			case DNS_T_CNAME: {
+				char cname[DNS_MAX_CNAME_LEN];
+				dns_get_CNAME(rrs, name, DNS_MAX_CNAME_LEN, &ttl, cname, DNS_MAX_CNAME_LEN);
+				tlog(TLOG_DEBUG, "name:%s ttl: %d cname: %s\n", name, ttl, cname);
+				safe_strncpy(request->cname, cname, DNS_MAX_CNAME_LEN);
+				request->ttl_cname = ttl;
+				request->has_cname = 1;
+			} break;
+			case DNS_T_SOA: {
+				request->has_soa = 1;
+				request->rcode = packet->head.rcode;
+				dns_get_SOA(rrs, name, 128, &ttl, &request->soa);
+				tlog(TLOG_DEBUG,
+					 "domain: %s, qtype: %d, SOA: mname: %s, rname: %s, serial: %d, refresh: %d, retry: %d, expire: "
+					 "%d, minimum: %d",
+					 request->domain, request->qtype, request->soa.mname, request->soa.rname, request->soa.serial,
+					 request->soa.refresh, request->soa.retry, request->soa.expire, request->soa.minimum);
+				if (atomic_inc_return(&request->soa_num) >= (dns_server_num() / 2)) {
+					_dns_server_request_complete(request);
+				}
+			} break;
+			default:
+				tlog(TLOG_DEBUG, "%s, qtype: %d", name, rrs->type);
+				break;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int _dns_server_setup_ipset_packet(struct dns_request *request, struct dns_packet *packet)
+{
+	int ttl;
+	char name[DNS_MAX_CNAME_LEN] = {0};
+	int rr_count;
+	int i = 0;
+	int j = 0;
+	struct dns_rrs *rrs = NULL;
+	struct dns_ipset_rule *ipset_rule = NULL;
+	struct dns_rule_flags *rule_flags = NULL;
+
+	if (_dns_server_has_bind_flag(request, BIND_FLAG_NO_RULE_IPSET) == 0) {
+		return 0;
+	}
+	/* check ipset rule */
+	rule_flags = request->domain_rule.rules[DOMAIN_RULE_FLAGS];
+	if (rule_flags) {
+		if (rule_flags->flags & DOMAIN_FLAG_IPSET_IGNORE) {
+			return 0;
+		}
+	}
+
+	ipset_rule = request->domain_rule.rules[DOMAIN_RULE_IPSET];
+	if (ipset_rule == NULL) {
+		return 0;
+	}
+
+	for (j = 1; j < DNS_RRS_END; j++) {
+		rrs = dns_get_rrs_start(packet, j, &rr_count);
+		for (i = 0; i < rr_count && rrs; i++, rrs = dns_get_rrs_next(packet, rrs)) {
+			switch (rrs->type) {
+			case DNS_T_A: {
+				unsigned char addr[4];
+				if (request->qtype != DNS_T_A) {
+					/* ignore non-matched query type */
+					if (request->dualstack_selection == 0) {
+						break;
+					}
+				}
+				/* get A result */
+				dns_get_A(rrs, name, DNS_MAX_CNAME_LEN, &ttl, addr);
+
+				/* add IPV4 to ipset */
+				ipset_add(ipset_rule->ipsetname, addr, DNS_RR_A_LEN, request->ttl_v4 * 2);
+
+				tlog(TLOG_DEBUG, "IPSET-MATCH-PASSTHROUTH: domain: %s, ipset: %s, IP: %d.%d.%d.%d", request->domain,
+					 ipset_rule->ipsetname, addr[0], addr[1], addr[2], addr[3]);
+			} break;
+			case DNS_T_AAAA: {
+				unsigned char addr[16];
+				if (request->qtype != DNS_T_AAAA) {
+					/* ignore non-matched query type */
+					break;
+				}
+				dns_get_AAAA(rrs, name, DNS_MAX_CNAME_LEN, &ttl, addr);
+
+				/* add IPV6 to ipset */
+				if (request->has_ipv6) {
+					if (request->has_ipv4) {
+						ipset_add(ipset_rule->ipsetname, addr, DNS_RR_A_LEN, request->ttl_v4 * 2);
+					}
+					ipset_add(ipset_rule->ipsetname, addr, DNS_RR_AAAA_LEN, request->ttl_v6 * 2);
+				}
+
+				tlog(TLOG_DEBUG,
+					 "IPSET-MATCH-PASSTHROUTH: domain: %s, ipset: %s, IP: "
+					 "%.2x%.2x:%.2x%.2x:%.2x%.2x:%.2x%.2x:%.2x%.2x:%.2x%.2x:%.2x%.2x:%.2x%.2x",
+					 request->domain, ipset_rule->ipsetname, addr[0], addr[1], addr[2], addr[3], addr[4], addr[5],
+					 addr[6], addr[7], addr[8], addr[9], addr[10], addr[11], addr[12], addr[13], addr[14], addr[15]);
+			} break;
+			default:
+				break;
+			}
+		}
+	}
+
+	return 0;
+}
+
 static int _dns_server_reply_passthrouth(struct dns_request *request, struct dns_packet *packet,
 										 unsigned char *inpacket, int inpacket_len)
 {
@@ -1640,6 +1855,11 @@ static int _dns_server_reply_passthrouth(struct dns_request *request, struct dns
 		return 0;
 	}

+	_dns_server_get_answer(request, packet);
+	if (request->result_callback) {
+		_dns_result_callback(request);
+	}
+
 	if (request->conn == NULL) {
 		return 0;
 	}
@@ -1648,7 +1868,27 @@ static int _dns_server_reply_passthrouth(struct dns_request *request, struct dns
 	dns_server_update_reply_packet_id(request, inpacket, inpacket_len);
 	ret = _dns_reply_inpacket(request, inpacket, inpacket_len);

-	return ret;
+	if (packet->head.rcode != DNS_RC_NOERROR && packet->head.rcode != DNS_RC_NXDOMAIN) {
+		return ret;
+	}
+
+	if (_dns_server_has_bind_flag(request, BIND_FLAG_NO_CACHE) != 0 &&
+		(request->qtype == DNS_T_AAAA || request->qtype == DNS_T_A)) {
+		struct dns_cache_data *cache_packet = dns_cache_new_data_packet(request->server_flags, inpacket, inpacket_len);
+		if (cache_packet == NULL) {
+			return ret;
+		}
+
+		if (_dns_server_request_update_cache(request, request->qtype, cache_packet) != 0) {
+			tlog(TLOG_WARN, "update packet cache failed.");
+		}
+	}
+
+	if (_dns_server_setup_ipset_packet(request, packet) != 0) {
+		tlog(TLOG_DEBUG, "setup ipset failed.");
+	}
+
+	return 0;
 }

 static int dns_server_resolve_callback(char *domain, dns_result_type rtype, unsigned int result_flag,
@@ -1673,7 +1913,6 @@ static int dns_server_resolve_callback(char *domain, dns_result_type rtype, unsi

 			return _dns_server_reply_passthrouth(request, packet, inpacket, inpacket_len);
 		}
-
 		_dns_server_process_answer(request, domain, packet, result_flag);
 		return 0;
 	} else if (rtype == DNS_QUERY_ERR) {
@@ -1791,7 +2030,6 @@ static void _dns_server_log_rule(const char *domain, enum domain_rule rule_type,
 								 int rule_key_len)
 {
 	char rule_name[DNS_MAX_CNAME_LEN];
-
 	if (rule_key_len <= 0) {
 		return;
 	}
@@ -2026,6 +2264,128 @@ static void _dns_server_process_speed_check_rule(struct dns_request *request)
 	request->check_order_list = check_order;
 }

+static int _dns_server_get_expired_ttl_reply(struct dns_cache *dns_cache)
+{
+	int ttl = dns_cache_get_ttl(dns_cache);
+	if (ttl > 0) {
+		return ttl;
+	}
+
+	return dns_conf_serve_expired_reply_ttl;
+}
+
+static int _dns_server_process_cache_addr(struct dns_request *request, struct dns_cache *dns_cache)
+{
+	struct dns_cache_addr *cache_addr = (struct dns_cache_addr *)dns_cache_get_data(dns_cache);
+
+	if (cache_addr->head.cache_type != CACHE_TYPE_ADDR) {
+		goto errout;
+	}
+	/* Cache hits, returning results in the cache */
+	switch (request->qtype) {
+	case DNS_T_A:
+		memcpy(request->ipv4_addr, cache_addr->addr_data.ipv4_addr, DNS_RR_A_LEN);
+		request->ttl_v4 = _dns_server_get_expired_ttl_reply(dns_cache);
+		request->has_ipv4 = 1;
+		break;
+	case DNS_T_AAAA:
+		memcpy(request->ipv6_addr, cache_addr->addr_data.ipv6_addr, DNS_RR_AAAA_LEN);
+		request->ttl_v6 = _dns_server_get_expired_ttl_reply(dns_cache);
+		request->has_ipv6 = 1;
+		break;
+	default:
+		goto errout;
+		break;
+	}
+
+	if (cache_addr->addr_data.cname[0] != 0) {
+		safe_strncpy(request->cname, cache_addr->addr_data.cname, DNS_MAX_CNAME_LEN);
+		request->has_cname = 1;
+		request->ttl_cname = cache_addr->addr_data.cname_ttl;
+	}
+
+	request->rcode = DNS_RC_NOERROR;
+
+	_dns_result_callback(request);
+
+	if (request->prefetch == 0) {
+		_dns_reply(request);
+	}
+
+	return 0;
+errout:
+	return -1;
+}
+
+static int _dns_server_process_cache_packet(struct dns_request *request, struct dns_cache *dns_cache)
+{
+	struct dns_cache_packet *cache_packet = (struct dns_cache_packet *)dns_cache_get_data(dns_cache);
+
+	if (cache_packet->head.cache_type != CACHE_TYPE_PACKET) {
+		goto errout;
+	}
+
+	if (dns_cache->info.qtype != request->qtype) {
+		goto errout;
+	}
+
+	if (atomic_inc_return(&request->notified) != 1) {
+		return 0;
+	}
+
+	if (request->result_callback) {
+		unsigned char packet_buff[DNS_PACKSIZE];
+		struct dns_packet *packet = (struct dns_packet *)packet_buff;
+
+		if (dns_decode(packet, DNS_PACKSIZE, cache_packet->data, cache_packet->head.size) != 0) {
+			goto errout;
+		}
+
+		_dns_server_get_answer(request, packet);
+		_dns_result_callback(request);
+	}
+
+	if (request->conn == NULL) {
+		return 0;
+	}
+
+	/* When passthrough, modify the id to be the id of the client request. */
+	dns_server_update_reply_packet_id(request, cache_packet->data, cache_packet->head.size);
+	return _dns_reply_inpacket(request, cache_packet->data, cache_packet->head.size);
+errout:
+	return -1;
+}
+
+static int _dns_server_process_cache_data(struct dns_request *request, struct dns_cache *dns_cache)
+{
+	enum CACHE_TYPE cache_type = CACHE_TYPE_NONE;
+	int ret = -1;
+
+	cache_type = dns_cache_data_type(dns_cache->cache_data);
+	switch (cache_type) {
+	case CACHE_TYPE_ADDR:
+		ret = _dns_server_process_cache_addr(request, dns_cache);
+		if (ret != 0) {
+			goto out;
+		}
+		break;
+	case CACHE_TYPE_PACKET:
+		ret = _dns_server_process_cache_packet(request, dns_cache);
+		if (ret != 0) {
+			goto out;
+		}
+
+		break;
+	default:
+		goto out;
+		break;
+	}
+
+	return 0;
+out:
+	return -1;
+}
+
 static int _dns_server_process_cache(struct dns_request *request)
 {
 	struct dns_cache *dns_cache = NULL;
@@ -2043,24 +2403,28 @@ static int _dns_server_process_cache(struct dns_request *request)
 			if (dns_cache_A) {
 				tlog(TLOG_DEBUG, "No IPV6 Found, Force IPV4 perfered.");
 				if (dns_cache_get_ttl(dns_cache_A) == 0) {
-					_dns_server_prefetch_request(request->domain, request->qtype);
+					uint32_t server_flags = request->server_flags;
+					if (request->conn == NULL) {
+						server_flags = dns_cache_get_cache_flag(dns_cache_A->cache_data);
+					}
+					_dns_server_prefetch_request(request->domain, request->qtype, server_flags);
 				}
-				ret =  _dns_server_reply_SOA(DNS_RC_NOERROR, request);
+				ret = _dns_server_reply_SOA(DNS_RC_NOERROR, request);
 				goto out;
 			}
 		}
 		goto out;
 	}

-	if (request->qtype != dns_cache->qtype) {
+	if (request->qtype != dns_cache->info.qtype) {
 		goto out;
 	}

 	if (request->dualstack_selection && request->qtype == DNS_T_AAAA) {
 		dns_cache_A = dns_cache_lookup(request->domain, DNS_T_A);
-		if (dns_cache_A && (dns_cache_A->speed > 0)) {
-			if ((dns_cache_A->speed + (dns_conf_dualstack_ip_selection_threshold * 10)) < dns_cache->speed ||
-				dns_cache->speed < 0) {
+		if (dns_cache_A && (dns_cache_A->info.speed > 0)) {
+			if ((dns_cache_A->info.speed + (dns_conf_dualstack_ip_selection_threshold * 10)) < dns_cache->info.speed ||
+				dns_cache->info.speed < 0) {
 				tlog(TLOG_DEBUG, "Force IPV4 perfered.");
 				ret = _dns_server_reply_SOA(DNS_RC_NOERROR, request);
 				goto out_update_cache;
@@ -2068,42 +2432,18 @@ static int _dns_server_process_cache(struct dns_request *request)
 		}
 	}

-	/* Cache hits, returning results in the cache */
-	switch (request->qtype) {
-	case DNS_T_A:
-		memcpy(request->ipv4_addr, dns_cache->ipv4_addr, DNS_RR_A_LEN);
-		request->ttl_v4 = dns_cache_get_ttl(dns_cache);
-		request->has_ipv4 = 1;
-		break;
-	case DNS_T_AAAA:
-		memcpy(request->ipv6_addr, dns_cache->ipv6_addr, DNS_RR_AAAA_LEN);
-		request->ttl_v6 = dns_cache_get_ttl(dns_cache);
-		request->has_ipv6 = 1;
-		break;
-	default:
+	ret = _dns_server_process_cache_data(request, dns_cache);
+	if (ret != 0) {
 		goto out;
-		break;
 	}

-	if (dns_cache->cname[0] != 0) {
-		safe_strncpy(request->cname, dns_cache->cname, DNS_MAX_CNAME_LEN);
-		request->has_cname = 1;
-		request->ttl_cname = dns_cache->cname_ttl;
-	}
-
-	request->rcode = DNS_RC_NOERROR;
-
-	_dns_result_callback(request);
-
-	if (request->prefetch == 0) {
-		_dns_reply(request);
-	}
-
-	ret = 0;
-
 out_update_cache:
 	if (dns_cache_get_ttl(dns_cache) == 0) {
-		_dns_server_prefetch_request(request->domain, request->qtype);
+		uint32_t server_flags = request->server_flags;
+		if (request->conn == NULL) {
+			server_flags = dns_cache_get_cache_flag(dns_cache->cache_data);
+		}
+		_dns_server_prefetch_request(request->domain, request->qtype, server_flags);
 	} else {
 		dns_cache_update(dns_cache);
 	}
@@ -2124,6 +2464,7 @@ out:
 static void _dns_server_request_set_client(struct dns_request *request, struct dns_server_conn_head *conn)
 {
 	request->conn = conn;
+	request->server_flags = conn->server_flags;
 	_dns_server_conn_get(conn);
 }

@@ -2224,6 +2565,10 @@ static void _dns_server_check_set_passthrough(struct dns_request *request)
 	if (_dns_server_has_bind_flag(request, BIND_FLAG_NO_SPEED_CHECK) == 0) {
 		request->passthrough = 1;
 	}
+
+	if (request->passthrough == 1) {
+		request->dualstack_selection = 0;
+	}
 }

 static int _dns_server_do_query(struct dns_request *request, const char *domain, int qtype)
@@ -2389,7 +2734,7 @@ errout:
 	return ret;
 }

-static int _dns_server_prefetch_request(char *domain, dns_type_t qtype)
+static int _dns_server_prefetch_request(char *domain, dns_type_t qtype, uint32_t server_flags)
 {
 	int ret = -1;
 	struct dns_request *request = NULL;
@@ -2400,6 +2745,7 @@ static int _dns_server_prefetch_request(char *domain, dns_type_t qtype)
 		goto errout;
 	}

+	request->server_flags = server_flags;
 	_dns_server_request_set_enable_prefetch(request);
 	ret = _dns_server_do_query(request, domain, qtype);
 	if (ret != 0) {
@@ -2417,7 +2763,7 @@ errout:
 	return ret;
 }

-int dns_server_query(char *domain, int qtype, dns_result_callback callback, void *user_ptr)
+int dns_server_query(char *domain, int qtype, uint32_t server_flags, dns_result_callback callback, void *user_ptr)
 {
 	int ret = -1;
 	struct dns_request *request = NULL;
@@ -2428,6 +2774,7 @@ int dns_server_query(char *domain, int qtype, dns_result_callback callback, void
 		goto errout;
 	}

+	request->server_flags = server_flags;
 	_dns_server_request_set_callback(request, callback, user_ptr);
 	ret = _dns_server_do_query(request, domain, qtype);
 	if (ret != 0) {
@@ -2439,6 +2786,7 @@ int dns_server_query(char *domain, int qtype, dns_result_callback callback, void
 	return ret;
 errout:
 	if (request) {
+		_dns_server_request_set_callback(request, NULL, NULL);
 		_dns_server_request_release(request);
 	}

@@ -2821,10 +3169,11 @@ static void _dns_server_prefetch_domain(struct dns_cache *dns_cache)
 	}

 	/* start prefetch domain */
-	tlog(TLOG_DEBUG, "prefetch by cache %s, qtype %d, ttl %d, hitnum %d", dns_cache->domain, dns_cache->qtype,
-		 dns_cache->ttl, hitnum);
-	if (_dns_server_prefetch_request(dns_cache->domain, dns_cache->qtype) != 0) {
-		tlog(TLOG_ERROR, "prefetch domain %s, qtype %d, failed.", dns_cache->domain, dns_cache->qtype);
+	tlog(TLOG_DEBUG, "prefetch by cache %s, qtype %d, ttl %d, hitnum %d", dns_cache->info.domain, dns_cache->info.qtype,
+		 dns_cache->info.ttl, hitnum);
+	if (_dns_server_prefetch_request(dns_cache->info.domain, dns_cache->info.qtype,
+									 dns_cache_get_cache_flag(dns_cache->cache_data)) != 0) {
+		tlog(TLOG_ERROR, "prefetch domain %s, qtype %d, failed.", dns_cache->info.domain, dns_cache->info.qtype);
 	}
 }

@@ -3073,7 +3422,7 @@ static int _dns_create_socket(const char *host_ip, int type)
 	setsockopt(fd, IPPROTO_IP, IP_TOS, &ip_tos, sizeof(ip_tos));

 	if (bind(fd, gai->ai_addr, gai->ai_addrlen) != 0) {
-		tlog(TLOG_ERROR, "bind service failed, %s\n", strerror(errno));
+		tlog(TLOG_ERROR, "bind service %s failed, %s\n", host_ip, strerror(errno));
 		goto errout;
 	}

@@ -3230,6 +3579,60 @@ static int _dns_server_audit_init(void)
 	return 0;
 }

+static int _dns_server_cache_init(void)
+{
+	if (dns_cache_init(dns_conf_cachesize, dns_conf_serve_expired, dns_conf_serve_expired_ttl) != 0) {
+		tlog(TLOG_ERROR, "init cache failed.");
+		return -1;
+	}
+
+	char *dns_cache_file = SMARTDNS_CACHE_FILE;
+	if (dns_conf_cache_file[0] != 0) {
+		dns_cache_file = dns_conf_cache_file;
+	}
+
+	if (dns_conf_cache_persist == 2) {
+		uint64_t freespace = get_free_space(dns_cache_file);
+		if (freespace >= CACHE_AUTO_ENABLE_SIZE) {
+			tlog(TLOG_INFO, "auto enable cache persist.");
+			dns_conf_cache_persist = 1;
+		}
+	}
+
+	if (dns_conf_cachesize <= 0 || dns_conf_cache_persist == 0) {
+		return 0;
+	}
+
+	if (dns_cache_load(dns_cache_file) != 0) {
+		tlog(TLOG_WARN, "Load cache failed.");
+		return 0;
+	}
+
+	return 0;
+}
+
+static int _dns_server_cache_save(void)
+{
+	char *dns_cache_file = SMARTDNS_CACHE_FILE;
+	if (dns_conf_cache_file[0] != 0) {
+		dns_cache_file = dns_conf_cache_file;
+	}
+
+	if (dns_conf_cache_persist == 0 || dns_conf_cachesize <= 0) {
+		if (access(dns_cache_file, F_OK) == 0) {
+			unlink(dns_cache_file);
+		}
+		return 0;
+	}
+
+	if (dns_cache_save(dns_cache_file) != 0) {
+		tlog(TLOG_WARN, "save cache failed.");
+		return -1;
+	}
+
+	return 0;
+}
+
 int dns_server_init(void)
 {
 	pthread_attr_t attr;
@@ -3240,9 +3643,9 @@ int dns_server_init(void)
 		return -1;
 	}

-	if (dns_cache_init(dns_conf_cachesize, dns_conf_serve_expired, dns_conf_serve_expired_ttl) != 0) {
-		tlog(TLOG_ERROR, "init cache failed.");
-		return -1;
+	if (_dns_server_cache_init() != 0) {
+		tlog(TLOG_ERROR, "init dns cache filed.");
+		goto errout;
 	}

 	if (_dns_server_audit_init() != 0) {
@@ -3318,5 +3721,6 @@ void dns_server_exit(void)

 	pthread_mutex_destroy(&server.request_list_lock);

+	_dns_server_cache_save();
 	dns_cache_destroy();
 }
--- a/src/dns_server.h
+++ b/src/dns_server.h
@@ -20,6 +20,7 @@
 #define _SMART_DNS_SERVER_H

 #include "dns.h"
+#include <stdint.h>

 #ifdef __cpluscplus
 extern "C" {
@@ -40,7 +41,7 @@ typedef int (*dns_result_callback)(char *domain, dns_rtcode_t rtcode, dns_type_t
 								   unsigned int ping_time, void *user_ptr);

 /* query domain */
-int dns_server_query(char *domain, int qtype, dns_result_callback callback, void *user_ptr);
+int dns_server_query(char *domain, int qtype, uint32_t server_flags, dns_result_callback callback, void *user_ptr);

 #ifdef __cpluscplus
 }
--- a/src/smartdns.c
+++ b/src/smartdns.c
@@ -439,6 +439,7 @@ int main(int argc, char *argv[])
 		goto errout;
 	}

+	signal(SIGPIPE, SIG_IGN);
 	if (dns_server_load_conf(config_file) != 0) {
 		fprintf(stderr, "load config failed.\n");
 		goto errout;
@@ -451,7 +452,7 @@ int main(int argc, char *argv[])
 	}

 	signal(SIGINT, _sig_exit);
-	signal(SIGPIPE, SIG_IGN);
+	signal(SIGTERM, _sig_exit);
 	atexit(_smartdns_exit);

 	return _smartdns_run();
--- a/src/tlog.c
+++ b/src/tlog.c
@@ -1,6 +1,6 @@
 /*
 * tinylog
- * Copyright (C) 2018-2019 Nick Peng <pymumu@gmail.com>
+ * Copyright (C) 2018-2020 Nick Peng <pymumu@gmail.com>
 * https://github.com/pymumu/tinylog
 */
 #ifndef _GNU_SOURCE
@@ -1377,7 +1377,7 @@ static void *_tlog_work(void *arg)
            log = _tlog_wait_log_locked(log);
            if (log == NULL) {
                pthread_mutex_unlock(&tlog.lock);
-                if (errno != ETIMEDOUT) {
+                if (errno != ETIMEDOUT && tlog.run) {
                    sleep(1);
                }
                continue;
--- a/src/tlog.h
+++ b/src/tlog.h
@@ -1,6 +1,6 @@
 /*
 * tinylog
- * Copyright (C) 2018-2019 Ruilin Peng (Nick) <pymumu@gmail.com>
+ * Copyright (C) 2018-2020 Ruilin Peng (Nick) <pymumu@gmail.com>
 * https://github.com/pymumu/tinylog
 */

@@ -196,6 +196,7 @@ public:
    Buffer LogStream(tlog_level level, const char *file, int line, const char *func, void *userptr) {
        return Buffer(new Stream, [=](Stream *st) {
            tlog_ext(level, file, line, func, userptr, "%s", st->str().c_str());
+            delete st;
        });
    }
 };
@@ -215,6 +216,7 @@ public:
    Buffer Out(tlog_log *log) {
        return Buffer(new Stream, [=](Stream *st) {
            tlog_printf(log, "%s", st->str().c_str());
+            delete st;
        });
    }
 };
--- a/src/util.c
+++ b/src/util.c
@@ -35,6 +35,7 @@
 #include <string.h>
 #include <sys/prctl.h>
 #include <sys/stat.h>
+#include <sys/statvfs.h>
 #include <sys/types.h>
 #include <time.h>
 #include <unistd.h>
@@ -994,4 +995,17 @@ int set_sock_lingertime(int fd, int time)
 	}

 	return 0;
-}
+}
+
+uint64_t get_free_space(const char *path)
+{
+	uint64_t size = 0;
+	struct statvfs buf;
+	if (statvfs(path, &buf) != 0) {
+		return 0;
+	}
+
+	size = (uint64_t)buf.f_frsize * buf.f_bavail;
+
+	return size;
+}
--- a/src/util.h
+++ b/src/util.h
@@ -106,6 +106,8 @@ int set_sock_keepalive(int fd, int keepidle, int keepinterval, int keepcnt);

 int set_sock_lingertime(int fd, int time);

+uint64_t get_free_space(const char *path);
+
 #ifdef __cplusplus
 }
 #endif /*__cplusplus */
--- a/systemd/smartdns.service.in
+++ b/systemd/smartdns.service.in
@@ -1,8 +1,9 @@
 [Unit]
-Description=smart dns server
+Description=smartdns server
 After=network.target 
 StartLimitBurst=0
 StartLimitIntervalSec=60
+TimeoutStopSec=5

 [Service]
 Type=forking
Author	SHA1	Message	Date
Nick Peng	86902d2e34	serve-expired: support config reply ttl	2020-09-06 15:21:37 +08:00
Nick Peng	6f30fe6d05	compile: remove O_CLOEXEC flags	2020-09-05 19:37:50 +08:00
Nick Peng	0b45da29c7	cache: support persist cache when restart smartdns	2020-09-05 12:55:30 +08:00
Nick Peng	2b81fffb7e	dns_client: fix ssl race condition issue.	2020-09-02 22:03:24 +08:00
Nick Peng	7af6f475da	dns-client: reduce ssl session cache size	2020-08-27 23:34:22 +08:00
Purple Grape	c3b6560b46	add rpm support	2020-08-25 22:02:45 +08:00
Nick Peng	a3d3364a32	dns_client: avoid disconnect with server after query complete	2020-08-24 23:54:06 +08:00
Nick Peng	b8a36ccb8c	dns_client: avoid connect failure	2020-08-24 23:18:35 +08:00
Nick Peng	aee19be262	dns-cache: support cache when speed check is disabled	2020-08-23 20:12:50 +08:00
Nick Peng	98429e88f1	speed_check: fix query failure when speed-check is none and dualstack-selection is enable.	2020-08-23 15:28:56 +08:00
Nick Peng	80cb27c795	tlog: update tlog	2020-08-22 08:13:55 +08:00
Kevin Zhou	cb73eadf01	Make the ipset working as expected when the domain passthrough	2020-08-22 07:57:00 +08:00
Nick Peng	69ba3f8789	pending: fix pending server resolve issue	2020-08-16 17:05:51 +08:00
Nick Peng	c380bbe0e3	tlog: update tlog	2020-08-13 01:23:40 +08:00
Nick Peng	da74e877c5	dns_client: repeat same arguments with SSL_write	2020-08-13 00:56:51 +08:00
Nick Peng	a300873b3f	dns-client: fix ssl send request issue	2020-08-11 00:09:38 +08:00