serve-expired: support config reply ttl

Dockerfile

@@ -0,0 +1,18 @@
+ FROM debian:buster-slim
+
+ RUN apt update && \
+     apt install -y git make gcc libssl-dev && \
+     git clone https://github.com/pymumu/smartdns.git --depth 1 && \
+     cd smartdns && \
+     sh ./package/build-pkg.sh --platform debian --arch `dpkg --print-architecture` && \
+     dpkg -i package/*.deb && \
+     cd / && \
+     rm -rf smartdns/ && \
+     apt autoremove -y git make gcc libssl-dev && \
+     apt clean && \
+     rm -rf /var/lib/apt/lists/*
+
+ EXPOSE 53/udp
+ VOLUME "/etc/smartdns/"
+
+ CMD ["/usr/sbin/smartdns", "-f"]

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

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

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]
 

package/openwrt/files/etc/init.d/smartdns

@@ -156,7 +156,7 @@ load_server()
 	config_get type "$section" "type" "udp"
 	config_get ip "$section" "ip" ""
 	config_get tls_host_verify "$section" "tls_host_verify" ""
-	config_get no_check_certificate "$section" "no_check_certificate" ""
+	config_get no_check_certificate "$section" "no_check_certificate" "0"
 	config_get host_name "$section" "host_name" ""
 	config_get http_host "$section" "http_host" ""
 	config_get server_group "$section" "server_group" ""
@@ -187,7 +187,7 @@ load_server()
 	fi
 
 	[ -z "$tls_host_verify" ] || ADDITIONAL_ARGS="$ADDITIONAL_ARGS -tls-host-verify $tls_host_verify"
-	[ -z "$no_check_certificate" ] || ADDITIONAL_ARGS="$ADDITIONAL_ARGS -no-check-certificate"
+	[ "$no_check_certificate" = "0" ] || ADDITIONAL_ARGS="$ADDITIONAL_ARGS -no-check-certificate"
 	[ -z "$host_name" ] || ADDITIONAL_ARGS="$ADDITIONAL_ARGS -host-name $host_name"
 	[ -z "$http_host" ] || ADDITIONAL_ARGS="$ADDITIONAL_ARGS -http-host $http_host"
 	[ -z "$server_group" ] || ADDITIONAL_ARGS="$ADDITIONAL_ARGS -group $server_group"

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
 	;;

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

src/dns.h

@@ -110,7 +110,7 @@ struct dns_head {
 	unsigned short ancount; /* number of answer entries */
 	unsigned short nscount; /* number of authority entries */
 	unsigned short nrcount; /* number of addititional resource entries */
-} __attribute__((packed));
+} __attribute__((packed, aligned(2)));
 
 struct dns_rrs {
 	unsigned short next;

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 0;
+		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;

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

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 */
@@ -853,15 +919,20 @@ static int _dns_client_server_add(char *server_ip, char *server_host, int port,
 #else
 		server_info->ssl_ctx = SSL_CTX_new(SSLv23_client_method());
 #endif
-		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;
-		}
 
 		if (server_info->ssl_ctx == NULL) {
 			tlog(TLOG_ERROR, "init ssl failed.");
 			goto errout;
 		}
+
+		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;
+			SSL_CTX_set_verify(server_info->ssl_ctx, SSL_VERIFY_NONE, NULL);
+		}
 	}
 
 	/* safe address info */
@@ -901,14 +972,16 @@ static int _dns_client_server_add(char *server_ip, char *server_host, int port,
 	return 0;
 errout:
 	if (server_info) {
-		if (server_info->ssl_ctx) {
-			SSL_CTX_free(server_info->ssl_ctx);
-			server_info->ssl_ctx = NULL;
-		}
 		if (server_info->ping_host) {
 			fast_ping_stop(server_info->ping_host);
 		}
 
+		if (server_info->ssl_ctx) {
+			SSL_CTX_free(server_info->ssl_ctx);
+			server_info->ssl_ctx = NULL;
+		}
+
+		pthread_mutex_destroy(&server_info->lock);
 		free(server_info);
 	}
 
@@ -927,8 +1000,12 @@ static void _dns_client_close_socket(struct dns_server_info *server_info)
 
 	if (server_info->ssl) {
 		/* Shutdown 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 */
@@ -943,6 +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 */
@@ -974,6 +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);
@@ -1427,7 +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)
@@ -1507,31 +1615,41 @@ static int _DNS_client_create_socket_tcp(struct dns_server_info *server_info)
 	set_sock_keepalive(fd, 15, 3, 4);
 
 	if (connect(fd, (struct sockaddr *)&server_info->addr, server_info->ai_addrlen) != 0) {
-		if (errno != EINPROGRESS) {
-			tlog(TLOG_ERROR, "connect failed.");
+		if (errno == ENETUNREACH) {
+			tlog(TLOG_DEBUG, "connect %s failed, %s", server_info->ip, strerror(errno));
 			goto errout;
 		}
-	}
 
-	memset(&event, 0, sizeof(event));
-	event.events = EPOLLIN | EPOLLOUT;
-	event.data.ptr = server_info;
-	if (epoll_ctl(client.epoll_fd, EPOLL_CTL_ADD, fd, &event) != 0) {
-		tlog(TLOG_ERROR, "epoll ctl failed.");
-		return -1;
+		if (errno != EINPROGRESS) {
+			tlog(TLOG_ERROR, "connect %s failed, %s", server_info->ip, strerror(errno));
+			goto errout;
+		}
 	}
 
 	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;
+	if (epoll_ctl(client.epoll_fd, EPOLL_CTL_ADD, fd, &event) != 0) {
+		tlog(TLOG_ERROR, "epoll ctl failed, %s", strerror(errno));
+		return -1;
+	}
+
 	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;
 }
 
@@ -1571,20 +1689,26 @@ static int _DNS_client_create_socket_tls(struct dns_server_info *server_info, ch
 	}
 
 	// ? this cause ssl crash ?
-	// setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &yes, sizeof(yes));
-	// setsockopt(fd, IPPROTO_TCP, TCP_THIN_DUPACK, &yes, sizeof(yes));
-	// setsockopt(fd, IPPROTO_TCP, TCP_THIN_LINEAR_TIMEOUTS, &yes, sizeof(yes));
-	// set_sock_keepalive(fd, 15, 3, 4);
+	setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &yes, sizeof(yes));
+	setsockopt(fd, IPPROTO_TCP, TCP_THIN_DUPACK, &yes, sizeof(yes));
+	setsockopt(fd, IPPROTO_TCP, TCP_THIN_LINEAR_TIMEOUTS, &yes, sizeof(yes));
+	set_sock_keepalive(fd, 15, 3, 4);
 	setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &priority, sizeof(priority));
 	setsockopt(fd, IPPROTO_IP, IP_TOS, &ip_tos, sizeof(ip_tos));
 
 	if (connect(fd, (struct sockaddr *)&server_info->addr, server_info->ai_addrlen) != 0) {
+		if (errno == ENETUNREACH) {
+			tlog(TLOG_DEBUG, "connect %s failed, %s", server_info->ip, strerror(errno));
+			goto errout;
+		}
+
 		if (errno != EINPROGRESS) {
 			tlog(TLOG_ERROR, "connect %s failed, %s", server_info->ip, strerror(errno));
 			goto errout;
 		}
 	}
 
+	SSL_set_connect_state(ssl);
 	if (SSL_set_fd(ssl, fd) == 0) {
 		tlog(TLOG_ERROR, "ssl set fd failed.");
 		goto errout;
@@ -1595,11 +1719,16 @@ static int _DNS_client_create_socket_tls(struct dns_server_info *server_info, ch
 		SSL_set_session(ssl, server_info->ssl_session);
 	}
 
-	SSL_set_mode(ssl, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
+	SSL_set_mode(ssl, SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER | SSL_MODE_ENABLE_PARTIAL_WRITE);
 	if (hostname[0] != 0) {
 		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;
@@ -1608,14 +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);
 	}
@@ -1714,30 +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);
-	if (ret >= 0) {
+	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:
-		errno = EAGAIN;
-		return -1;
-		break;
-	case SSL_ERROR_ZERO_RETURN:
 		return 0;
 		break;
+	case SSL_ERROR_ZERO_RETURN:
 	case SSL_ERROR_WANT_READ:
 		errno = EAGAIN;
 		ret = -1;
@@ -1748,12 +1881,15 @@ static int _dns_client_socket_ssl_send(SSL *ssl, const void *buf, int num)
 		break;
 	case SSL_ERROR_SSL:
 		ssl_err = ERR_get_error();
-		if (ERR_GET_REASON(ssl_err) == SSL_R_UNINITIALIZED || ERR_GET_REASON(ssl_err) == SSL_R_PROTOCOL_IS_SHUTDOWN) {
+		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_WRITE_RETRY) {
 			errno = EAGAIN;
 			return -1;
 		}
 
-		tlog(TLOG_DEBUG, "SSL write fail error no:  %s(%ld)\n", ERR_reason_error_string(ssl_err), ssl_err);
+		tlog(TLOG_ERROR, "SSL write fail error no:  %s(%d)\n", ERR_reason_error_string(ssl_err), ssl_reason);
 		errno = EFAULT;
 		ret = -1;
 		break;
@@ -1769,28 +1905,25 @@ 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:
-		errno = EAGAIN;
-		return -1;
-		break;
 	case SSL_ERROR_ZERO_RETURN:
 		return 0;
 		break;
@@ -1804,16 +1937,25 @@ static int _dns_client_socket_ssl_recv(SSL *ssl, void *buf, int num)
 		break;
 	case SSL_ERROR_SSL:
 		ssl_err = ERR_get_error();
-		if (ERR_GET_REASON(ssl_err) == SSL_R_UNINITIALIZED) {
+		int ssl_reason = ERR_GET_REASON(ssl_err);
+		if (ssl_reason == SSL_R_UNINITIALIZED) {
 			errno = EAGAIN;
 			return -1;
 		}
 
-		tlog(TLOG_ERROR, "SSL read fail error no: %s(%ld)\n", ERR_reason_error_string(ssl_err), ssl_err);
+		if (ssl_reason == SSL_R_SHUTDOWN_WHILE_IN_INIT || ssl_reason == SSL_R_PROTOCOL_IS_SHUTDOWN) {
+			return 0;
+		}
+
+		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));
 		}
@@ -1835,7 +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;
 	}
@@ -1849,7 +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;
@@ -1967,6 +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;
 		}
@@ -2096,11 +2254,31 @@ 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)
+{
+	X509_NAME *cert_name = NULL;
+
+	cert_name = X509_get_subject_name(cert);
+	if (cert_name == NULL) {
+		tlog(TLOG_ERROR, "get subject name failed.");
+		goto errout;
+	}
+
+	if (X509_NAME_get_text_by_NID(cert_name, NID_commonName, cn, max_cn_len) == -1) {
+		tlog(TLOG_ERROR, "cannot found x509 name");
+		goto errout;
+	}
+
+	return 0;
+
+errout:
+	return -1;
+}
+
 static int _dns_client_tls_verify(struct dns_server_info *server_info)
 {
 	X509 *cert = NULL;
 	X509_PUBKEY *pubkey = NULL;
-	X509_NAME *cert_name = NULL;
 	char peer_CN[256];
 	char cert_fingerprint[256];
 	int i = 0;
@@ -2115,8 +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;
 	}
@@ -2124,24 +2304,22 @@ 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) {
-			tlog(TLOG_WARN, "peer server certificate verify failed.");
+			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);
+			tlog(TLOG_WARN, "peer CN: %s", peer_CN);
 			goto errout;
 		}
 	}
+	pthread_mutex_unlock(&server_info->lock);
 
-	cert_name = X509_get_subject_name(cert);
-	if (cert_name == NULL) {
-		tlog(TLOG_ERROR, "get subject name failed.");
-		goto errout;
-	}
-
-	if (X509_NAME_get_text_by_NID(cert_name, NID_commonName, peer_CN, 256) == -1) {
-		tlog(TLOG_ERROR, "cannot found x509 name");
+	if (_dns_client_tls_get_cert_CN(cert, peer_CN, sizeof(peer_CN)) != 0) {
+		tlog(TLOG_ERROR, "get cert CN failed.");
 		goto errout;
 	}
 
 	tlog(TLOG_DEBUG, "peer CN: %s", peer_CN);
-
 	/* check tls host */
 	tls_host_verify = _dns_client_server_get_tls_host_verify(server_info);
 	if (tls_host_verify) {
@@ -2234,17 +2412,26 @@ 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_connect(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) {
-				fd_event.events = EPOLLOUT;
+				fd_event.events = EPOLLOUT | EPOLLIN;
+			} else if (ssl_ret == SSL_ERROR_SYSCALL) {
+				if (errno != ENETUNREACH) {
+					tlog(TLOG_WARN, "Handshake with %s failed, %s", server_info->ip, strerror(errno));
+				}
+				goto errout;
 			} else {
+				unsigned long ssl_err = ERR_get_error();
+				int ssl_reason = ERR_GET_REASON(ssl_err);
+				tlog(TLOG_WARN, "Handshake with %s failed, error no: %s(%d, %d, %d)\n", server_info->ip,
+					 ERR_reason_error_string(ssl_err), ret, ssl_ret, ssl_reason);
 				goto errout;
 			}
 
@@ -2259,7 +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");
@@ -2277,7 +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);
 		}
 
@@ -2351,7 +2538,7 @@ static int _dns_client_send_data_to_buffer(struct dns_server_info *server_info,
 	event.events = EPOLLIN | EPOLLOUT;
 	event.data.ptr = server_info;
 	if (epoll_ctl(client.epoll_fd, EPOLL_CTL_MOD, server_info->fd, &event) != 0) {
-		tlog(TLOG_ERROR, "epoll ctl failed.");
+		tlog(TLOG_ERROR, "epoll ctl failed, %s", strerror(errno));
 		return -1;
 	}
 
@@ -2424,16 +2611,17 @@ static int _dns_client_send_tls(struct dns_server_info *server_info, void *packe
 	}
 
 	if (server_info->ssl == NULL) {
+		errno = EINVAL;
 		return -1;
 	}
 
-	send_len = _dns_client_socket_ssl_send(server_info->ssl, inpacket, len);
-	if (send_len < 0) {
+	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) {
@@ -2474,16 +2662,17 @@ static int _dns_client_send_https(struct dns_server_info *server_info, void *pac
 	}
 
 	if (server_info->ssl == NULL) {
+		errno = EINVAL;
 		return -1;
 	}
 
-	send_len = _dns_client_socket_ssl_send(server_info->ssl, inpacket, http_len);
-	if (send_len < 0) {
+	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) {
@@ -2501,63 +2690,85 @@ static int _dns_client_send_packet(struct dns_query_struct *query, void *packet,
 	struct dns_server_group_member *tmp = NULL;
 	int ret = 0;
 	int send_err = 0;
+	int i = 0;
 
 	query->send_tick = get_tick_count();
 
 	/* send query to all dns servers */
-	pthread_mutex_lock(&client.server_list_lock);
-	list_for_each_entry_safe(group_member, tmp, &query->server_group->head, list)
-	{
-		server_info = group_member->server;
-		if (server_info->fd <= 0) {
-			ret = _dns_client_create_socket(server_info);
-			if (ret != 0) {
-				continue;
+	for (i = 0; i < 2; i++) {
+		pthread_mutex_lock(&client.server_list_lock);
+		list_for_each_entry_safe(group_member, tmp, &query->server_group->head, list)
+		{
+			server_info = group_member->server;
+			if (server_info->fd <= 0) {
+				ret = _dns_client_create_socket(server_info);
+				if (ret != 0) {
+					continue;
+				}
 			}
-		}
 
-		atomic_inc(&query->dns_request_sent);
-		switch (server_info->type) {
-		case DNS_SERVER_UDP:
-			/* udp query */
-			ret = _dns_client_send_udp(server_info, packet, len);
-			send_err = errno;
-			break;
-		case DNS_SERVER_TCP:
-			/* tcp query */
-			ret = _dns_client_send_tcp(server_info, packet, len);
-			send_err = errno;
-			break;
-		case DNS_SERVER_TLS:
-			/* tls query */
-			ret = _dns_client_send_tls(server_info, packet, len);
-			send_err = errno;
-			break;
-		case DNS_SERVER_HTTPS:
-			/* https query */
-			ret = _dns_client_send_https(server_info, packet, len);
-			send_err = errno;
-			break;
-		default:
-			/* unsupport query type */
-			ret = -1;
-			break;
-		}
+			atomic_inc(&query->dns_request_sent);
+			switch (server_info->type) {
+			case DNS_SERVER_UDP:
+				/* udp query */
+				ret = _dns_client_send_udp(server_info, packet, len);
+				send_err = errno;
+				break;
+			case DNS_SERVER_TCP:
+				/* tcp query */
+				ret = _dns_client_send_tcp(server_info, packet, len);
+				send_err = errno;
+				break;
+			case DNS_SERVER_TLS:
+				/* tls query */
+				ret = _dns_client_send_tls(server_info, packet, len);
+				send_err = errno;
+				break;
+			case DNS_SERVER_HTTPS:
+				/* https query */
+				ret = _dns_client_send_https(server_info, packet, len);
+				send_err = errno;
+				break;
+			default:
+				/* unsupport query type */
+				ret = -1;
+				break;
+			}
+
+			if (ret != 0) {
+				if (send_err == ENETUNREACH) {
+					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);
+					atomic_dec(&query->dns_request_sent);
+					continue;
+				}
 
-		if (ret != 0) {
-			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 || send_err != ENOMEM) {
+					_dns_client_shutdown_socket(server_info);
+				}
+
+				atomic_dec(&query->dns_request_sent);
+				continue;
 			}
-			atomic_dec(&query->dns_request_sent);
-			continue;
+			time(&server_info->last_send);
+		}
+		pthread_mutex_unlock(&client.server_list_lock);
+
+		if (atomic_read(&query->dns_request_sent) > 0) {
+			break;
 		}
-		time(&server_info->last_send);
 	}
-	pthread_mutex_unlock(&client.server_list_lock);
+
+	if (atomic_read(&query->dns_request_sent) <= 0) {
+		tlog(TLOG_ERROR, "Send query to upstream server failed.");
+		return -1;
+	}
+
 	return 0;
 }
 
@@ -2797,7 +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);
 			}
 		}
@@ -2805,14 +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 {

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) {
@@ -262,6 +270,7 @@ static int _config_server(int argc, char *argv[], dns_server_type_t type, int de
 		return -1;
 	}
 
+	ip = argv[1];
 	if (index >= DNS_MAX_SERVERS) {
 		tlog(TLOG_WARN, "exceeds max server number, %s", ip);
 		return 0;
@@ -274,8 +283,6 @@ static int _config_server(int argc, char *argv[], dns_server_type_t type, int de
 	server->httphost[0] = '\0';
 	server->tls_host_verify[0] = '\0';
 
-	ip = argv[1];
-
 	if (type == DNS_SERVER_HTTPS) {
 		if (parse_uri(ip, NULL, server->server, &port, server->path) != 0) {
 			return -1;
@@ -871,6 +878,7 @@ static int _config_bind_ip(int argc, char *argv[], DNS_BIND_TYPE type)
 		goto errout;
 	}
 
+	ip = argv[1];
 	if (index >= DNS_MAX_SERVERS) {
 		tlog(TLOG_WARN, "exceeds max server number, %s", ip);
 		return 0;
@@ -879,7 +887,6 @@ static int _config_bind_ip(int argc, char *argv[], DNS_BIND_TYPE type)
 	bind_ip = &dns_conf_bind_ip[index];
 	bind_ip->type = type;
 	bind_ip->flags = 0;
-	ip = argv[1];
 	safe_strncpy(bind_ip->ip, ip, DNS_MAX_IPLEN);
 
 	/* process extra options */
@@ -1355,9 +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),

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];

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)
@@ -880,6 +952,7 @@ static void _dns_server_select_possible_ipaddress(struct dns_request *request)
 
 	/* Return the most likely correct IP address */
 	/* Returns the IP with the most hits, or the last returned record is considered to be the most likely correct. */
+	pthread_mutex_lock(&request->ip_map_lock);
 	hash_for_each_safe(request->ip_map, bucket, tmp, addr_map, node)
 	{
 		if (addr_map->addr_type != request->qtype) {
@@ -896,6 +969,7 @@ static void _dns_server_select_possible_ipaddress(struct dns_request *request)
 			maxhit_addr_map = addr_map;
 		}
 	}
+	pthread_mutex_unlock(&request->ip_map_lock);
 
 	if (maxhit_addr_map && maxhit > 1) {
 		selected_addr_map = maxhit_addr_map;
@@ -966,11 +1040,13 @@ static void _dns_server_request_release_complete(struct dns_request *request, in
 		_dns_server_request_complete(request);
 	}
 
+	pthread_mutex_lock(&request->ip_map_lock);
 	hash_for_each_safe(request->ip_map, bucket, tmp, addr_map, node)
 	{
 		hash_del(&addr_map->node);
 		free(addr_map);
 	}
+	pthread_mutex_unlock(&request->ip_map_lock);
 
 	_dns_server_delete_request(request);
 }
@@ -1192,20 +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)
 {
@@ -1627,6 +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)
 {
@@ -1636,6 +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;
 	}
@@ -1644,7 +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,
@@ -1669,7 +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) {
@@ -1787,7 +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;
 	}
@@ -2009,7 +2251,7 @@ errout:
 	return -1;
 }
 
-static void _dns_server_prolcess_speed_check_rule(struct dns_request *request)
+static void _dns_server_process_speed_check_rule(struct dns_request *request)
 {
 	struct dns_domain_check_order *check_order = NULL;
 
@@ -2022,56 +2264,33 @@ static void _dns_server_prolcess_speed_check_rule(struct dns_request *request)
 	request->check_order_list = check_order;
 }
 
-static int _dns_server_process_cache(struct dns_request *request)
+static int _dns_server_get_expired_ttl_reply(struct dns_cache *dns_cache)
 {
-	struct dns_cache *dns_cache = NULL;
-	struct dns_cache *dns_cache_A = NULL;
+	int ttl = dns_cache_get_ttl(dns_cache);
+	if (ttl > 0) {
+		return ttl;
+	}
 
-	if (_dns_server_has_bind_flag(request, BIND_FLAG_NO_CACHE) == 0) {
+	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;
 	}
-
-	dns_cache = dns_cache_lookup(request->domain, request->qtype);
-	if (dns_cache == NULL) {
-		if (request->dualstack_selection && request->qtype == DNS_T_AAAA) {
-			dns_cache_A = dns_cache_lookup(request->domain, DNS_T_A);
-			if (dns_cache_A) {
-				tlog(TLOG_DEBUG, "No IPV6 Found, Force IPV4 perfered.");
-				dns_cache_release(dns_cache_A);
-				dns_cache_release(dns_cache);
-				return _dns_server_reply_SOA(DNS_RC_NOERROR, request);
-			}
-		}
-		goto errout;
-	}
-
-	if (request->qtype != dns_cache->qtype) {
-		goto errout;
-	}
-
-	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) {
-				tlog(TLOG_DEBUG, "Force IPV4 perfered.");
-				dns_cache_release(dns_cache_A);
-				dns_cache_release(dns_cache);
-				return _dns_server_reply_SOA(DNS_RC_NOERROR, 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);
+		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, dns_cache->ipv6_addr, DNS_RR_AAAA_LEN);
-		request->ttl_v6 = dns_cache_get_ttl(dns_cache);
+		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:
@@ -2079,10 +2298,10 @@ static int _dns_server_process_cache(struct dns_request *request)
 		break;
 	}
 
-	if (dns_cache->cname[0] != 0) {
-		safe_strncpy(request->cname, dns_cache->cname, DNS_MAX_CNAME_LEN);
+	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 = dns_cache->cname_ttl;
+		request->ttl_cname = cache_addr->addr_data.cname_ttl;
 	}
 
 	request->rcode = DNS_RC_NOERROR;
@@ -2093,33 +2312,159 @@ static int _dns_server_process_cache(struct dns_request *request)
 		_dns_reply(request);
 	}
 
-	if (dns_cache_get_ttl(dns_cache) == 0) {
-		_dns_server_prefetch_request(request->domain, request->qtype);
-	} else {
-		dns_cache_update(dns_cache);
-	}
-	dns_cache_release(dns_cache);
+	return 0;
+errout:
+	return -1;
+}
 
-	if (dns_cache_A) {
-		dns_cache_release(dns_cache_A);
-		dns_cache_A = NULL;
+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;
-errout:
+out:
+	return -1;
+}
+
+static int _dns_server_process_cache(struct dns_request *request)
+{
+	struct dns_cache *dns_cache = NULL;
+	struct dns_cache *dns_cache_A = NULL;
+	int ret = -1;
+
+	if (_dns_server_has_bind_flag(request, BIND_FLAG_NO_CACHE) == 0) {
+		goto out;
+	}
+
+	dns_cache = dns_cache_lookup(request->domain, request->qtype);
+	if (dns_cache == NULL) {
+		if (request->dualstack_selection && request->qtype == DNS_T_AAAA) {
+			dns_cache_A = dns_cache_lookup(request->domain, DNS_T_A);
+			if (dns_cache_A) {
+				tlog(TLOG_DEBUG, "No IPV6 Found, Force IPV4 perfered.");
+				if (dns_cache_get_ttl(dns_cache_A) == 0) {
+					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);
+				goto out;
+			}
+		}
+		goto out;
+	}
+
+	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->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;
+			}
+		}
+	}
+
+	ret = _dns_server_process_cache_data(request, dns_cache);
+	if (ret != 0) {
+		goto out;
+	}
+
+out_update_cache:
+	if (dns_cache_get_ttl(dns_cache) == 0) {
+		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);
+	}
+
+out:
 	if (dns_cache) {
 		dns_cache_release(dns_cache);
 	}
+
 	if (dns_cache_A) {
 		dns_cache_release(dns_cache_A);
 		dns_cache_A = NULL;
 	}
-	return -1;
+
+	return ret;
 }
 
 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);
 }
 
@@ -2220,6 +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)
@@ -2257,7 +2606,7 @@ static int _dns_server_do_query(struct dns_request *request, const char *domain,
 	}
 
 	/* process speed check rule */
-	_dns_server_prolcess_speed_check_rule(request);
+	_dns_server_process_speed_check_rule(request);
 
 	/* check and set passthrough */
 	_dns_server_check_set_passthrough(request);
@@ -2385,7 +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;
@@ -2396,6 +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) {
@@ -2413,7 +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;
@@ -2424,6 +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) {
@@ -2435,6 +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);
 	}
 
@@ -2817,10 +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);
 	}
 }
 
@@ -3069,7 +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;
 	}
 
@@ -3226,6 +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;
@@ -3236,9 +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) {
@@ -3314,5 +3721,6 @@ void dns_server_exit(void)
 
 	pthread_mutex_destroy(&server.request_list_lock);
 
+	_dns_server_cache_save();
 	dns_cache_destroy();
 }

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
 }

src/http_parse.c

@@ -19,6 +19,7 @@
 #include "http_parse.h"
 #include "hash.h"
 #include "hashtable.h"
+#include "util.h"
 #include "jhash.h"
 #include "list.h"
 #include <stdlib.h>
@@ -214,7 +215,7 @@ static int _http_head_parse_response(struct http_head *http_head, char *key, cha
 {
 	char *field_start = NULL;
 	char *tmp_ptr = NULL;
-	char *result = NULL;
+	char *ret_msg = NULL;
 	char *ret_code = NULL;
 
 	if (strstr(key, "HTTP/") == NULL) {
@@ -226,29 +227,27 @@ static int _http_head_parse_response(struct http_head *http_head, char *key, cha
 			field_start = tmp_ptr;
 		}
 
-		if (*tmp_ptr == ' ') {
-			*tmp_ptr = '\0';
-			if (ret_code == NULL) {
-				ret_code = field_start;
-			} else if (result == NULL) {
-				result = field_start;
-				break;
-			}
-
-			field_start = NULL;
+		if (*tmp_ptr != ' ') {
+			continue;
 		}
+		
+		*tmp_ptr = '\0';
+		ret_code = field_start;
+		ret_msg = tmp_ptr + 1;
+		field_start = NULL;
+		break;
 	}
 
-	if (field_start && result == NULL) {
-		result = field_start;
+	if (ret_code == NULL || ret_msg == NULL) {
+		return -1;
 	}
 
-	if (ret_code == NULL || result == NULL) {
+	if (is_numeric(ret_code) != 0) {
 		return -1;
 	}
 
 	http_head->code = atol(ret_code);
-	http_head->code_msg = result;
+	http_head->code_msg = ret_msg;
 	http_head->version = key;
 	http_head->head_type = HTTP_HEAD_RESPONSE;
 

src/include/atomic.h

@@ -20,12 +20,6 @@
 #ifndef _GENERIC_ATOMIC_H
 #define _GENERIC_ATOMIC_H
 
-
-/* Check GCC version, just to be safe */
-#if !defined(__GNUC__) || (__GNUC__ < 4) || (__GNUC_MINOR__ < 1)
-# error atomic.h works only with GCC newer than version 4.1
-#endif /* GNUC >= 4.1 */
-
 /**
  * Atomic type.
  */

src/smartdns.c

@@ -339,24 +339,30 @@ static void _sig_error_exit(int signo, siginfo_t *siginfo, void *ct)
 {
 	unsigned long PC = 0;
 	ucontext_t *context = ct;
+	const char *arch = NULL;
 #if defined(__i386__)
 	int *pgregs = (int *)(&(context->uc_mcontext.gregs));
 	PC = pgregs[REG_EIP];
+	arch = "i386";
 #elif defined(__x86_64__)
 	int *pgregs = (int *)(&(context->uc_mcontext.gregs));
 	PC = pgregs[REG_RIP];
+	arch = "x86_64";
 #elif defined(__arm__)
 	PC = context->uc_mcontext.arm_pc;
+	arch = "arm";
 #elif defined(__aarch64__)
 	PC = context->uc_mcontext.pc;
+	arch = "arm64";
 #elif defined(__mips__)
 	PC = context->uc_mcontext.pc;
+	arch = "mips";
 #endif
 	tlog(TLOG_FATAL,
 		 "process exit with signal %d, code = %d, errno = %d, pid = %d, self = %d, pc = %#lx, addr = %#lx, build(%s "
-		 "%s)\n",
+		 "%s %s)\n",
 		 signo, siginfo->si_code, siginfo->si_errno, siginfo->si_pid, getpid(), PC, (unsigned long)siginfo->si_addr,
-		 __DATE__, __TIME__);
+		 __DATE__, __TIME__, arch);
 
 	sleep(1);
 	_exit(0);
@@ -433,6 +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;
@@ -445,7 +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();

src/tlog.c

@@ -94,7 +94,7 @@ struct tlog {
 };
 
 struct tlog_segment_log_head {
-    struct tlog_info info;
+    struct tlog_loginfo info;
     unsigned short len;
     char data[0];
 }  __attribute__((packed));
@@ -117,7 +117,7 @@ struct count_log {
 };
 
 struct tlog_info_inter {
-    struct tlog_info info;
+    struct tlog_loginfo info;
     void *userptr;
 };
 
@@ -166,6 +166,10 @@ static int _tlog_mkdir(const char *path)
     if (access(path, F_OK) == 0) {
         return 0;
     }
+    
+    while(*path == ' ' && *path != '\0') {
+        path++;
+    }
 
     strncpy(path_c, path, sizeof(path_c) - 1);
     path_c[sizeof(path_c) - 1] = '\0';
@@ -181,6 +185,11 @@ static int _tlog_mkdir(const char *path)
             continue;
         }
 
+        if (path_end == path_c) {
+            path_end++;
+            continue;
+        }
+
         str = *path_end;
         *path_end = '\0';
         if (access(path_c, F_OK) == 0) {
@@ -203,8 +212,8 @@ static int _tlog_mkdir(const char *path)
 
 static struct tm *_tlog_localtime(time_t *timep, struct tm *tm)
 {
-    static time_t last_time = {0};
-    static struct tm last_tm = {0};
+    static time_t last_time;
+    static struct tm last_tm;
 
     /* localtime_r has a global timezone lock, it's about 8 times slower than gmtime
      * this code is used to speed up localtime_r call.
@@ -297,11 +306,14 @@ void *tlog_get_private(tlog_log *log)
     return log->private_data;
 }
 
-static int _tlog_format(char *buff, int maxlen, struct tlog_info *info, void *userptr, const char *format, va_list ap)
+static int _tlog_format(char *buff, int maxlen, struct tlog_loginfo *info, void *userptr, const char *format, va_list ap)
 {
     int len = 0;
     int total_len = 0;
     struct tlog_time *tm = &info->time;
+    void* unused __attribute__ ((unused));
+
+    unused = userptr;
 
     if (tlog.root->multi_log) {
         /* format prefix */
@@ -388,6 +400,9 @@ static int _tlog_print_buffer(char *buff, int maxlen, void *userptr, const char
 {
     int len;
     int total_len = 0;
+    void* unused __attribute__ ((unused));
+
+    unused = userptr;
 
     /* format log message */
     len = vsnprintf(buff, maxlen, format, ap);
@@ -550,8 +565,9 @@ int tlog_printf(struct tlog_log *log, const char *format, ...)
 static int _tlog_early_print(const char *format, va_list ap) 
 {
     char log_buf[TLOG_MAX_LINE_LEN];
-    int len = 0;
-    int out_len = 0;
+    size_t len = 0;
+    size_t out_len = 0;
+    int unused __attribute__ ((unused));
 
     if (tlog_disable_early_print) {
         return 0;
@@ -565,9 +581,9 @@ static int _tlog_early_print(const char *format, va_list ap)
         out_len = sizeof(log_buf);
     }
 
-    write(STDOUT_FILENO, log_buf, out_len);
+    unused = write(STDOUT_FILENO, log_buf, out_len);
     if (log_buf[out_len - 1] != '\n') {
-        write(STDOUT_FILENO, "\n", 1);
+        unused = write(STDOUT_FILENO, "\n", 1);
     }
 
     return len;
@@ -650,6 +666,7 @@ static int _tlog_list_dir(const char *path, list_callback callback, void *userpt
     DIR *dir = NULL;
     struct dirent *ent;
     int ret = 0;
+    const char* unused __attribute__ ((unused)) = path;
 
     dir = opendir(path);
     if (dir == NULL) {
@@ -682,6 +699,7 @@ static int _tlog_count_log_callback(const char *path, struct dirent *entry, void
     struct count_log *count_log = (struct count_log *)userptr;
     struct tlog_log *log = count_log->log;
     char logname[TLOG_LOG_NAME_LEN * 2];
+    const char* unused __attribute__ ((unused)) = path;
 
     if (strstr(entry->d_name, log->suffix) == NULL) {
         return 0;
@@ -1005,9 +1023,10 @@ static int _tlog_archive_log(struct tlog_log *log)
     }
 }
 
-static int _tlog_write(struct tlog_log *log, char *buff, int bufflen)
+static int _tlog_write(struct tlog_log *log, const char *buff, int bufflen)
 {
     int len;
+    int unused __attribute__ ((unused));
 
     if (bufflen <= 0) {
         return 0;
@@ -1015,7 +1034,7 @@ static int _tlog_write(struct tlog_log *log, char *buff, int bufflen)
 
      /* output log to screen */
     if (log->logscreen) {
-        write(STDOUT_FILENO, buff, bufflen);
+        unused = write(STDOUT_FILENO, buff, bufflen);
     }
 
     /* if log file size exceeds threshold, start to compress */
@@ -1027,7 +1046,7 @@ static int _tlog_write(struct tlog_log *log, char *buff, int bufflen)
         if (log->filesize < lseek(log->fd, 0, SEEK_END) && log->multi_log == 0) {
             const char *msg = "[Auto enable multi-process write mode, log may be lost, please enable multi-process write mode manually]\n";
             log->multi_log = 1;
-            write(log->fd, msg, strlen(msg));
+            unused = write(log->fd, msg, strlen(msg));
         }
         close(log->fd);
         log->fd = -1;
@@ -1083,7 +1102,7 @@ static int _tlog_write(struct tlog_log *log, char *buff, int bufflen)
     return len;
 }
 
-int tlog_write(struct tlog_log *log, char *buff, int bufflen)
+int tlog_write(struct tlog_log *log, const char *buff, int bufflen)
 {
     return _tlog_write(log, buff, bufflen);
 }
@@ -1297,7 +1316,7 @@ static void _tlog_work_write(struct tlog_log *log, int log_len, int log_extlen,
     }
 }
 
-static int _tlog_root_write_log(struct tlog_log *log, char *buff, int bufflen)
+static int _tlog_root_write_log(struct tlog_log *log, const char *buff, int bufflen)
 {
     struct tlog_segment_log_head *head = NULL;
     static struct tlog_segment_log_head empty_info;
@@ -1326,7 +1345,10 @@ static void *_tlog_work(void *arg)
     int log_dropped = 0;
     struct tlog_log *log = NULL;
     struct tlog_log *loop_log = NULL;
+    void* unused __attribute__ ((unused));
 
+    unused = arg;
+    
     while (1) {
         log_len = 0;
         log_extlen = 0;
@@ -1355,7 +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;
@@ -1491,6 +1513,11 @@ int tlog_setlevel(tlog_level level)
     return 0;
 }
 
+tlog_level tlog_getlevel(void)
+{
+    return tlog_set_level;
+}
+
 tlog_log *tlog_open(const char *logfile, int maxlogsize, int maxlogcount, int buffsize, unsigned int flag)
 {
     struct tlog_log *log = NULL;

src/tlog.h

@@ -9,6 +9,11 @@
 #include <stdarg.h>
 
 #ifdef __cplusplus
+#include <string>
+#include <memory>
+#include <sstream>
+#include <iostream>
+#include <functional>
 extern "C" {
 #endif /*__cplusplus */
 
@@ -55,7 +60,7 @@ struct tlog_time {
 /* enable log to screen */
 #define TLOG_SCREEN (1 << 4)
 
-struct tlog_info {
+struct tlog_loginfo {
     tlog_level level;
     const char *file;
     const char *func;
@@ -83,6 +88,9 @@ extern int tlog_write_log(char *buff, int bufflen);
 /* set log level */
 extern int tlog_setlevel(tlog_level level);
 
+/* get log level */
+extern tlog_level tlog_getlevel(void);
+
 /* enalbe log to screen */
 extern void tlog_setlogscreen(int enable);
 
@@ -113,13 +121,13 @@ steps:
 
 read _tlog_format for example.
 */
-typedef int (*tlog_format_func)(char *buff, int maxlen, struct tlog_info *info, void *userptr, const char *format, va_list ap);
+typedef int (*tlog_format_func)(char *buff, int maxlen, struct tlog_loginfo *info, void *userptr, const char *format, va_list ap);
 extern int tlog_reg_format_func(tlog_format_func func);
 
 /* register log output callback 
  Note: info is invalid when flag TLOG_SEGMENT is not set.
  */
-typedef int (*tlog_log_output_func)(struct tlog_info *info, char *buff, int bufflen, void *private_data);
+typedef int (*tlog_log_output_func)(struct tlog_loginfo *info, const char *buff, int bufflen, void *private_data);
 extern int tlog_reg_log_output_func(tlog_log_output_func output, void *private_data);
 
 struct tlog_log;
@@ -132,11 +140,11 @@ maxlogcount: Number of archived logs.
 buffsize: Buffer size, zero for default (128K)
 flag: read tlog flags
 return: log stream handler.
- */
+*/
 extern tlog_log *tlog_open(const char *logfile, int maxlogsize, int maxlogcount, int buffsize, unsigned int flag);
 
 /* write buff to log file */
-extern int tlog_write(struct tlog_log *log, char *buff, int bufflen);
+extern int tlog_write(struct tlog_log *log, const char *buff, int bufflen);
 
 /* close log stream */
 extern void tlog_close(tlog_log *log);
@@ -160,7 +168,7 @@ extern int tlog_vprintf(tlog_log *log, const char *format, va_list ap);
 extern void tlog_logscreen(tlog_log *log, int enable);
 
 /* register output callback */
-typedef int (*tlog_output_func)(struct tlog_log *log, char *buff, int bufflen);
+typedef int (*tlog_output_func)(struct tlog_log *log, const char *buff, int bufflen);
 extern int tlog_reg_output_func(tlog_log *log, tlog_output_func output);
 
 /* set private data */
@@ -173,6 +181,65 @@ extern void *tlog_get_private(tlog_log *log);
 extern int tlog_localtime(struct tlog_time *tm);
 
 #ifdef __cplusplus
-}
-#endif /*__cplusplus */
+class Tlog {
+    using Stream = std::ostringstream;
+    using Buffer = std::unique_ptr<Stream, std::function<void(Stream*)>>;
+public:
+    Tlog(){}
+    ~Tlog(){}
+
+    static Tlog &Instance() {
+        static Tlog logger;
+        return logger;
+    }
+
+    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;
+        });
+    }
+};
+
+class TlogOut {
+    using Stream = std::ostringstream;
+    using Buffer = std::unique_ptr<Stream, std::function<void(Stream*)>>;
+public:
+    TlogOut(){}
+    ~TlogOut(){}
+
+    static TlogOut &Instance() {
+        static TlogOut logger;
+        return logger;
+    }
+
+    Buffer Out(tlog_log *log) {
+        return Buffer(new Stream, [=](Stream *st) {
+            tlog_printf(log, "%s", st->str().c_str());
+            delete st;
+        });
+    }
+};
+
+#define Tlog_logger (Tlog::Instance())
+#define Tlog_stream(level) if (tlog_getlevel() <= level) *Tlog_logger.LogStream(level, BASE_FILE_NAME, __LINE__, __func__, NULL) 
+#define tlog_debug Tlog_stream(TLOG_DEBUG)
+#define tlog_info Tlog_stream(TLOG_INFO)
+#define tlog_notice Tlog_stream(TLOG_NOTICE)
+#define tlog_warn Tlog_stream(TLOG_WARN)
+#define tlog_error Tlog_stream(TLOG_ERROR)
+#define tlog_fatal Tlog_stream(TLOG_FATAL)
+
+#define Tlog_out_logger (TlogOut::Instance())
+#define tlog_out(stream)  (*Tlog_out_logger.Out(stream))
+
+} /*__cplusplus */
+#else
+#define tlog_debug(...) tlog(TLOG_DEBUG, ##__VA_ARGS__)
+#define tlog_info(...) tlog(TLOG_INFO, ##__VA_ARGS__)
+#define tlog_notice(...) tlog(TLOG_NOTICE, ##__VA_ARGS__)
+#define tlog_warn(...) tlog(TLOG_WARN, ##__VA_ARGS__)
+#define tlog_error(...) tlog(TLOG_ERROR, ##__VA_ARGS__)
+#define tlog_fatal(...) tlog(TLOG_FATAL, ##__VA_ARGS__)
+#endif 
 #endif // !TLOG_H

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>
@@ -947,6 +948,16 @@ void get_compiled_time(struct tm *tm)
 	tm->tm_sec = sec;
 }
 
+int is_numeric(const char *str)
+{
+	while (*str != '\0') {
+		if (*str < '0' || *str > '9')
+			return -1;
+		str++;
+	}
+	return 0;
+}
+
 int has_network_raw_cap(void)
 {
 	int fd = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
@@ -984,4 +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;
+}

src/util.h

@@ -98,12 +98,16 @@ int parse_tls_header(const char *data, size_t data_len, char *hostname, const ch
 
 void get_compiled_time(struct tm *tm);
 
+int is_numeric(const char *str);
+
 int has_network_raw_cap(void);
 
 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 */

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