Update readme

smartdns: support no create pid file.
fast_ping: supress error log
2022-08-06 16:24:33 +08:00 · 2022-08-05 22:13:26 +08:00 · 2022-08-04 21:40:18 +08:00 · 2022-08-01 21:58:51 +08:00 · 2022-07-31 15:49:10 +08:00 · 2022-07-25 22:54:27 +08:00
29 changed files with 1516 additions and 761 deletions
--- a/.github/ISSUE_TEMPLATE/issue.md
+++ b/.github/ISSUE_TEMPLATE/issue.md
@@ -15,6 +15,11 @@ assignees: ''

 2. 运营商  

+3. smartdns来源以及版本
+
+4. 涉及的配置(注意去除个人相关信息)
+
+
 **重现步骤**
 1. 上游DNS配置。  

@@ -22,8 +27,8 @@ assignees: ''


 **信息收集**  
-1. 将/var/log/smrtdns.log日志作为附件上传。  
-2. 如进程异常，请将coredump功能开启，上传coredump信息文件。  
+1. 将/var/log/smrtdns.log日志作为附件上传(注意去除个人相关信息)。  
+2. 如进程异常，请将coredump功能开启，上传coredump信息文件，同时上传配套的smartdns进程文件。  
 在自定义界面，开启设置->自定义设置->生成coredump配置，重现问题后提交coredump文件
 coredump文件在/tmp目录下

--- a/40
+++ b/40
@@ -1,35 +1,41 @@
 FROM ubuntu:latest as smartdns-builder
 LABEL previous-stage=smartdns-builder
-COPY . /smartdns/
+
+# prepare builder
+ARG OPENSSL_VER=1.1.1f
 RUN apt update && \
-    apt install -y perl wget make musl-tools musl-dev && \
-    OPENSSL_VER=1.1.1f && \
-    mkdir /build -p && \
+    apt install -y perl curl make musl-tools musl-dev && \
    ln -s /usr/include/linux /usr/include/$(uname -m)-linux-musl && \
    ln -s /usr/include/asm-generic /usr/include/$(uname -m)-linux-musl && \
    ln -s /usr/include/$(uname -m)-linux-gnu/asm /usr/include/$(uname -m)-linux-musl && \
-    cd /build && \
-    wget http://archive.ubuntu.com/ubuntu/pool/main/o/openssl/openssl_${OPENSSL_VER}.orig.tar.gz && \
-    tar xf openssl_${OPENSSL_VER}.orig.tar.gz && \
-    cd openssl-${OPENSSL_VER} && \
+    \
+    mkdir -p /build/openssl && \
+    cd /build/openssl && \
+    curl -sSL http://archive.ubuntu.com/ubuntu/pool/main/o/openssl/openssl_${OPENSSL_VER}.orig.tar.gz | tar --strip-components=1 -zxv && \
+    \
    export CC=musl-gcc && \
    if [ "$(uname -m)" = "aarch64" ]; then \
        ./config --prefix=/opt/build no-tests -mno-outline-atomics ; \
    else \ 
-        ./config --prefix=/opt/build no-tests; \
+        ./config --prefix=/opt/build no-tests ; \
    fi && \
    make all -j8 && make install_sw && \
-    cd /smartdns && \
+    cd / && rm -rf /build
+
+# do make
+COPY . /build/smartdns/
+RUN cd /build/smartdns && \
+    export CC=musl-gcc && \
    export CFLAGS="-I /opt/build/include" && \
    export LDFLAGS="-L /opt/build/lib" && \
    sh ./package/build-pkg.sh --platform linux --arch `dpkg --print-architecture` --static && \
-    mkdir /release -p && \
-    cd /smartdns/package && tar xf *.tar.gz && \
-    cp /smartdns/package/smartdns/etc /release/ -a && \
-    cp /smartdns/package/smartdns/usr /release/ -a && \
-    chmod +x /release/etc/init.d/smartdns && \
-    mkdir /release/var/log/ /release/var/run/ -p && \
-    rm -fr /build /smartdns
+    \
+    ( cd package && tar -xvf *.tar.gz && chmod a+x smartdns/etc/init.d/smartdns ) && \
+    \
+    mkdir -p /release/var/log /release/var/run && \
+    cp package/smartdns/etc /release/ -a && \
+    cp package/smartdns/usr /release/ -a && \
+    cd / && rm -rf /build

 FROM busybox:latest
 COPY --from=smartdns-builder /release/ /
--- a/ReadMe.md
+++ b/ReadMe.md
@@ -548,6 +548,8 @@ rtt min/avg/max/mdev = 5.954/6.133/6.313/0.195 ms

 ## 配置文件说明

+配置建议：**smartdns默认已设置为最优模式，适合大部分场景的DNS查询体验改善，一般情况只需要增加上游服务器地址即可，无需做其他配置修改；如有其他配置修改，请务必了解其用途，避免修改后起到反作用。**
+
 | 键名 | 功能说明 | 默认值 | 可用值/要求 | 举例 |
 | :--- | :--- | :--- | :--- | :--- |
 | server-name | DNS 服务器名称 | 操作系统主机名 / smartdns | 符合主机名规格的字符串 | server-name smartdns |
@@ -563,11 +565,11 @@ rtt min/avg/max/mdev = 5.954/6.133/6.313/0.195 ms
 | rr-ttl-reply-max | 允许返回给客户端的最大 TTL 值 | 远程查询结果 | 大于 0 的数字 | rr-ttl-reply-max 60 |
 | max-reply-ip-num | 允许返回给客户的最大IP数量 | IP数量 | 大于 0 的数字 | max-reply-ip-num 1 |
 | log-level | 设置日志级别 | error | fatal、error、warn、notice、info 或 debug | log-level error |
-| log-file | 日志文件路径 | /var/log/smartdns.log | 合法路径字符串 | log-file /var/log/smartdns.log |
+| log-file | 日志文件路径 | /var/log/smartdns/smartdns.log | 合法路径字符串 | log-file /var/log/smartdns/smartdns.log |
 | log-size | 日志大小 | 128K | 数字 + K、M 或 G | log-size 128K |
 | log-num | 日志归档个数 | 2 | 大于等于 0 的数字 | log-num 2 |
 | audit-enable | 设置审计启用 | no | [yes\|no] | audit-enable yes |
-| audit-file | 审计文件路径 | /var/log/smartdns-audit.log | 合法路径字符串 | audit-file /var/log/smartdns-audit.log |
+| audit-file | 审计文件路径 | /var/log/smartdns/smartdns-audit.log | 合法路径字符串 | audit-file /var/log/smartdns/smartdns-audit.log |
 | audit-size | 审计大小 | 128K | 数字 + K、M 或 G | audit-size 128K |
 | audit-num | 审计归档个数 | 2 | 大于等于 0 的数字 | audit-num 2 |
 | conf-file | 附加配置文件 | 无 | 合法路径字符串 | conf-file /etc/smartdns/smartdns.more.conf |
@@ -576,6 +578,7 @@ rtt min/avg/max/mdev = 5.954/6.133/6.313/0.195 ms
 | server-tls | 上游 TLS DNS | 无 | 可重复。<br>[ip][:port]：服务器 IP:端口（可选)<br>[-spki-pin [sha256-pin]]：TLS 合法性校验 SPKI 值，base64 编码的 sha256 SPKI pin 值<br>[-host-name]：TLS SNI 名称<br>[-tls-host-verify]：TLS 证书主机名校验<br> [-no-check-certificate]：跳过证书校验<br>[-blacklist-ip]：配置 IP 过滤结果<br>[-whitelist-ip]：仅接受参数中配置的 IP 范围<br>[-group [group] ...]：DNS 服务器所属组，比如 office 和 foreign，和 nameserver 配套使用<br>[-exclude-default-group]：将 DNS 服务器从默认组中排除 | server-tls 8.8.8.8:853 |
 | server-https | 上游 HTTPS DNS | 无 | 可重复。<br>https://[host][:port]/path：服务器 IP:端口（可选）<br>[-spki-pin [sha256-pin]]：TLS 合法性校验 SPKI 值，base64 编码的 sha256 SPKI pin 值<br>[-host-name]：TLS SNI 名称<br>[-http-host]：http 协议头主机名<br>[-tls-host-verify]：TLS 证书主机名校验<br> [-no-check-certificate]：跳过证书校验<br>[-blacklist-ip]：配置 IP 过滤结果<br>[-whitelist-ip]：仅接受参数中配置的 IP 范围。<br>[-group [group] ...]：DNS 服务器所属组，比如 office 和 foreign，和 nameserver 配套使用<br>[-exclude-default-group]：将 DNS 服务器从默认组中排除 | server-https https://cloudflare-dns.com/dns-query |
 | speed-check-mode | 测速模式选择 | 无 | [ping\|tcp:[80]\|none] | speed-check-mode ping,tcp:80,tcp:443 |
+| response-mode | 首次查询响应模式 | first-ping |模式：[fisrt-ping\|fastest-ip\|first-response]<br> [first-ping]: 最快ping响应地址模式，DNS上游最快查询时延+ping时延最短，查询等待与链接体验最佳;<br>[fastest-ip]: 最快IP地址模式，查询到的所有IP地址中ping最短的IP。需等待IP测速; <br>[first-response]: 最快响应的DNS结果，DNS查询等待时间最短，返回的IP地址可能不是最快。| response-mode first-ping |
 | address | 指定域名 IP 地址 | 无 | address /domain/[ip\|-\|-4\|-6\|#\|#4\|#6] <br>- 表示忽略 <br># 表示返回 SOA <br>4 表示 IPv4 <br>6 表示 IPv6 | address /www.example.com/1.2.3.4 |
 | nameserver | 指定域名使用 server 组解析 | 无 | nameserver /domain/[group\|-], group 为组名，- 表示忽略此规则，配套 server 中的 -group 参数使用 | nameserver /www.example.com/office |
 | ipset | 域名 ipset | 无 | ipset /domain/[ipset\|-\|#[4\|6]:[ipset\|-][,#[4\|6]:[ipset\|-]]]，-表示忽略 | ipset /www.example.com/#4:dns4,#6:- |
@@ -594,6 +597,7 @@ rtt min/avg/max/mdev = 5.954/6.133/6.313/0.195 ms
 | serve-expired-reply-ttl | 回应的过期缓存 TTL | 5 | 秒，0 表示停用超时，大于 0 表示指定的超时的秒数 | serve-expired-reply-ttl 30 |
 | dualstack-ip-selection | 双栈 IP 优选 | yes | [yes\|no] | dualstack-ip-selection yes |
 | dualstack-ip-selection-threshold | 双栈 IP 优选阈值 | 15ms | 单位为毫秒（ms） | dualstack-ip-selection-threshold [0-1000] |
+| user | 进程运行用户 | root | user [username] | user nobody |
 | ca-file | 证书文件 | /etc/ssl/certs/ca-certificates.crt | 合法路径字符串 | ca-file /etc/ssl/certs/ca-certificates.crt |
 | ca-path | 证书文件路径 | /etc/ssl/certs | 合法路径字符串 | ca-path /etc/ssl/certs |

--- a/ReadMe_en.md
+++ b/ReadMe_en.md
@@ -501,11 +501,11 @@ Note: Merlin firmware is derived from ASUS firmware and can theoretically be use
 |rr-ttl-max|Domain name Maximum TTL|Remote query result|number greater than 0|rr-ttl-max 600
 |max-reply-ip-num|Maximum number of IPs returned to the client|8|number of IPs, 1~16 |max-reply-ip-num 1
 |log-level|log level|error|fatal,error,warn,notice,info,debug|log-level error
-|log-file|log path|/var/log/smartdns.log|File Pah|log-file /var/log/smartdns.log
+|log-file|log path|/var/log/smartdns/smartdns.log|File Pah|log-file /var/log/smartdns/smartdns.log
 |log-size|log size|128K|number+K,M,G|log-size 128K
 |log-num|archived log number|2|Integer|log-num 2
 |audit-enable|audit log enable|no|[yes\|no]|audit-enable yes
-|audit-file|audit log file|/var/log/smartdns-audit.log|File Path|audit-file /var/log/smartdns-audit.log
+|audit-file|audit log file|/var/log/smartdns/smartdns-audit.log|File Path|audit-file /var/log/smartdns/smartdns-audit.log
 |audit-size|audit log size|128K|number+K,M,G|audit-size 128K
 |audit-num|archived audit log number|2|Integer|audit-num 2
 |conf-file|additional conf file|None|File path|conf-file /etc/smartdns/smartdns.more.conf
@@ -514,6 +514,7 @@ Note: Merlin firmware is derived from ASUS firmware and can theoretically be use
 |server-tls|Upstream TLS DNS server|None|Repeatable <br>`[ip][:port]`: Server IP, port optional. <br>`[-spki-pin [sha256-pin]]`: TLS verify SPKI value, a base64 encoded SHA256 hash<br>`[-host-name]`:TLS Server name. <br>`[-tls-host-verify]`: TLS cert hostname to verify. <br>`-no-check-certificate:`: No check certificate. <br>`[-blacklist-ip]`: The "-blacklist-ip" parameter is to filtering IPs which is configured by "blacklist-ip". <br>`[-whitelist-ip]`: whitelist-ip parameter specifies that only the IP range configured in whitelist-ip is accepted. <br>`[-group [group] ...]`: The group to which the DNS server belongs, such as office, foreign, use with nameserver. <br>`[-exclude-default-group]`: Exclude DNS servers from the default group| server-tls 8.8.8.8:853
 |server-https|Upstream HTTPS DNS server|None|Repeatable <br>`https://[host][:port]/path`: Server IP, port optional. <br>`[-spki-pin [sha256-pin]]`: TLS verify SPKI value, a base64 encoded SHA256 hash<br>`[-host-name]`:TLS Server name<br>`[-http-host]`：http header host. <br>`[-tls-host-verify]`: TLS cert hostname to verify. <br>`-no-check-certificate:`: No check certificate. <br>`[-blacklist-ip]`: The "-blacklist-ip" parameter is to filtering IPs which is configured by "blacklist-ip". <br>`[-whitelist-ip]`: whitelist-ip parameter specifies that only the IP range configured in whitelist-ip is accepted. <br>`[-group [group] ...]`: The group to which the DNS server belongs, such as office, foreign, use with nameserver. <br>`[-exclude-default-group]`: Exclude DNS servers from the default group| server-https https://cloudflare-dns.com/dns-query
 |speed-check-mode|Speed mode|None|[ping\|tcp:[80]\|none]|speed-check-mode ping,tcp:80,tcp:443
+|response-mode|First query response mode|first-ping|Mode: [fisrt-ping\|fastest-ip\|first-response]<br> [first-ping]: The fastest dns + ping response mode, DNS query delay + ping delay is the shortest;<br>[fastest-ip]: The fastest IP address mode, return the fastest ip address, may take some time to test speed. <br>[first-response]: The fastest response DNS result mode, the DNS query waiting time is the shortest. | response-mode first-ping |
 |address|Domain IP address|None|address /domain/[ip\|-\|-4\|-6\|#\|#4\|#6], `-` for ignore, `#` for return SOA, `4` for IPV4, `6` for IPV6| address /www.example.com/1.2.3.4
 |nameserver|To query domain with specific server group|None|nameserver /domain/[group\|-], `group` is the group name, `-` means ignore this rule, use the `-group` parameter in the related server|nameserver /www.example.com/office
 |ipset|Domain IPSet|None|ipset /domain/[ipset\|-\|#[4\|6]:[ipset\|-][,#[4\|6]:[ipset\|-]]], `-` for ignore|ipset /www.example.com/#4:dns4,#6:-
@@ -532,6 +533,7 @@ Note: Merlin firmware is derived from ASUS firmware and can theoretically be use
 |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|yes|[yes\|no]|dualstack-ip-selection yes
 |dualstack-ip-selection-threshold|Dualstack ip select threadhold|15ms|millisecond|dualstack-ip-selection-threshold [0-1000]
+|user|run as user|root|user [username]|user nobody
 |ca-file|certificate file|/etc/ssl/certs/ca-certificates.crt|path|ca-file /etc/ssl/certs/ca-certificates.crt
 |ca-path|certificates path|/etc/ssl/certs|path|ca-path /etc/ssl/certs

--- a/etc/smartdns/smartdns.conf
+++ b/etc/smartdns/smartdns.conf
@@ -4,7 +4,7 @@
 #   server-name smartdns
 #

-# dns server run ser
+# dns server run user
 # user [username]
 # example: run as nobody
 #   user nobody
@@ -109,7 +109,7 @@ cache-size 16384
 # rr-ttl: ttl for all record
 # rr-ttl-min: minimum ttl for resource record
 # rr-ttl-max: maximum ttl for resource record
-# tr-ttl-reply-max: maximum reply ttl for resource record
+# rr-ttl-reply-max: maximum reply ttl for resource record
 # example:
 # rr-ttl 300
 # rr-ttl-min 60
@@ -120,13 +120,17 @@ cache-size 16384
 # example:
 # max-reply-ip-num 1

+# response mode
+# Experimental feature
+# response-mode [first-ping|fastest-ip|fastest-response]
+
 # set log level
 # log-level: [level], level=fatal, error, warn, notice, info, debug
 # log-file: file path of log file.
 # log-size: size of each log file, support k,m,g
 # log-num: number of logs
 log-level info
-# log-file /var/log/smartdns.log
+# log-file /var/log/smartdns/smartdns.log
 # log-size 128k
 # log-num 2

--- a/src/Makefile
+++ b/src/Makefile
@@ -20,7 +20,7 @@ OBJS=smartdns.o fast_ping.o dns_client.o dns_server.o dns.o util.o tlog.o dns_co

 # cflags
 ifndef CFLAGS
-CFLAGS =-O2 -g -Wall -Wstrict-prototypes -fno-omit-frame-pointer -Wstrict-aliasing -funwind-tables
+CFLAGS =-O2 -g -Wall -Wstrict-prototypes -fno-omit-frame-pointer -Wstrict-aliasing -funwind-tables -Wmissing-prototypes -Wshadow -Wextra -Wno-unused-parameter -Wno-implicit-fallthrough
 endif
 override CFLAGS +=-Iinclude
 override CFLAGS += -DBASE_FILE_NAME=\"$(notdir $<)\"
--- a/src/dns.c
+++ b/src/dns.c
@@ -45,7 +45,7 @@
 /* read short and move pointer */
 static short _dns_read_short(unsigned char **buffer)
 {
-	unsigned short value;
+	unsigned short value = 0;

 	value = ntohs(*((unsigned short *)(*buffer)));
 	*buffer += 2;
@@ -86,7 +86,7 @@ static void _dns_write_int(unsigned char **buffer, unsigned int value)
 /* read int and move pointer */
 static unsigned int _dns_read_int(unsigned char **buffer)
 {
-	unsigned int value;
+	unsigned int value = 0;

 	value = ntohl(*((unsigned int *)(*buffer)));
 	*buffer += 4;
@@ -99,12 +99,13 @@ static inline int _dns_left_len(struct dns_context *context)
 	return context->maxsize - (context->ptr - context->data);
 }

-static int _dns_get_domain_from_packet(unsigned char *packet, int packet_size, unsigned char **domain_ptr, char *output, int size)
+static int _dns_get_domain_from_packet(unsigned char *packet, int packet_size, unsigned char **domain_ptr, char *output,
+									   int size)
 {
 	int output_len = 0;
 	int copy_len = 0;
 	int len = 0;
-	unsigned char *ptr = (unsigned char*)*domain_ptr;
+	unsigned char *ptr = *domain_ptr;
 	int is_compressed = 0;
 	int ptr_jump = 0;

@@ -140,8 +141,8 @@ static int _dns_get_domain_from_packet(unsigned char *packet, int packet_size, u

 			ptr = packet + len;
 			if (ptr > packet + packet_size) {
-				tlog(TLOG_DEBUG, "length is not enough %u:%ld, %p, %p", packet_size, (long)(ptr - packet),
-					 *domain_ptr, packet);
+				tlog(TLOG_DEBUG, "length is not enough %u:%ld, %p, %p", packet_size, (long)(ptr - packet), *domain_ptr,
+					 packet);
 				return -1;
 			}
 			is_compressed = 1;
@@ -159,8 +160,8 @@ static int _dns_get_domain_from_packet(unsigned char *packet, int packet_size, u
 		}

 		if (ptr > packet + packet_size) {
-			tlog(TLOG_DEBUG, "length is not enough %u:%ld, %p, %p", packet_size, (long)(ptr - packet),
-				 *domain_ptr, packet);
+			tlog(TLOG_DEBUG, "length is not enough %u:%ld, %p, %p", packet_size, (long)(ptr - packet), *domain_ptr,
+				 packet);
 			return -1;
 		}

@@ -169,8 +170,8 @@ static int _dns_get_domain_from_packet(unsigned char *packet, int packet_size, u
 			/* copy sub string */
 			copy_len = (len < size - output_len) ? len : size - 1 - output_len;
 			if ((ptr + copy_len) > (packet + packet_size)) {
-				tlog(TLOG_DEBUG, "length is not enough %u:%ld, %p, %p", packet_size, (long)(ptr - packet),
-					 *domain_ptr, packet);
+				tlog(TLOG_DEBUG, "length is not enough %u:%ld, %p, %p", packet_size, (long)(ptr - packet), *domain_ptr,
+					 packet);
 				return -1;
 			}
 			memcpy(output, ptr, copy_len);
@@ -190,18 +191,20 @@ static int _dns_get_domain_from_packet(unsigned char *packet, int packet_size, u

 static int _dns_decode_domain(struct dns_context *context, char *output, int size)
 {
-	return _dns_get_domain_from_packet(context->data, context->maxsize, &(context->ptr), output, size);		
+	return _dns_get_domain_from_packet(context->data, context->maxsize, &(context->ptr), output, size);
 }

-unsigned int dict_hash(const char *s)
+static unsigned int dict_hash(const char *s)
 {
-    unsigned int hashval;
-    for (hashval = 0; *s != '\0'; s++)
-      hashval = *s + 31 * hashval;
-    return hashval;
+	unsigned int hashval = 0;
+	for (hashval = 0; *s != '\0'; s++) {
+		hashval = *s + 31 * hashval;
+	}
+	return hashval;
 }

-int _dns_add_domain_dict(struct dns_context *context, unsigned int hash, int pos) {
+static int _dns_add_domain_dict(struct dns_context *context, unsigned int hash, int pos)
+{
 	struct dns_packet_dict *dict = context->namedict;

 	if (dict->dict_count >= DNS_PACKET_DICT_SIZE) {
@@ -224,7 +227,8 @@ int _dns_add_domain_dict(struct dns_context *context, unsigned int hash, int pos
 	return 0;
 }

-int _dns_get_domain_offset(struct dns_context *context, const char *domain) {
+static int _dns_get_domain_offset(struct dns_context *context, const char *domain)
+{
 	int i = 0;

 	char domain_check[DNS_MAX_CNAME_LEN];
@@ -241,7 +245,8 @@ int _dns_get_domain_offset(struct dns_context *context, const char *domain) {
 		}

 		unsigned char *domain_check_ptr = dict->names[i].pos + context->data;
-		if (_dns_get_domain_from_packet(context->data, context->maxsize, &domain_check_ptr, domain_check, DNS_MAX_CNAME_LEN) !=0) {
+		if (_dns_get_domain_from_packet(context->data, context->maxsize, &domain_check_ptr, domain_check,
+										DNS_MAX_CNAME_LEN) != 0) {
 			return -1;
 		}

@@ -252,7 +257,7 @@ int _dns_get_domain_offset(struct dns_context *context, const char *domain) {
 	return -1;
 }

-static int _dns_encode_domain(struct dns_context *context, char *domain)
+static int _dns_encode_domain(struct dns_context *context, const char *domain)
 {
 	int num = 0;
 	int total_len = 0;
@@ -269,7 +274,6 @@ static int _dns_encode_domain(struct dns_context *context, char *domain)
 			int offset = 0xc000 | dict_offset;
 			_dns_write_short(&ptr_num, offset);
 			context->ptr++;
-			dict_offset = -1;
 			ptr_num = NULL;
 			return total_len;
 		}
@@ -308,7 +312,7 @@ static int _dns_encode_domain(struct dns_context *context, char *domain)
 /* iterator get rrs begin */
 struct dns_rrs *dns_get_rrs_start(struct dns_packet *packet, dns_rr_type type, int *count)
 {
-	unsigned short start;
+	unsigned short start = 0;
 	struct dns_head *head = &packet->head;

 	/* get rrs count by rrs type */
@@ -338,7 +342,7 @@ struct dns_rrs *dns_get_rrs_start(struct dns_packet *packet, dns_rr_type type, i
 		break;
 	}

-	/* if not resource record, reutrn null */
+	/* if not resource record, return null */
 	if (start == DNS_RR_END) {
 		return NULL;
 	}
@@ -357,8 +361,9 @@ struct dns_rrs *dns_get_rrs_next(struct dns_packet *packet, struct dns_rrs *rrs)
 	return (struct dns_rrs *)(packet->data + rrs->next);
 }

-static void _dns_init_context_by_rrs(struct dns_rrs *rrs, struct dns_context *context) {
-	context->packet =rrs->packet;
+static void _dns_init_context_by_rrs(struct dns_rrs *rrs, struct dns_context *context)
+{
+	context->packet = rrs->packet;
 	context->data = rrs->packet->data;
 	context->ptr = rrs->data;
 	context->namedict = &rrs->packet->namedict;
@@ -368,10 +373,10 @@ static void _dns_init_context_by_rrs(struct dns_rrs *rrs, struct dns_context *co
 /* iterator add rrs begin */
 static int _dns_add_rrs_start(struct dns_packet *packet, struct dns_context *context)
 {
-	struct dns_rrs *rrs;
+	struct dns_rrs *rrs = NULL;
 	unsigned char *end = packet->data + packet->len;

-	if ((packet->len + sizeof(*rrs)) >= packet->size) {
+	if ((packet->len + (int)sizeof(*rrs)) >= packet->size) {
 		return -1;
 	}
 	rrs = (struct dns_rrs *)end;
@@ -388,15 +393,15 @@ static int _dns_add_rrs_start(struct dns_packet *packet, struct dns_context *con
 /* iterator add rrs end */
 static int _dns_rr_add_end(struct dns_packet *packet, int type, dns_type_t rtype, int len)
 {
-	struct dns_rrs *rrs;
-	struct dns_rrs *rrs_next;
+	struct dns_rrs *rrs = NULL;
+	struct dns_rrs *rrs_next = NULL;
 	struct dns_head *head = &packet->head;
 	unsigned char *end = packet->data + packet->len;
-	unsigned short *count;
-	unsigned short *start;
+	unsigned short *count = NULL;
+	unsigned short *start = NULL;

 	rrs = (struct dns_rrs *)end;
-	if (packet->len + len > packet->size - sizeof(*packet) - sizeof(*rrs)) {
+	if (packet->len + len > packet->size - (int)sizeof(*packet) - (int)sizeof(*rrs)) {
 		return -1;
 	}

@@ -426,7 +431,7 @@ static int _dns_rr_add_end(struct dns_packet *packet, int type, dns_type_t rtype
 		break;
 	}

-	/* add data to end of dns_packet, and set previouse rrs point to this rrs */
+	/* add data to end of dns_packet, and set previous rrs point to this rrs */
 	if (*start != DNS_RR_END) {
 		rrs_next = (struct dns_rrs *)(packet->data + *start);
 		while (rrs_next->next != DNS_RR_END) {
@@ -449,7 +454,7 @@ static int _dns_rr_add_end(struct dns_packet *packet, int type, dns_type_t rtype
 	return 0;
 }

-static int _dns_add_qr_head(struct dns_context *context, char *domain, int qtype, int qclass)
+static int _dns_add_qr_head(struct dns_context *context, const char *domain, int qtype, int qclass)
 {
 	int ret = _dns_encode_domain(context, domain);
 	if (ret < 0) {
@@ -473,7 +478,7 @@ static int _dns_get_qr_head(struct dns_context *context, char *domain, int maxsi
 	if (domain == NULL || context == NULL) {
 		return -1;
 	}
-	
+
 	ret = _dns_decode_domain(context, domain, maxsize);
 	if (ret < 0) {
 		return -1;
@@ -489,8 +494,7 @@ static int _dns_get_qr_head(struct dns_context *context, char *domain, int maxsi
 	return 0;
 }

-static int _dns_add_rr_head(struct dns_context *context, char *domain, int qtype, int qclass, int ttl,
-							int rr_len)
+static int _dns_add_rr_head(struct dns_context *context, const char *domain, int qtype, int qclass, int ttl, int rr_len)
 {
 	int len = 0;

@@ -515,8 +519,8 @@ static int _dns_add_rr_head(struct dns_context *context, char *domain, int qtype
 	return len + 6;
 }

-static int _dns_get_rr_head(struct dns_context *context, char *domain, int maxsize, int *qtype, int *qclass,
-							int *ttl, int *rr_len)
+static int _dns_get_rr_head(struct dns_context *context, char *domain, int maxsize, int *qtype, int *qclass, int *ttl,
+							int *rr_len)
 {
 	int len = 0;

@@ -538,12 +542,12 @@ static int _dns_get_rr_head(struct dns_context *context, char *domain, int maxsi
 	return len;
 }

-static int _dns_add_RAW(struct dns_packet *packet, dns_rr_type rrtype, dns_type_t rtype, char *domain, int ttl,
-						void *raw, int raw_len)
+static int _dns_add_RAW(struct dns_packet *packet, dns_rr_type rrtype, dns_type_t rtype, const char *domain, int ttl,
+						const void *raw, int raw_len)
 {
 	int len = 0;
 	struct dns_context context;
-	int ret;
+	int ret = 0;

 	/* resource record */
 	/* |domain          |
@@ -621,7 +625,7 @@ static int _dns_add_opt_RAW(struct dns_packet *packet, dns_opt_code_t opt_rrtype
 	len += raw_len;
 	len += sizeof(*opt);

-	return _dns_add_RAW(packet, DNS_RRS_OPT, DNS_OPT_T_TCP_KEEPALIVE, "", 0, opt_data, len);
+	return _dns_add_RAW(packet, DNS_RRS_OPT, (dns_type_t)DNS_OPT_T_TCP_KEEPALIVE, "", 0, opt_data, len);
 }

 static int _dns_get_opt_RAW(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, struct dns_opt *dns_opt,
@@ -715,7 +719,7 @@ static int __attribute__((unused)) _dns_get_OPT(struct dns_rrs *rrs, unsigned sh
 	return 0;
 }

-int dns_add_CNAME(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, char *cname)
+int dns_add_CNAME(struct dns_packet *packet, dns_rr_type type, const char *domain, int ttl, const char *cname)
 {
 	int rr_len = strnlen(cname, DNS_MAX_CNAME_LEN) + 1;
 	return _dns_add_RAW(packet, type, DNS_T_CNAME, domain, ttl, cname, rr_len);
@@ -727,7 +731,8 @@ int dns_get_CNAME(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, char
 	return _dns_get_RAW(rrs, domain, maxsize, ttl, cname, &len);
 }

-int dns_add_A(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, unsigned char addr[DNS_RR_A_LEN])
+int dns_add_A(struct dns_packet *packet, dns_rr_type type, const char *domain, int ttl,
+			  unsigned char addr[DNS_RR_A_LEN])
 {
 	return _dns_add_RAW(packet, type, DNS_T_A, domain, ttl, addr, DNS_RR_A_LEN);
 }
@@ -738,7 +743,7 @@ int dns_get_A(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, unsigned
 	return _dns_get_RAW(rrs, domain, maxsize, ttl, addr, &len);
 }

-int dns_add_PTR(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, char *cname)
+int dns_add_PTR(struct dns_packet *packet, dns_rr_type type, const char *domain, int ttl, char *cname)
 {
 	int rr_len = strnlen(cname, DNS_MAX_CNAME_LEN) + 1;
 	return _dns_add_RAW(packet, type, DNS_T_PTR, domain, ttl, cname, rr_len);
@@ -750,7 +755,7 @@ int dns_get_PTR(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, char *
 	return _dns_get_RAW(rrs, domain, maxsize, ttl, cname, &len);
 }

-int dns_add_NS(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, char *cname)
+int dns_add_NS(struct dns_packet *packet, dns_rr_type type, const char *domain, int ttl, const char *cname)
 {
 	int rr_len = strnlen(cname, DNS_MAX_CNAME_LEN) + 1;
 	return _dns_add_RAW(packet, type, DNS_T_NS, domain, ttl, cname, rr_len);
@@ -762,7 +767,7 @@ int dns_get_NS(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, char *c
 	return _dns_get_RAW(rrs, domain, maxsize, ttl, cname, &len);
 }

-int dns_add_AAAA(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl,
+int dns_add_AAAA(struct dns_packet *packet, dns_rr_type type, const char *domain, int ttl,
 				 unsigned char addr[DNS_RR_AAAA_LEN])
 {
 	return _dns_add_RAW(packet, type, DNS_T_AAAA, domain, ttl, addr, DNS_RR_AAAA_LEN);
@@ -774,7 +779,7 @@ int dns_get_AAAA(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, unsig
 	return _dns_get_RAW(rrs, domain, maxsize, ttl, addr, &len);
 }

-int dns_add_SOA(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, struct dns_soa *soa)
+int dns_add_SOA(struct dns_packet *packet, dns_rr_type type, const char *domain, int ttl, struct dns_soa *soa)
 {
 	/* SOA */
 	/*| mname        |
@@ -845,7 +850,6 @@ int dns_get_SOA(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, struct
 	memcpy(&soa->expire, ptr, 4);
 	ptr += 4;
 	memcpy(&soa->minimum, ptr, 4);
-	ptr += 4;

 	return 0;
 }
@@ -881,7 +885,7 @@ int dns_add_OPT_ECS(struct dns_packet *packet, struct dns_opt_ecs *ecs)
 	memcpy(opt->data, ecs, len);
 	len += sizeof(*opt);

-	return _dns_add_RAW(packet, DNS_RRS_OPT, DNS_OPT_T_ECS, "", 0, opt_data, len);
+	return _dns_add_RAW(packet, DNS_RRS_OPT, (dns_type_t)DNS_OPT_T_ECS, "", 0, opt_data, len);
 }

 int dns_get_OPT_ECS(struct dns_rrs *rrs, unsigned short *opt_code, unsigned short *opt_len, struct dns_opt_ecs *ecs)
@@ -896,7 +900,7 @@ int dns_get_OPT_ECS(struct dns_rrs *rrs, unsigned short *opt_code, unsigned shor
 		return -1;
 	}

-	if (len < sizeof(*opt)) {
+	if (len < (int)sizeof(*opt)) {
 		return -1;
 	}

@@ -934,7 +938,7 @@ int dns_get_OPT_TCP_KEEYALIVE(struct dns_rrs *rrs, unsigned short *opt_code, uns
 		return -1;
 	}

-	if (len < sizeof(*opt)) {
+	if (len < (int)sizeof(*opt)) {
 		return -1;
 	}

@@ -962,7 +966,7 @@ int dns_get_OPT_TCP_KEEYALIVE(struct dns_rrs *rrs, unsigned short *opt_code, uns
 * Format:
 * |DNS_NAME\0(string)|qtype(short)|qclass(short)|
 */
-int dns_add_domain(struct dns_packet *packet, char *domain, int qtype, int qclass)
+int dns_add_domain(struct dns_packet *packet, const char *domain, int qtype, int qclass)
 {
 	int len = 0;
 	int ret = 0;
@@ -995,7 +999,7 @@ int dns_get_domain(struct dns_rrs *rrs, char *domain, int maxsize, int *qtype, i

 static int _dns_decode_head(struct dns_context *context)
 {
-	unsigned int fields;
+	unsigned int fields = 0;
 	int len = 12;
 	struct dns_head *head = &context->packet->head;

@@ -1152,7 +1156,8 @@ static int _dns_decode_rr_head(struct dns_context *context, char *domain, int do
 	return 0;
 }

-static int _dns_encode_rr_head(struct dns_context *context, char *domain, int qtype, int qclass, int ttl, int rr_len, unsigned char **rr_len_ptr)
+static int _dns_encode_rr_head(struct dns_context *context, char *domain, int qtype, int qclass, int ttl, int rr_len,
+							   unsigned char **rr_len_ptr)
 {
 	int ret = 0;
 	ret = _dns_encode_qr_head(context, domain, qtype, qclass);
@@ -1175,12 +1180,12 @@ static int _dns_encode_rr_head(struct dns_context *context, char *domain, int qt

 static int _dns_encode_raw(struct dns_context *context, struct dns_rrs *rrs)
 {
-	int ret;
+	int ret = 0;
 	int qtype = 0;
 	int qclass = 0;
 	int ttl = 0;
 	char domain[DNS_MAX_CNAME_LEN];
-	int rr_len;
+	int rr_len = 0;
 	unsigned char *rr_len_ptr = NULL;
 	struct dns_context data_context;
 	/*
@@ -1250,12 +1255,12 @@ static int _dns_decode_CNAME(struct dns_context *context, char *cname, int cname

 static int _dns_encode_CNAME(struct dns_context *context, struct dns_rrs *rrs)
 {
-	int ret;
+	int ret = 0;
 	int qtype = 0;
 	int qclass = 0;
 	int ttl = 0;
 	char domain[DNS_MAX_CNAME_LEN];
-	int rr_len;
+	int rr_len = 0;
 	unsigned char *rr_len_ptr = NULL;
 	struct dns_context data_context;

@@ -1315,7 +1320,7 @@ static int _dns_decode_SOA(struct dns_context *context, struct dns_soa *soa)

 static int _dns_encode_SOA(struct dns_context *context, struct dns_rrs *rrs)
 {
-	int ret;
+	int ret = 0;
 	int qtype = 0;
 	int qclass = 0;
 	int ttl = 0;
@@ -1391,7 +1396,7 @@ static int _dns_decode_opt_ecs(struct dns_context *context, struct dns_opt_ecs *
 	len = (ecs->source_prefix / 8);
 	len += (ecs->source_prefix % 8 > 0) ? 1 : 0;

-	if (_dns_left_len(context) < len || len > sizeof(ecs->addr)) {
+	if (_dns_left_len(context) < len || len > (int)sizeof(ecs->addr)) {
 		return -1;
 	}

@@ -1405,7 +1410,6 @@ static int _dns_decode_opt_ecs(struct dns_context *context, struct dns_opt_ecs *
 	return 0;
 }

-
 static int _dns_decode_opt_cookie(struct dns_context *context, struct dns_opt_cookie *cookie)
 {
 	// TODO
@@ -1436,16 +1440,15 @@ static int _dns_decode_opt_cookie(struct dns_context *context, struct dns_opt_co
 	return 0;
 }

-
 static int _dns_encode_OPT(struct dns_context *context, struct dns_rrs *rrs)
 {
-	int ret;
+	int ret = 0;
 	int opt_code = 0;
 	int qclass = 0;
 	char domain[DNS_MAX_CNAME_LEN];
 	struct dns_context data_context;
 	int rr_len = 0;
-	int ttl;
+	int ttl = 0;
 	struct dns_opt *dns_opt = NULL;

 	_dns_init_context_by_rrs(rrs, &data_context);
@@ -1454,7 +1457,7 @@ static int _dns_encode_OPT(struct dns_context *context, struct dns_rrs *rrs)
 		return -1;
 	}

-	if (rr_len < sizeof(*dns_opt)) {
+	if (rr_len < (int)sizeof(*dns_opt)) {
 		return -1;
 	}

@@ -1493,8 +1496,8 @@ static int _dns_get_opts_data_len(struct dns_packet *packet, struct dns_rrs *rrs
 	int len = 0;
 	int opt_code = 0;
 	int qclass = 0;
-	int ttl;
-	int ret;
+	int ttl = 0;
+	int ret = 0;
 	char domain[DNS_MAX_CNAME_LEN];
 	struct dns_context data_context;
 	int rr_len = 0;
@@ -1550,10 +1553,10 @@ static int _dns_encode_opts(struct dns_packet *packet, struct dns_context *conte
 	return 0;
 }

-static int __attribute__((unused)) _dns_decode_opt(struct dns_context *context, dns_rr_type type, unsigned int ttl, int rr_len)
+static int _dns_decode_opt(struct dns_context *context, dns_rr_type type, unsigned int ttl, int rr_len)
 {
-	unsigned short opt_code;
-	unsigned short opt_len;
+	unsigned short opt_code = 0;
+	unsigned short opt_len = 0;
 	unsigned short ercode = (ttl >> 16) & 0xFFFF;
 	unsigned short ever = (ttl)&0xFFFF;
 	unsigned char *start = context->ptr;
@@ -1599,6 +1602,8 @@ static int __attribute__((unused)) _dns_decode_opt(struct dns_context *context,

 	while (context->ptr - start < rr_len) {
 		if (_dns_left_len(context) < 4) {
+			tlog(TLOG_WARN, "data length is invalid, %d:%d", _dns_left_len(context),
+				 (int)(context->ptr - context->data));
 			return -1;
 		}
 		opt_code = _dns_read_short(&context->ptr);
@@ -1646,7 +1651,7 @@ static int __attribute__((unused)) _dns_decode_opt(struct dns_context *context,
 static int _dns_decode_qd(struct dns_context *context)
 {
 	struct dns_packet *packet = context->packet;
-	int len;
+	int len = 0;
 	int qtype = 0;
 	int qclass = 0;
 	char domain[DNS_MAX_CNAME_LEN];
@@ -1666,14 +1671,14 @@ static int _dns_decode_qd(struct dns_context *context)

 static int _dns_decode_an(struct dns_context *context, dns_rr_type type)
 {
-	int ret;
+	int ret = 0;
 	int qtype = 0;
 	int qclass = 0;
-	int ttl;
+	int ttl = 0;
 	int rr_len = 0;
 	char domain[DNS_MAX_CNAME_LEN];
 	struct dns_packet *packet = context->packet;
-	unsigned char *start;
+	unsigned char *start = NULL;

 	/* decode rr head */
 	ret = _dns_decode_rr_head(context, domain, DNS_MAX_CNAME_LEN, &qtype, &qclass, &ttl, &rr_len);
@@ -1689,7 +1694,8 @@ static int _dns_decode_an(struct dns_context *context, dns_rr_type type)
 		unsigned char addr[DNS_RR_A_LEN];
 		ret = _dns_decode_raw(context, addr, sizeof(addr));
 		if (ret < 0) {
-			tlog(TLOG_ERROR, "decode A failed, %s", domain);
+			tlog(TLOG_DEBUG, "decode A failed, %s, len: %d:%d", domain, (int)(context->ptr - context->data),
+				 _dns_left_len(context));
 			return -1;
 		}

@@ -1703,7 +1709,8 @@ static int _dns_decode_an(struct dns_context *context, dns_rr_type type)
 		char cname[DNS_MAX_CNAME_LEN];
 		ret = _dns_decode_CNAME(context, cname, DNS_MAX_CNAME_LEN);
 		if (ret < 0) {
-			tlog(TLOG_ERROR, "decode CNAME failed, %s", domain);
+			tlog(TLOG_DEBUG, "decode CNAME failed, %s, len: %d:%d", domain, (int)(context->ptr - context->data),
+				 _dns_left_len(context));
 			return -1;
 		}

@@ -1717,13 +1724,13 @@ static int _dns_decode_an(struct dns_context *context, dns_rr_type type)
 		struct dns_soa soa;
 		ret = _dns_decode_SOA(context, &soa);
 		if (ret < 0) {
-			tlog(TLOG_ERROR, "decode CNAME failed, %s", domain);
+			tlog(TLOG_DEBUG, "decode SOA failed, %s", domain);
 			return -1;
 		}

 		ret = dns_add_SOA(packet, type, domain, ttl, &soa);
 		if (ret < 0) {
-			tlog(TLOG_ERROR, "add CNAME failed, %s", domain);
+			tlog(TLOG_ERROR, "add SOA failed, %s", domain);
 			return -1;
 		}
 	} break;
@@ -1731,7 +1738,7 @@ static int _dns_decode_an(struct dns_context *context, dns_rr_type type)
 		char ns[DNS_MAX_CNAME_LEN];
 		ret = _dns_decode_CNAME(context, ns, DNS_MAX_CNAME_LEN);
 		if (ret < 0) {
-			tlog(TLOG_ERROR, "decode NS failed, %s", domain);
+			tlog(TLOG_DEBUG, "decode NS failed, %s", domain);
 			return -1;
 		}

@@ -1745,7 +1752,7 @@ static int _dns_decode_an(struct dns_context *context, dns_rr_type type)
 		char name[DNS_MAX_CNAME_LEN];
 		ret = _dns_decode_CNAME(context, name, DNS_MAX_CNAME_LEN);
 		if (ret < 0) {
-			tlog(TLOG_ERROR, "decode PTR failed, %s", domain);
+			tlog(TLOG_DEBUG, "decode PTR failed, %s", domain);
 			return -1;
 		}

@@ -1759,7 +1766,7 @@ static int _dns_decode_an(struct dns_context *context, dns_rr_type type)
 		unsigned char addr[DNS_RR_AAAA_LEN];
 		ret = _dns_decode_raw(context, addr, sizeof(addr));
 		if (ret < 0) {
-			tlog(TLOG_ERROR, "decode AAAA failed, %s", domain);
+			tlog(TLOG_DEBUG, "decode AAAA failed, %s", domain);
 			return -1;
 		}

@@ -1773,12 +1780,12 @@ static int _dns_decode_an(struct dns_context *context, dns_rr_type type)
 		unsigned char *opt_start = context->ptr;
 		ret = _dns_decode_opt(context, type, ttl, rr_len);
 		if (ret < 0) {
-			tlog(TLOG_ERROR, "decode opt failed, %s", domain);
+			tlog(TLOG_DEBUG, "decode opt failed, %s", domain);
 			return -1;
 		}

 		if (context->ptr - opt_start != rr_len) {
-			tlog(TLOG_ERROR, "opt length mismatch, %s\n", domain);
+			tlog(TLOG_DEBUG, "opt length mismatch, %s\n", domain);
 			return -1;
 		}

@@ -1786,14 +1793,14 @@ static int _dns_decode_an(struct dns_context *context, dns_rr_type type)
 	} break;
 	default: {
 		unsigned char raw_data[1024];
-		if (_dns_left_len(context) < rr_len || rr_len >= sizeof(raw_data)) {
+		if (_dns_left_len(context) < rr_len || rr_len >= (int)sizeof(raw_data)) {
 			tlog(TLOG_DEBUG, "length mismatch\n");
 			return -1;
 		}

 		ret = _dns_decode_raw(context, raw_data, rr_len);
 		if (ret < 0) {
-			tlog(TLOG_ERROR, "decode A failed, %s", domain);
+			tlog(TLOG_DEBUG, "decode A failed, %s", domain);
 			return -1;
 		}

@@ -1802,7 +1809,7 @@ static int _dns_decode_an(struct dns_context *context, dns_rr_type type)
 			tlog(TLOG_ERROR, "add raw failed, %s", domain);
 			return -1;
 		}
-		
+
 		tlog(TLOG_DEBUG, "DNS type = %d not supported", qtype);
 		break;
 	}
@@ -1818,7 +1825,7 @@ static int _dns_decode_an(struct dns_context *context, dns_rr_type type)

 static int _dns_encode_qd(struct dns_context *context, struct dns_rrs *rrs)
 {
-	int ret;
+	int ret = 0;
 	int qtype = 0;
 	int qclass = 0;
 	char domain[DNS_MAX_CNAME_LEN];
@@ -1840,7 +1847,7 @@ static int _dns_encode_qd(struct dns_context *context, struct dns_rrs *rrs)

 static int _dns_encode_an(struct dns_context *context, struct dns_rrs *rrs)
 {
-	int ret;
+	int ret = 0;
 	switch (rrs->type) {
 	case DNS_T_A:
 	case DNS_T_AAAA: {
@@ -1930,8 +1937,8 @@ static int _dns_encode_body(struct dns_context *context)
 	struct dns_head *head = &packet->head;
 	int i = 0;
 	int len = 0;
-	struct dns_rrs *rrs;
-	int count;
+	struct dns_rrs *rrs = NULL;
+	int count = 0;

 	rrs = dns_get_rrs_start(packet, DNS_RRS_QD, &count);
 	head->qdcount = count;
@@ -1984,7 +1991,7 @@ static int _dns_encode_body(struct dns_context *context)
 int dns_packet_init(struct dns_packet *packet, int size, struct dns_head *head)
 {
 	struct dns_head *init_head = &packet->head;
-	if (size < sizeof(*packet)) {
+	if (size < (int)sizeof(*packet)) {
 		return -1;
 	}

@@ -2079,13 +2086,13 @@ int dns_encode(unsigned char *data, int size, struct dns_packet *packet)

 static int _dns_update_an(struct dns_context *context, dns_rr_type type, struct dns_update_param *param)
 {
-	int ret;
+	int ret = 0;
 	int qtype = 0;
 	int qclass = 0;
-	int ttl;
+	int ttl = 0;
 	int rr_len = 0;
 	char domain[DNS_MAX_CNAME_LEN];
-	unsigned char *start;
+	unsigned char *start = NULL;

 	/* decode rr head */
 	ret = _dns_decode_rr_head(context, domain, DNS_MAX_CNAME_LEN, &qtype, &qclass, &ttl, &rr_len);
@@ -2115,7 +2122,6 @@ static int _dns_update_an(struct dns_context *context, dns_rr_type type, struct
 	return 0;
 }

-
 static int _dns_update_body(struct dns_context *context, struct dns_update_param *param)
 {
 	struct dns_packet *packet = context->packet;
@@ -2128,9 +2134,9 @@ static int _dns_update_body(struct dns_context *context, struct dns_update_param
 	head->qdcount = 0;
 	for (i = 0; i < count; i++) {
 		char domain[DNS_MAX_CNAME_LEN];
-		int qtype;
-		int qclass;
-		int len;
+		int qtype = 0;
+		int qclass = 0;
+		int len = 0;
 		len = _dns_decode_qr_head(context, domain, DNS_MAX_CNAME_LEN, &qtype, &qclass);
 		if (len < 0) {
 			tlog(TLOG_DEBUG, "update qd failed.");
@@ -2171,8 +2177,8 @@ static int _dns_update_body(struct dns_context *context, struct dns_update_param
 	return 0;
 }

-int _dns_update_id(unsigned char *data, int size, struct dns_update_param *param) {
-
+static int _dns_update_id(unsigned char *data, int size, struct dns_update_param *param)
+{
 	unsigned char *ptr = data;
 	_dns_write_short(&ptr, param->id);
 	return 0;
@@ -2213,47 +2219,7 @@ int dns_packet_update(unsigned char *data, int size, struct dns_update_param *pa
 	if (ret < 0) {
 		tlog(TLOG_DEBUG, "decode body failed.\n");
 		return -1;
-	}	
+	}

 	return 0;
 }
-
-#if 0
-void dns_debug(void)
-{
-	unsigned char data[1024];
-	int len;
-	char buff[4096];
-
-	int fd = open("dns.bin", O_RDWR);
-	if (fd < 0) {
-		return;
-	}
-	len = read(fd, data, 1024);
-	close(fd);
-	if (len < 0) {
-		return;
-	}
-
-	struct dns_packet *packet = (struct dns_packet *)buff;
-	if (dns_decode(packet, 4096, data, len) != 0) {
-		tlog(TLOG_ERROR, "decode failed.\n");
-	}
-
-	memset(data, 0, sizeof(data));
-	len = dns_encode(data, 1024, packet);
-	if (len < 0) {
-		tlog(TLOG_ERROR, "encode failed.");
-	}
-
-	fd = open("dns-cmp.bin", O_CREAT | O_TRUNC | O_RDWR, 0660);
-	write(fd, data, len);
-	close(fd);
-
-	packet = (struct dns_packet *)buff;
-	if (dns_decode(packet, 4096, data, len) != 0) {
-		tlog(TLOG_ERROR, "decode failed.\n");
-	}
-
-}
-#endif
--- a/src/dns.h
+++ b/src/dns.h
@@ -23,8 +23,8 @@
 #define DNS_RR_AAAA_LEN 16
 #define DNS_MAX_CNAME_LEN 256
 #define DNS_MAX_OPT_LEN 256
-#define DNS_IN_PACKSIZE (512 * 4)
-#define DNS_PACKSIZE (512 * 10)
+#define DNS_IN_PACKSIZE (512 * 8)
+#define DNS_PACKSIZE (512 * 12)
 #define DNS_DEFAULT_PACKET_SIZE 512

 #define DNS_ADDR_FAMILY_IP 1
@@ -121,7 +121,7 @@ struct dns_head {

 #define DNS_PACKET_DICT_SIZE 16
 struct dns_packet_dict_item {
-	unsigned pos;
+	unsigned short pos;
 	unsigned int hash;
 };

@@ -150,7 +150,7 @@ struct dns_rrs {
 	struct dns_packet *packet;
 	unsigned short next;
 	unsigned short len;
-	dns_type_t type;
+	int type;
 	unsigned char data[0];
 };

@@ -159,7 +159,7 @@ struct dns_context {
 	struct dns_packet *packet;
 	struct dns_packet_dict *namedict;
 	unsigned char *data;
-	unsigned int maxsize;
+	int maxsize;
 	unsigned char *ptr;
 };

@@ -205,29 +205,29 @@ struct dns_rrs *dns_get_rrs_start(struct dns_packet *packet, dns_rr_type type, i
 /*
 * Question
 */
-int dns_add_domain(struct dns_packet *packet, char *domain, int qtype, int qclass);
+int dns_add_domain(struct dns_packet *packet, const char *domain, int qtype, int qclass);
 int dns_get_domain(struct dns_rrs *rrs, char *domain, int maxsize, int *qtype, int *qclass);

 /*
 * Answers
 */
-int dns_add_CNAME(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, char *cname);
+int dns_add_CNAME(struct dns_packet *packet, dns_rr_type type, const char *domain, int ttl, const char *cname);
 int dns_get_CNAME(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, char *cname, int cname_size);

-int dns_add_A(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, unsigned char addr[DNS_RR_A_LEN]);
+int dns_add_A(struct dns_packet *packet, dns_rr_type type, const char *domain, int ttl, unsigned char addr[DNS_RR_A_LEN]);
 int dns_get_A(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, unsigned char addr[DNS_RR_A_LEN]);

-int dns_add_PTR(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, char *cname);
+int dns_add_PTR(struct dns_packet *packet, dns_rr_type type, const char *domain, int ttl, char *cname);
 int dns_get_PTR(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, char *cname, int cname_size);

-int dns_add_AAAA(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl,
+int dns_add_AAAA(struct dns_packet *packet, dns_rr_type type, const char *domain, int ttl,
 				 unsigned char addr[DNS_RR_AAAA_LEN]);
 int dns_get_AAAA(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, unsigned char addr[DNS_RR_AAAA_LEN]);

-int dns_add_SOA(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, struct dns_soa *soa);
+int dns_add_SOA(struct dns_packet *packet, dns_rr_type type, const char *domain, int ttl, struct dns_soa *soa);
 int dns_get_SOA(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, struct dns_soa *soa);

-int dns_add_NS(struct dns_packet *packet, dns_rr_type type, char *domain, int ttl, char *cname);
+int dns_add_NS(struct dns_packet *packet, dns_rr_type type, const char *domain, int ttl, const char *cname);
 int dns_get_NS(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, char *cname, int cname_size);

 int dns_set_OPT_payload_size(struct dns_packet *packet, int payload_size);
--- a/src/dns_cache.c
+++ b/src/dns_cache.c
@@ -243,8 +243,8 @@ struct dns_cache_data *dns_cache_new_data_packet(uint32_t cache_flag, void *pack
 	return (struct dns_cache_data *)cache_packet;
 }

-int _dns_cache_replace(char *domain, int ttl, dns_type_t qtype, int speed, int inactive,
-					   struct dns_cache_data *cache_data)
+static int _dns_cache_replace(char *domain, int ttl, dns_type_t qtype, int speed, int inactive,
+							  struct dns_cache_data *cache_data)
 {
 	struct dns_cache *dns_cache = NULL;
 	struct dns_cache_data *old_cache_data = NULL;
@@ -300,18 +300,38 @@ int dns_cache_replace_inactive(char *domain, int ttl, dns_type_t qtype, int spee
 	return _dns_cache_replace(domain, ttl, qtype, speed, 1, cache_data);
 }

-int _dns_cache_insert(struct dns_cache_info *info, struct dns_cache_data *cache_data, struct list_head *head)
+static void _dns_cache_remove_by_domain(const char *domain, dns_type_t qtype)
+{
+	uint32_t key = 0;
+	struct dns_cache *dns_cache = NULL;
+
+	key = hash_string(domain);
+	key = jhash(&qtype, sizeof(qtype), key);
+	pthread_mutex_lock(&dns_cache_head.lock);
+	hash_for_each_possible(dns_cache_head.cache_hash, dns_cache, node, key)
+	{
+		if (dns_cache->info.qtype != qtype) {
+			continue;
+		}
+
+		if (strncmp(domain, dns_cache->info.domain, DNS_MAX_CNAME_LEN) != 0) {
+			continue;
+		}
+
+		_dns_cache_remove(dns_cache);
+		break;
+	}
+
+	pthread_mutex_unlock(&dns_cache_head.lock);
+}
+
+static 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 cache already exists, free */
-	dns_cache = dns_cache_lookup(info->domain, info->qtype);
-	if (dns_cache) {
-		dns_cache_delete(dns_cache);
-		dns_cache_release(dns_cache);
-		dns_cache = NULL;
-	}
+	_dns_cache_remove_by_domain(info->domain, info->qtype);

 	dns_cache = malloc(sizeof(*dns_cache));
 	if (dns_cache == NULL) {
@@ -332,7 +352,7 @@ int _dns_cache_insert(struct dns_cache_info *info, struct dns_cache_data *cache_

 	/* Release extra cache, remove oldest cache record */
 	if (atomic_inc_return(&dns_cache_head.num) > dns_cache_head.size) {
-		struct dns_cache *del_cache;
+		struct dns_cache *del_cache = NULL;
 		del_cache = _dns_inactive_cache_first();
 		if (del_cache) {
 			_dns_cache_remove(del_cache);
@@ -383,7 +403,7 @@ struct dns_cache *dns_cache_lookup(char *domain, dns_type_t qtype)
 	uint32_t key = 0;
 	struct dns_cache *dns_cache = NULL;
 	struct dns_cache *dns_cache_ret = NULL;
-	time_t now;
+	time_t now = 0;

 	if (dns_cache_head.size <= 0) {
 		return NULL;
@@ -426,7 +446,7 @@ struct dns_cache *dns_cache_lookup(char *domain, dns_type_t qtype)

 int dns_cache_get_ttl(struct dns_cache *dns_cache)
 {
-	time_t now;
+	time_t now = 0;
 	int ttl = 0;
 	time(&now);

@@ -440,7 +460,7 @@ int dns_cache_get_ttl(struct dns_cache *dns_cache)

 int dns_cache_get_cname_ttl(struct dns_cache *dns_cache)
 {
-	time_t now;
+	time_t now = 0;
 	int ttl = 0;
 	time(&now);

@@ -522,12 +542,12 @@ void dns_cache_update(struct dns_cache *dns_cache)
 	pthread_mutex_unlock(&dns_cache_head.lock);
 }

-void _dns_cache_remove_expired_ttl(dns_cache_callback inactive_precallback, int ttl_inactive_pre,
-								   unsigned int max_callback_num, time_t *now)
+static void _dns_cache_remove_expired_ttl(dns_cache_callback inactive_precallback, int ttl_inactive_pre,
+										  unsigned int max_callback_num, const time_t *now)
 {
 	struct dns_cache *dns_cache = NULL;
-	struct dns_cache *tmp;
-	int callback_num = 0;
+	struct dns_cache *tmp = NULL;
+	unsigned int callback_num = 0;
 	int ttl = 0;
 	LIST_HEAD(checklist);

@@ -579,11 +599,11 @@ void dns_cache_invalidate(dns_cache_callback precallback, int ttl_pre, unsigned
 						  dns_cache_callback inactive_precallback, int ttl_inactive_pre)
 {
 	struct dns_cache *dns_cache = NULL;
-	struct dns_cache *tmp;
-	time_t now;
+	struct dns_cache *tmp = NULL;
+	time_t now = 0;
 	int ttl = 0;
 	LIST_HEAD(checklist);
-	int callback_num = 0;
+	unsigned int callback_num = 0;

 	if (max_callback_num <= 0) {
 		max_callback_num = -1;
@@ -637,8 +657,8 @@ void dns_cache_invalidate(dns_cache_callback precallback, int ttl_pre, unsigned
 static int _dns_cache_read_record(int fd, uint32_t cache_number)
 {

-	int i = 0;
-	int ret = 0;
+	unsigned int i = 0;
+	ssize_t ret = 0;
 	struct dns_cache_record cache_record;
 	struct dns_cache_data_head data_head;
 	struct dns_cache_data *cache_data = NULL;
@@ -706,8 +726,9 @@ errout:
 int dns_cache_load(const char *file)
 {
 	int fd = -1;
-	int ret = 0;
-	size_t filesize;
+	ssize_t ret = 0;
+	off_t filesize = 0;
+
 	fd = open(file, O_RDONLY);
 	if (fd < 0) {
 		return 0;
@@ -729,7 +750,7 @@ int dns_cache_load(const char *file)
 		goto errout;
 	}

-	if (strncmp(cache_file.version, __TIMESTAMP__, DNS_CACHE_VERSION_LEN) != 0) {
+	if (strncmp(cache_file.version, __TIMESTAMP__, DNS_CACHE_VERSION_LEN - 1) != 0) {
 		tlog(TLOG_WARN, "cache version is different, skip load cache.");
 		goto errout;
 	}
@@ -761,7 +782,7 @@ static int _dns_cache_write_record(int fd, uint32_t *cache_number, enum CACHE_RE
 		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));
+		ssize_t ret = write(fd, &cache_record, sizeof(cache_record));
 		if (ret != sizeof(cache_record)) {
 			tlog(TLOG_ERROR, "write cache failed, %s", strerror(errno));
 			goto errout;
@@ -769,7 +790,7 @@ static int _dns_cache_write_record(int fd, uint32_t *cache_number, enum CACHE_RE

 		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) {
+		if (ret != (int)sizeof(*cache_data) + cache_data->head.size) {
 			tlog(TLOG_ERROR, "write cache data failed, %s", strerror(errno));
 			goto errout;
 		}
@@ -853,7 +874,8 @@ errout:
 void dns_cache_destroy(void)
 {
 	struct dns_cache *dns_cache = NULL;
-	struct dns_cache *tmp;
+	struct dns_cache *tmp = NULL;
+
 	pthread_mutex_lock(&dns_cache_head.lock);
 	list_for_each_entry_safe(dns_cache, tmp, &dns_cache_head.inactive_list, list)
 	{
--- a/src/dns_cache.h
+++ b/src/dns_cache.h
@@ -31,7 +31,7 @@
 extern "C" {
 #endif

-#define DNS_CACHE_TTL_MIN 30
+#define DNS_CACHE_TTL_MIN 1
 #define DNS_CACHE_VERSION_LEN 32
 #define MAGIC_NUMBER 0x6548634163536e44
 #define MAGIC_CACHE_DATA 0x44615461
@@ -51,7 +51,7 @@ struct dns_cache_data_head {
 	uint32_t cache_flag;
 	enum CACHE_TYPE cache_type;
 	int is_soa;
-	size_t size;
+	ssize_t size;
 };

 struct dns_cache_data {
--- a/src/dns_client.c
+++ b/src/dns_client.c
@@ -72,7 +72,7 @@ struct dns_client_ecs {
 /* TCP/TLS buffer */
 struct dns_server_buff {
 	unsigned char data[DNS_TCP_BUFFER];
-	unsigned short len;
+	int len;
 };

 typedef enum dns_server_status {
@@ -133,6 +133,7 @@ struct dns_server_pending_group {

 struct dns_server_pending {
 	struct list_head list;
+	struct list_head retry_list;
 	atomic_t refcnt;

 	char host[DNS_HOSTNAME_LEN];
@@ -171,7 +172,7 @@ struct dns_server_group {
 /* dns client */
 struct dns_client {
 	pthread_t tid;
-	int run;
+	atomic_t run;
 	int epoll_fd;

 	/* dns server list */
@@ -251,9 +252,9 @@ 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)
+static ssize_t _ssl_read(struct dns_server_info *server, void *buff, int num)
 {
-	int ret = 0;
+	ssize_t ret = 0;
 	if (server == NULL || buff == NULL) {
 		return SSL_ERROR_SYSCALL;
 	}
@@ -263,9 +264,9 @@ int _ssl_read(struct dns_server_info *server, void *buff, int num)
 	return ret;
 }

-int _ssl_write(struct dns_server_info *server, const void *buff, int num)
+static ssize_t _ssl_write(struct dns_server_info *server, const void *buff, int num)
 {
-	int ret = 0;
+	ssize_t ret = 0;
 	if (server == NULL || buff == NULL || server->ssl == NULL) {
 		return SSL_ERROR_SYSCALL;
 	}
@@ -276,7 +277,7 @@ int _ssl_write(struct dns_server_info *server, const void *buff, int num)
 	return ret;
 }

-int _ssl_shutdown(struct dns_server_info *server)
+static int _ssl_shutdown(struct dns_server_info *server)
 {
 	int ret = 0;
 	if (server == NULL || server->ssl == NULL) {
@@ -289,7 +290,7 @@ int _ssl_shutdown(struct dns_server_info *server)
 	return ret;
 }

-int _ssl_get_error(struct dns_server_info *server, int ret)
+static int _ssl_get_error(struct dns_server_info *server, int ret)
 {
 	int err = 0;
 	if (server == NULL || server->ssl == NULL) {
@@ -302,7 +303,7 @@ int _ssl_get_error(struct dns_server_info *server, int ret)
 	return err;
 }

-int _ssl_do_handshake(struct dns_server_info *server)
+static int _ssl_do_handshake(struct dns_server_info *server)
 {
 	int err = 0;
 	if (server == NULL || server->ssl == NULL) {
@@ -315,7 +316,7 @@ int _ssl_do_handshake(struct dns_server_info *server)
 	return err;
 }

-int _ssl_session_reused(struct dns_server_info *server)
+static int _ssl_session_reused(struct dns_server_info *server)
 {
 	int err = 0;
 	if (server == NULL || server->ssl == NULL) {
@@ -328,9 +329,9 @@ int _ssl_session_reused(struct dns_server_info *server)
 	return err;
 }

-SSL_SESSION *_ssl_get1_session(struct dns_server_info *server)
+static SSL_SESSION *_ssl_get1_session(struct dns_server_info *server)
 {
-	SSL_SESSION *ret = 0;
+	SSL_SESSION *ret = NULL;
 	if (server == NULL || server->ssl == NULL) {
 		return NULL;
 	}
@@ -377,7 +378,7 @@ dns_server_type_t dns_client_get_server_type(struct dns_server_info *server_info
 	return server_info->type;
 }

-const char *_dns_server_get_type_string(dns_server_type_t type)
+static const char *_dns_server_get_type_string(dns_server_type_t type)
 {
 	const char *type_str = "";

@@ -431,7 +432,8 @@ errout:
 /* check whether server exists */
 static int _dns_client_server_exist(const char *server_ip, int port, dns_server_type_t server_type)
 {
-	struct dns_server_info *server_info, *tmp;
+	struct dns_server_info *server_info = NULL;
+	struct dns_server_info *tmp = NULL;
 	pthread_mutex_lock(&client.server_list_lock);
 	list_for_each_entry_safe(server_info, tmp, &client.dns_server_list, list)
 	{
@@ -439,7 +441,7 @@ static int _dns_client_server_exist(const char *server_ip, int port, dns_server_
 			continue;
 		}

-		if (strncmp(server_info->ip, server_ip, DNS_HOSTNAME_LEN)) {
+		if (strncmp(server_info->ip, server_ip, DNS_HOSTNAME_LEN) != 0) {
 			continue;
 		}

@@ -468,7 +470,8 @@ static void _dns_client_server_update_ttl(struct ping_host_struct *ping_host, co
 /* get server control block by ip and port, type */
 static struct dns_server_info *_dns_client_get_server(char *server_ip, int port, dns_server_type_t server_type)
 {
-	struct dns_server_info *server_info, *tmp;
+	struct dns_server_info *server_info = NULL;
+	struct dns_server_info *tmp = NULL;
 	struct dns_server_info *server_info_return = NULL;

 	if (server_ip == NULL) {
@@ -482,7 +485,7 @@ static struct dns_server_info *_dns_client_get_server(char *server_ip, int port,
 			continue;
 		}

-		if (strncmp(server_info->ip, server_ip, DNS_HOSTNAME_LEN)) {
+		if (strncmp(server_info->ip, server_ip, DNS_HOSTNAME_LEN) != 0) {
 			continue;
 		}

@@ -499,7 +502,7 @@ static struct dns_server_info *_dns_client_get_server(char *server_ip, int port,
 /* get server group by name */
 static struct dns_server_group *_dns_client_get_group(const char *group_name)
 {
-	unsigned long key;
+	uint32_t key = 0;
 	struct dns_server_group *group = NULL;
 	struct hlist_node *tmp = NULL;

@@ -541,7 +544,7 @@ static struct dns_server_group *_dns_client_get_dnsserver_group(const char *grou
 }

 /* add server to group */
-static int _dns_client_add_to_group(char *group_name, struct dns_server_info *server_info)
+static int _dns_client_add_to_group(const char *group_name, struct dns_server_info *server_info)
 {
 	struct dns_server_group *group = NULL;
 	struct dns_server_group_member *group_member = NULL;
@@ -571,9 +574,11 @@ errout:
 	return -1;
 }

-static int _dns_client_add_to_pending_group(char *group_name, char *server_ip, int port, dns_server_type_t server_type)
+static int _dns_client_add_to_pending_group(const char *group_name, char *server_ip, int port,
+											dns_server_type_t server_type)
 {
-	struct dns_server_pending *item, *tmp;
+	struct dns_server_pending *item = NULL;
+	struct dns_server_pending *tmp = NULL;
 	struct dns_server_pending *pending = NULL;
 	struct dns_server_pending_group *group = NULL;

@@ -617,8 +622,8 @@ errout:
 }

 /* add server to group */
-static int _dns_client_add_to_group_pending(char *group_name, char *server_ip, int port, dns_server_type_t server_type,
-											int ispending)
+static int _dns_client_add_to_group_pending(const char *group_name, char *server_ip, int port,
+											dns_server_type_t server_type, int ispending)
 {
 	struct dns_server_info *server_info = NULL;

@@ -638,7 +643,7 @@ static int _dns_client_add_to_group_pending(char *group_name, char *server_ip, i
 	return _dns_client_add_to_group(group_name, server_info);
 }

-int dns_client_add_to_group(char *group_name, char *server_ip, int port, dns_server_type_t server_type)
+int dns_client_add_to_group(const char *group_name, char *server_ip, int port, dns_server_type_t server_type)
 {
 	return _dns_client_add_to_group_pending(group_name, server_ip, port, server_type, 1);
 }
@@ -654,8 +659,8 @@ static int _dns_client_remove_member(struct dns_server_group_member *group_membe

 static int _dns_client_remove_from_group(struct dns_server_group *group, struct dns_server_info *server_info)
 {
-	struct dns_server_group_member *group_member;
-	struct dns_server_group_member *tmp;
+	struct dns_server_group_member *group_member = NULL;
+	struct dns_server_group_member *tmp = NULL;

 	list_for_each_entry_safe(group_member, tmp, &group->head, list)
 	{
@@ -671,9 +676,9 @@ static int _dns_client_remove_from_group(struct dns_server_group *group, struct

 static int _dns_client_remove_server_from_groups(struct dns_server_info *server_info)
 {
-	struct dns_server_group *group;
+	struct dns_server_group *group = NULL;
 	struct hlist_node *tmp = NULL;
-	int i = 0;
+	unsigned long i = 0;

 	hash_for_each_safe(client.group, i, tmp, group, node)
 	{
@@ -683,7 +688,7 @@ static int _dns_client_remove_server_from_groups(struct dns_server_info *server_
 	return 0;
 }

-int dns_client_remove_from_group(char *group_name, char *server_ip, int port, dns_server_type_t server_type)
+int dns_client_remove_from_group(const char *group_name, char *server_ip, int port, dns_server_type_t server_type)
 {
 	struct dns_server_info *server_info = NULL;
 	struct dns_server_group *group = NULL;
@@ -701,9 +706,9 @@ int dns_client_remove_from_group(char *group_name, char *server_ip, int port, dn
 	return _dns_client_remove_from_group(group, server_info);
 }

-int dns_client_add_group(char *group_name)
+int dns_client_add_group(const char *group_name)
 {
-	unsigned long key;
+	uint32_t key = 0;
 	struct dns_server_group *group = NULL;

 	if (group_name == NULL) {
@@ -738,8 +743,8 @@ errout:

 static int _dns_client_remove_group(struct dns_server_group *group)
 {
-	struct dns_server_group_member *group_member;
-	struct dns_server_group_member *tmp;
+	struct dns_server_group_member *group_member = NULL;
+	struct dns_server_group_member *tmp = NULL;

 	if (group == NULL) {
 		return 0;
@@ -756,9 +761,9 @@ static int _dns_client_remove_group(struct dns_server_group *group)
 	return 0;
 }

-int dns_client_remove_group(char *group_name)
+int dns_client_remove_group(const char *group_name)
 {
-	unsigned long key;
+	uint32_t key = 0;
 	struct dns_server_group *group = NULL;
 	struct hlist_node *tmp = NULL;

@@ -783,9 +788,9 @@ int dns_client_remove_group(char *group_name)

 static void _dns_client_group_remove_all(void)
 {
-	struct dns_server_group *group;
+	struct dns_server_group *group = NULL;
 	struct hlist_node *tmp = NULL;
-	int i = 0;
+	unsigned long i = 0;

 	hash_for_each_safe(client.group, i, tmp, group, node)
 	{
@@ -909,7 +914,7 @@ static int _dns_client_set_trusted_cert(SSL_CTX *ssl_ctx)
 	return 0;
 }

-SSL_CTX *_ssl_ctx_get(void)
+static SSL_CTX *_ssl_ctx_get(void)
 {
 	pthread_mutex_lock(&client.server_list_lock);
 	SSL_CTX *ssl_ctx = client.ssl_ctx;
@@ -959,7 +964,7 @@ static int _dns_client_server_add(char *server_ip, char *server_host, int port,
 	int spki_data_len = 0;
 	int ttl = 0;
 	char port_s[8];
-	int sock_type;
+	int sock_type = 0;
 	char skip_check_cert = 0;

 	switch (server_type) {
@@ -1195,7 +1200,8 @@ static void _dns_client_server_close(struct dns_server_info *server_info)
 /* remove all servers information */
 static void _dns_client_server_remove_all(void)
 {
-	struct dns_server_info *server_info, *tmp;
+	struct dns_server_info *server_info = NULL;
+	struct dns_server_info *tmp = NULL;
 	pthread_mutex_lock(&client.server_list_lock);
 	list_for_each_entry_safe(server_info, tmp, &client.dns_server_list, list)
 	{
@@ -1210,7 +1216,8 @@ static void _dns_client_server_remove_all(void)
 /* remove single server */
 static int _dns_client_server_remove(char *server_ip, int port, dns_server_type_t server_type)
 {
-	struct dns_server_info *server_info, *tmp;
+	struct dns_server_info *server_info = NULL;
+	struct dns_server_info *tmp = NULL;

 	/* find server and remove */
 	pthread_mutex_lock(&client.server_list_lock);
@@ -1220,7 +1227,7 @@ static int _dns_client_server_remove(char *server_ip, int port, dns_server_type_
 			continue;
 		}

-		if (strncmp(server_info->ip, server_ip, DNS_HOSTNAME_LEN)) {
+		if (strncmp(server_info->ip, server_ip, DNS_HOSTNAME_LEN) != 0) {
 			continue;
 		}

@@ -1236,28 +1243,28 @@ static int _dns_client_server_remove(char *server_ip, int port, dns_server_type_
 	return -1;
 }

-void _dns_client_server_pending_get(struct dns_server_pending *pending)
+static void _dns_client_server_pending_get(struct dns_server_pending *pending)
 {
 	if (atomic_inc_return(&pending->refcnt) <= 0) {
-		tlog(TLOG_ERROR, "BUG: pending ref is invalid");
-		abort();
+		BUG("pending ref is invalid");
 	}
 }

-void _dns_client_server_pending_release_lck(struct dns_server_pending *pending)
+static void _dns_client_server_pending_release(struct dns_server_pending *pending)
 {
-	struct dns_server_pending_group *group, *tmp;
+	struct dns_server_pending_group *group = NULL;
+	struct dns_server_pending_group *tmp = NULL;

 	int refcnt = atomic_dec_return(&pending->refcnt);

 	if (refcnt) {
 		if (refcnt < 0) {
-			tlog(TLOG_ERROR, "BUG: pending refcnt is %d", refcnt);
-			abort();
+			BUG("BUG: pending refcnt is %d", refcnt);
 		}
 		return;
 	}

+	pthread_mutex_lock(&pending_server_mutex);
 	list_for_each_entry_safe(group, tmp, &pending->group_list, list)
 	{
 		list_del_init(&group->list);
@@ -1265,26 +1272,16 @@ void _dns_client_server_pending_release_lck(struct dns_server_pending *pending)
 	}

 	list_del_init(&pending->list);
+	pthread_mutex_unlock(&pending_server_mutex);
 	free(pending);
 }

-void _dns_client_server_pending_release(struct dns_server_pending *pending)
+static void _dns_client_server_pending_remove(struct dns_server_pending *pending)
 {
-	int refcnt = atomic_dec_return(&pending->refcnt);
-
-	if (refcnt) {
-		if (refcnt < 0) {
-			tlog(TLOG_ERROR, "BUG: pending refcnt is %d", refcnt);
-			abort();
-		}
-		return;
-	}
-
 	pthread_mutex_lock(&pending_server_mutex);
 	list_del_init(&pending->list);
 	pthread_mutex_unlock(&pending_server_mutex);
-
-	free(pending);
+	_dns_client_server_pending_release(pending);
 }

 static int _dns_client_server_pending(char *server_ip, int port, dns_server_type_t server_type,
@@ -1310,6 +1307,7 @@ static int _dns_client_server_pending(char *server_ip, int port, dns_server_type
 	pending->has_v6 = 0;
 	_dns_client_server_pending_get(pending);
 	INIT_LIST_HEAD(&pending->group_list);
+	INIT_LIST_HEAD(&pending->retry_list);
 	memcpy(&pending->flags, flags, sizeof(struct client_dns_server_flags));

 	pthread_mutex_lock(&pending_server_mutex);
@@ -1327,7 +1325,7 @@ errout:
 static int _dns_client_add_server_pending(char *server_ip, char *server_host, int port, dns_server_type_t server_type,
 										  struct client_dns_server_flags *flags, int ispending)
 {
-	int ret;
+	int ret = 0;

 	if (server_type >= DNS_SERVER_TYPE_END) {
 		tlog(TLOG_ERROR, "server type is invalid.");
@@ -1374,22 +1372,20 @@ int dns_server_num(void)
 static void _dns_client_query_get(struct dns_query_struct *query)
 {
 	if (atomic_inc_return(&query->refcnt) <= 0) {
-		tlog(TLOG_ERROR, "BUG: query ref is invalid, domain: %s", query->domain);
-		abort();
+		BUG("query ref is invalid, domain: %s", query->domain);
 	}
 }

 static void _dns_client_query_release(struct dns_query_struct *query)
 {
 	int refcnt = atomic_dec_return(&query->refcnt);
-	int bucket = 0;
-	struct dns_query_replied *replied_map;
-	struct hlist_node *tmp;
+	unsigned long bucket = 0;
+	struct dns_query_replied *replied_map = NULL;
+	struct hlist_node *tmp = NULL;

 	if (refcnt) {
 		if (refcnt < 0) {
-			tlog(TLOG_ERROR, "BUG: refcnt is %d", refcnt);
-			abort();
+			BUG("BUG: refcnt is %d", refcnt);
 		}
 		return;
 	}
@@ -1398,7 +1394,7 @@ static void _dns_client_query_release(struct dns_query_struct *query)
 	if (query->callback) {
 		tlog(TLOG_DEBUG, "result: %s, qtype: %d, hasresult: %d, id %d", query->domain, query->qtype, query->has_result,
 			 query->sid);
-		query->callback(query->domain, DNS_QUERY_END, 0, NULL, NULL, 0, query->user_ptr);
+		query->callback(query->domain, DNS_QUERY_END, NULL, NULL, NULL, 0, query->user_ptr);
 	}

 	/* free resource */
@@ -1433,7 +1429,8 @@ static void _dns_client_query_remove(struct dns_query_struct *query)

 static void _dns_client_query_remove_all(void)
 {
-	struct dns_query_struct *query, *tmp;
+	struct dns_query_struct *query = NULL;
+	struct dns_query_struct *tmp = NULL;
 	LIST_HEAD(check_list);

 	pthread_mutex_lock(&client.domain_map_lock);
@@ -1448,8 +1445,6 @@ static void _dns_client_query_remove_all(void)
 		list_del_init(&query->period_list);
 		_dns_client_query_remove(query);
 	}
-
-	return;
 }

 static void _dns_client_check_udp_nat(struct dns_query_struct *query)
@@ -1482,8 +1477,8 @@ static void _dns_client_check_udp_nat(struct dns_query_struct *query)

 static void _dns_client_check_tcp(void)
 {
-	struct dns_server_info *server_info;
-	time_t now;
+	struct dns_server_info *server_info = NULL;
+	time_t now = 0;

 	time(&now);

@@ -1517,7 +1512,7 @@ static struct dns_query_struct *_dns_client_get_request(unsigned short sid, char
 	struct dns_query_struct *query = NULL;
 	struct dns_query_struct *query_result = NULL;
 	struct hlist_node *tmp = NULL;
-	uint32_t key;
+	uint32_t key = 0;

 	/* get query by hash key : id + domain */
 	key = hash_string(domain);
@@ -1577,17 +1572,17 @@ static int _dns_replied_check_add(struct dns_query_struct *dns_query, struct soc
 static int _dns_client_recv(struct dns_server_info *server_info, unsigned char *inpacket, int inpacket_len,
 							struct sockaddr *from, socklen_t from_len)
 {
-	int len;
-	int i;
-	int qtype;
-	int qclass;
+	int len = 0;
+	int i = 0;
+	int qtype = 0;
+	int qclass = 0;
 	char domain[DNS_MAX_CNAME_LEN];
-	int rr_count;
+	int rr_count = 0;
 	struct dns_rrs *rrs = NULL;
 	unsigned char packet_buff[DNS_PACKSIZE];
 	struct dns_packet *packet = (struct dns_packet *)packet_buff;
 	int ret = 0;
-	struct dns_query_struct *query;
+	struct dns_query_struct *query = NULL;
 	int request_num = 0;
 	int has_opt = 0;

@@ -1597,8 +1592,11 @@ static int _dns_client_recv(struct dns_server_info *server_info, unsigned char *
 	len = dns_decode(packet, DNS_PACKSIZE, inpacket, inpacket_len);
 	if (len != 0) {
 		char host_name[DNS_MAX_CNAME_LEN];
-		tlog(TLOG_WARN, "decode failed, packet len = %d, tc = %d, id = %d, from = %s\n", inpacket_len, packet->head.tc,
+		tlog(TLOG_INFO, "decode failed, packet len = %d, tc = %d, id = %d, from = %s\n", inpacket_len, packet->head.tc,
 			 packet->head.id, gethost_by_addr(host_name, sizeof(host_name), from));
+		if (dns_save_fail_packet) {
+			dns_packet_save(dns_save_fail_packet_dir, "client", host_name, inpacket, inpacket_len);
+		}
 		return -1;
 	}

@@ -1638,7 +1636,7 @@ static int _dns_client_recv(struct dns_server_info *server_info, unsigned char *
 	}

 	/* avoid multiple replies */
-	if (_dns_replied_check_add(query, (struct sockaddr *)from, from_len) != 0) {
+	if (_dns_replied_check_add(query, from, from_len) != 0) {
 		_dns_client_query_release(query);
 		return 0;
 	}
@@ -1683,6 +1681,9 @@ static int _dns_client_create_socket_udp(struct dns_server_info *server_info)
 		goto errout;
 	}

+	server_info->fd = fd;
+	server_info->status = DNS_SERVER_STATUS_CONNECTIONLESS;
+
 	memset(&event, 0, sizeof(event));
 	event.events = EPOLLIN;
 	event.data.ptr = server_info;
@@ -1691,8 +1692,6 @@ static int _dns_client_create_socket_udp(struct dns_server_info *server_info)
 		return -1;
 	}

-	server_info->fd = fd;
-	server_info->status = DNS_SERVER_STATUS_CONNECTIONLESS;
 	setsockopt(server_info->fd, IPPROTO_IP, IP_RECVTTL, &on, sizeof(on));
 	setsockopt(server_info->fd, SOL_IP, IP_TTL, &val, sizeof(val));
 	setsockopt(server_info->fd, SOL_SOCKET, SO_PRIORITY, &priority, sizeof(priority));
@@ -1710,6 +1709,9 @@ errout:
 		close(fd);
 	}

+	server_info->fd = -1;
+	server_info->status = DNS_SERVER_STATUS_DISCONNECTED;
+
 	return -1;
 }

@@ -1723,7 +1725,7 @@ static int _DNS_client_create_socket_tcp(struct dns_server_info *server_info)

 	fd = socket(server_info->ai_family, SOCK_STREAM, 0);
 	if (fd < 0) {
-		tlog(TLOG_ERROR, "create socket failed.");
+		tlog(TLOG_ERROR, "create socket failed, %s", strerror(errno));
 		goto errout;
 	}

@@ -1734,7 +1736,7 @@ static int _DNS_client_create_socket_tcp(struct dns_server_info *server_info)

 	/* enable tcp fast open */
 	if (setsockopt(fd, IPPROTO_TCP, TCP_FASTOPEN_CONNECT, &yes, sizeof(yes)) != 0) {
-		tlog(TLOG_DEBUG, "enable TCP fast open failed.");
+		tlog(TLOG_DEBUG, "enable TCP fast open failed, %s", strerror(errno));
 	}

 	setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &yes, sizeof(yes));
@@ -1744,7 +1746,7 @@ static int _DNS_client_create_socket_tcp(struct dns_server_info *server_info)
 	setsockopt(fd, IPPROTO_TCP, TCP_THIN_LINEAR_TIMEOUTS, &yes, sizeof(yes));
 	set_sock_keepalive(fd, 15, 3, 4);

-	if (connect(fd, (struct sockaddr *)&server_info->addr, server_info->ai_addrlen) != 0) {
+	if (connect(fd, &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;
@@ -1826,7 +1828,7 @@ static int _DNS_client_create_socket_tls(struct dns_server_info *server_info, ch
 	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 (connect(fd, &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;
@@ -1906,11 +1908,11 @@ static int _dns_client_create_socket(struct dns_server_info *server_info)
 	} else if (server_info->type == DNS_SERVER_TCP) {
 		return _DNS_client_create_socket_tcp(server_info);
 	} else if (server_info->type == DNS_SERVER_TLS) {
-		struct client_dns_server_flag_tls *flag_tls;
+		struct client_dns_server_flag_tls *flag_tls = NULL;
 		flag_tls = &server_info->flags.tls;
 		return _DNS_client_create_socket_tls(server_info, flag_tls->hostname);
 	} else if (server_info->type == DNS_SERVER_HTTPS) {
-		struct client_dns_server_flag_https *flag_https;
+		struct client_dns_server_flag_https *flag_https = NULL;
 		flag_https = &server_info->flags.https;
 		return _DNS_client_create_socket_tls(server_info, flag_https->hostname);
 	} else {
@@ -1922,7 +1924,7 @@ static int _dns_client_create_socket(struct dns_server_info *server_info)

 static int _dns_client_process_udp(struct dns_server_info *server_info, struct epoll_event *event, unsigned long now)
 {
-	int len;
+	int len = 0;
 	unsigned char inpacket[DNS_IN_PACKSIZE];
 	struct sockaddr_storage from;
 	socklen_t from_len = sizeof(from);
@@ -1931,7 +1933,7 @@ static int _dns_client_process_udp(struct dns_server_info *server_info, struct e
 	struct iovec iov;
 	char ans_data[4096];
 	int ttl = 0;
-	struct cmsghdr *cmsg;
+	struct cmsghdr *cmsg = NULL;

 	memset(&msg, 0, sizeof(msg));
 	iov.iov_base = (char *)inpacket;
@@ -1990,6 +1992,11 @@ static int _dns_client_socket_ssl_send(struct dns_server_info *server, const voi
 		return -1;
 	}

+	if (num < 0) {
+		errno = EINVAL;
+		return -1;
+	}
+
 	ret = _ssl_write(server, buf, num);
 	if (ret > 0) {
 		return ret;
@@ -2037,7 +2044,7 @@ static int _dns_client_socket_ssl_send(struct dns_server_info *server, const voi

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

@@ -2077,7 +2084,7 @@ static int _dns_client_socket_ssl_recv(struct dns_server_info *server, void *buf
 			return 0;
 		}

-		tlog(TLOG_ERROR, "SSL read fail error no: %s(%lx)\n", ERR_reason_error_string(ssl_err), ssl_err);
+		tlog(TLOG_INFO, "SSL read fail error no: %s(%lx), len: %d\n", ERR_reason_error_string(ssl_err), ssl_err, num);
 		errno = EFAULT;
 		ret = -1;
 		break;
@@ -2211,8 +2218,7 @@ static int _dns_client_process_tcp_buff(struct dns_server_info *server_info)

 		server_info->recv_buff.len -= len;
 		if (server_info->recv_buff.len < 0) {
-			tlog(TLOG_ERROR, "Internal error.");
-			abort();
+			BUG("Internal error.");
 		}

 		/* move to next result */
@@ -2234,7 +2240,7 @@ out:

 static int _dns_client_process_tcp(struct dns_server_info *server_info, struct epoll_event *event, unsigned long now)
 {
-	int len;
+	int len = 0;
 	int ret = -1;

 	if (event->events & EPOLLIN) {
@@ -2289,8 +2295,6 @@ static int _dns_client_process_tcp(struct dns_server_info *server_info, struct e

 	/* when connected */
 	if (event->events & EPOLLOUT) {
-		struct epoll_event event;
-
 		if (server_info->status == DNS_SERVER_STATUS_CONNECTING) {
 			server_info->status = DNS_SERVER_STATUS_CONNECTED;
 			tlog(TLOG_DEBUG, "tcp server %s connected", server_info->ip);
@@ -2315,8 +2319,7 @@ static int _dns_client_process_tcp(struct dns_server_info *server_info, struct e
 			if (server_info->send_buff.len > 0) {
 				memmove(server_info->send_buff.data, server_info->send_buff.data + len, server_info->send_buff.len);
 			} else if (server_info->send_buff.len < 0) {
-				tlog(TLOG_ERROR, "Internal Error");
-				abort();
+				BUG("Internal Error");
 			}
 			pthread_mutex_unlock(&client.server_list_lock);
 		}
@@ -2326,10 +2329,11 @@ static int _dns_client_process_tcp(struct dns_server_info *server_info, struct e
 		}

 		/* clear epllout event */
-		memset(&event, 0, sizeof(event));
-		event.events = EPOLLIN;
-		event.data.ptr = server_info;
-		if (epoll_ctl(client.epoll_fd, EPOLL_CTL_MOD, server_info->fd, &event) != 0) {
+		struct epoll_event mod_event;
+		memset(&mod_event, 0, sizeof(mod_event));
+		mod_event.events = EPOLLIN;
+		mod_event.data.ptr = server_info;
+		if (epoll_ctl(client.epoll_fd, EPOLL_CTL_MOD, server_info->fd, &mod_event) != 0) {
 			tlog(TLOG_ERROR, "epoll ctl failed, %s", strerror(errno));
 			goto errout;
 		}
@@ -2351,15 +2355,16 @@ static inline int _dns_client_to_hex(int c)
 {
 	if (c > 0x9) {
 		return 'A' + c - 0xA;
-	} else {
-		return '0' + c;
 	}
+
+	return '0' + c;
 }

 static int _dns_client_tls_matchName(const char *host, const char *pattern, int size)
 {
 	int match = -1;
-	int i = 0, j = 0;
+	int i = 0;
+	int j = 0;

 	while (i < size && host[j] != '\0') {
 		if (toupper(pattern[i]) == toupper(host[j])) {
@@ -2533,7 +2538,7 @@ static int _dns_client_process_tls(struct dns_server_info *server_info, struct e
 {
 	int ret = -1;
 	struct epoll_event fd_event;
-	int ssl_ret;
+	int ssl_ret = 0;

 	if (unlikely(server_info->ssl == NULL)) {
 		tlog(TLOG_ERROR, "ssl is invalid.");
@@ -2644,7 +2649,7 @@ static int _dns_client_send_udp(struct dns_server_info *server_info, void *packe
 		return -1;
 	}

-	send_len = sendto(server_info->fd, packet, len, 0, (struct sockaddr *)&server_info->addr, server_info->ai_addrlen);
+	send_len = sendto(server_info->fd, packet, len, 0, &server_info->addr, server_info->ai_addrlen);
 	if (send_len != len) {
 		return -1;
 	}
@@ -2833,7 +2838,7 @@ static int _dns_client_send_packet(struct dns_query_struct *query, void *packet,
 		{
 			server_info = group_member->server;
 			if (server_info->prohibit) {
-				time_t now;
+				time_t now = 0;
 				time(&now);
 				if ((now - 60 < server_info->last_send) && (now - 5 > server_info->last_recv)) {
 					continue;
@@ -2888,7 +2893,7 @@ static int _dns_client_send_packet(struct dns_query_struct *query, void *packet,

 				tlog(TLOG_DEBUG, "send query to %s failed, %s, type: %d", server_info->ip, strerror(send_err),
 					 server_info->type);
-				time_t now;
+				time_t now = 0;
 				time(&now);
 				if (now - 5 > server_info->last_recv || send_err != ENOMEM) {
 					server_info->prohibit = 1;
@@ -2925,12 +2930,12 @@ static int _dns_client_dns_add_ecs(struct dns_query_struct *query, struct dns_pa
 	return dns_add_OPT_ECS(packet, &query->ecs.ecs);
 }

-static int _dns_client_send_query(struct dns_query_struct *query, char *doamin)
+static int _dns_client_send_query(struct dns_query_struct *query, const char *doamin)
 {
 	unsigned char packet_buff[DNS_PACKSIZE];
 	unsigned char inpacket[DNS_IN_PACKSIZE];
 	struct dns_packet *packet = (struct dns_packet *)packet_buff;
-	int encode_len;
+	int encode_len = 0;

 	/* init dns packet head */
 	struct dns_head head;
@@ -2969,8 +2974,7 @@ static int _dns_client_send_query(struct dns_query_struct *query, char *doamin)
 	}

 	if (encode_len > DNS_IN_PACKSIZE) {
-		tlog(TLOG_ERROR, "size is invalid.");
-		abort();
+		BUG("size is invalid.");
 		return -1;
 	}

@@ -2978,7 +2982,7 @@ static int _dns_client_send_query(struct dns_query_struct *query, char *doamin)
 	return _dns_client_send_packet(query, inpacket, encode_len);
 }

-int _dns_client_query_setup_default_ecs(struct dns_query_struct *query)
+static int _dns_client_query_setup_default_ecs(struct dns_query_struct *query)
 {
 	int add_ipv4_ecs = 0;
 	int add_ipv6_ecs = 0;
@@ -3008,7 +3012,7 @@ int _dns_client_query_setup_default_ecs(struct dns_query_struct *query)
 	return 0;
 }

-int _dns_client_query_parser_options(struct dns_query_struct *query, struct dns_query_options *options)
+static int _dns_client_query_parser_options(struct dns_query_struct *query, struct dns_query_options *options)
 {
 	if (options == NULL) {
 		_dns_client_query_setup_default_ecs(query);
@@ -3018,7 +3022,7 @@ int _dns_client_query_parser_options(struct dns_query_struct *query, struct dns_
 	if (options->enable_flag & DNS_QUEY_OPTION_ECS_IP) {
 		struct sockaddr_storage addr;
 		socklen_t addr_len = sizeof(addr);
-		struct dns_opt_ecs *ecs;
+		struct dns_opt_ecs *ecs = NULL;

 		ecs = &query->ecs.ecs;
 		getaddr_by_host(options->ecs_ip.ip, (struct sockaddr *)&addr, &addr_len);
@@ -3029,13 +3033,13 @@ int _dns_client_query_parser_options(struct dns_query_struct *query, struct dns_

 		switch (addr.ss_family) {
 		case AF_INET: {
-			struct sockaddr_in *addr_in;
+			struct sockaddr_in *addr_in = NULL;
 			addr_in = (struct sockaddr_in *)&addr;
 			ecs->family = DNS_OPT_ECS_FAMILY_IPV4;
 			memcpy(&ecs->addr, &addr_in->sin_addr.s_addr, 4);
 		} break;
 		case AF_INET6: {
-			struct sockaddr_in6 *addr_in6;
+			struct sockaddr_in6 *addr_in6 = NULL;
 			addr_in6 = (struct sockaddr_in6 *)&addr;
 			if (IN6_IS_ADDR_V4MAPPED(&addr_in6->sin6_addr)) {
 				memcpy(&ecs->addr, addr_in6->sin6_addr.s6_addr + 12, 4);
@@ -3072,8 +3076,8 @@ int _dns_client_query_parser_options(struct dns_query_struct *query, struct dns_
 	return 0;
 }

-int dns_client_query(char *domain, int qtype, dns_client_callback callback, void *user_ptr, const char *group_name,
-					 struct dns_query_options *options)
+int dns_client_query(const char *domain, int qtype, dns_client_callback callback, void *user_ptr,
+					 const char *group_name, struct dns_query_options *options)
 {
 	struct dns_query_struct *query = NULL;
 	int ret = 0;
@@ -3150,7 +3154,8 @@ errout:

 static void _dns_client_check_servers(void)
 {
-	struct dns_server_info *server_info, *tmp;
+	struct dns_server_info *server_info = NULL;
+	struct dns_server_info *tmp = NULL;
 	static unsigned int second_count = 0;

 	second_count++;
@@ -3175,7 +3180,7 @@ static void _dns_client_check_servers(void)
 	pthread_mutex_unlock(&client.server_list_lock);
 }

-static int _dns_client_pending_server_resolve(char *domain, dns_rtcode_t rtcode, dns_type_t addr_type, char *ip,
+static int _dns_client_pending_server_resolve(const char *domain, dns_rtcode_t rtcode, dns_type_t addr_type, char *ip,
 											  unsigned int ping_time, void *user_ptr)
 {
 	struct dns_server_pending *pending = user_ptr;
@@ -3205,7 +3210,8 @@ static int _dns_client_pending_server_resolve(char *domain, dns_rtcode_t rtcode,

 static int _dns_client_add_pendings(struct dns_server_pending *pending, char *ip)
 {
-	struct dns_server_pending_group *group, *tmp;
+	struct dns_server_pending_group *group = NULL;
+	struct dns_server_pending_group *tmp = NULL;

 	if (_dns_client_add_server_pending(ip, pending->host, pending->port, pending->type, &pending->flags, 0) != 0) {
 		return -1;
@@ -3226,21 +3232,33 @@ static int _dns_client_add_pendings(struct dns_server_pending *pending, char *ip

 static void _dns_client_remove_all_pending_servers(void)
 {
-	struct dns_server_pending *pending, *tmp;
+	struct dns_server_pending *pending = NULL;
+	struct dns_server_pending *tmp = NULL;
+	LIST_HEAD(remove_list);

 	pthread_mutex_lock(&pending_server_mutex);
 	list_for_each_entry_safe(pending, tmp, &pending_servers, list)
 	{
 		list_del_init(&pending->list);
-		_dns_client_server_pending_release_lck(pending);
+		list_add(&pending->retry_list, &remove_list);
+		_dns_client_server_pending_get(pending);
 	}
 	pthread_mutex_unlock(&pending_server_mutex);
+
+	list_for_each_entry_safe(pending, tmp, &remove_list, retry_list)
+	{
+		list_del_init(&pending->retry_list);
+		_dns_client_server_pending_release(pending);
+		_dns_client_server_pending_remove(pending);
+	}
 }

 static void _dns_client_add_pending_servers(void)
 {
-	struct dns_server_pending *pending, *tmp;
+	struct dns_server_pending *pending = NULL;
+	struct dns_server_pending *tmp = NULL;
 	static int dely = 0;
+	LIST_HEAD(retry_list);

 	/* add pending server after 3 seconds */
 	if (++dely < 3) {
@@ -3250,6 +3268,13 @@ static void _dns_client_add_pending_servers(void)

 	pthread_mutex_lock(&pending_server_mutex);
 	list_for_each_entry_safe(pending, tmp, &pending_servers, list)
+	{
+		list_add(&pending->retry_list, &retry_list);
+		_dns_client_server_pending_get(pending);
+	}
+	pthread_mutex_unlock(&pending_server_mutex);
+
+	list_for_each_entry_safe(pending, tmp, &retry_list, retry_list)
 	{
 		/* send dns type A, AAAA query to bootstrap DNS server */
 		int add_success = 0;
@@ -3259,7 +3284,8 @@ static void _dns_client_add_pending_servers(void)
 			pending->query_v4 = 1;
 			_dns_client_server_pending_get(pending);
 			if (dns_server_query(pending->host, DNS_T_A, 0, _dns_client_pending_server_resolve, pending) != 0) {
-				_dns_client_server_pending_release_lck(pending);
+				_dns_client_server_pending_release(pending);
+				pending->query_v4 = 0;
 			}
 		}

@@ -3267,10 +3293,14 @@ static void _dns_client_add_pending_servers(void)
 			pending->query_v6 = 1;
 			_dns_client_server_pending_get(pending);
 			if (dns_server_query(pending->host, DNS_T_AAAA, 0, _dns_client_pending_server_resolve, pending) != 0) {
-				_dns_client_server_pending_release_lck(pending);
+				_dns_client_server_pending_release(pending);
+				pending->query_v4 = 0;
 			}
 		}

+		list_del_init(&pending->retry_list);
+		_dns_client_server_pending_release(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]) {
@@ -3291,14 +3321,17 @@ static void _dns_client_add_pending_servers(void)
 		}

 		pending->retry_cnt++;
-		if (pending->retry_cnt >= DNS_PENDING_SERVER_RETRY || add_success) {
+		if (pending->retry_cnt == 1) {
+			continue;
+		}
+
+		if (pending->retry_cnt - 1 > DNS_PENDING_SERVER_RETRY || add_success) {
 			if (add_success == 0) {
 				tlog(TLOG_WARN, "add pending DNS server %s failed.", pending->host);
 			}
-			list_del_init(&pending->list);
-			_dns_client_server_pending_release_lck(pending);
+			_dns_client_server_pending_remove(pending);
 		} else {
-			tlog(TLOG_INFO, "add pending DNS server %s failed, retry %d...", pending->host, pending->retry_cnt);
+			tlog(TLOG_INFO, "add pending DNS server %s failed, retry %d...", pending->host, pending->retry_cnt - 1);
 			pending->query_v4 = 0;
 			pending->query_v6 = 0;
 		}
@@ -3312,10 +3345,9 @@ static void _dns_client_add_pending_servers(void)
 				return;
 			}

-			_dns_client_server_pending_release_lck(pending);
+			_dns_client_server_pending_release(pending);
 		}
 	}
-	pthread_mutex_unlock(&pending_server_mutex);
 }

 static void _dns_client_period_run_second(void)
@@ -3327,7 +3359,8 @@ static void _dns_client_period_run_second(void)

 static void _dns_client_period_run(void)
 {
-	struct dns_query_struct *query, *tmp;
+	struct dns_query_struct *query = NULL;
+	struct dns_query_struct *tmp = NULL;
 	static unsigned int msec = 0;
 	msec++;

@@ -3366,24 +3399,22 @@ static void _dns_client_period_run(void)
 	if (msec % 10 == 0) {
 		_dns_client_period_run_second();
 	}
-
-	return;
 }

 static void *_dns_client_work(void *arg)
 {
 	struct epoll_event events[DNS_MAX_EVENTS + 1];
-	int num;
-	int i;
+	int num = 0;
+	int i = 0;
 	unsigned long now = {0};
 	unsigned int sleep = 100;
-	int sleep_time;
+	int sleep_time = 0;
 	unsigned long expect_time = 0;

 	sleep_time = sleep;
 	now = get_tick_count() - sleep;
 	expect_time = now + sleep;
-	while (client.run) {
+	while (atomic_read(&client.run)) {
 		now = get_tick_count();
 		if (now >= expect_time) {
 			_dns_client_period_run();
@@ -3427,7 +3458,7 @@ int dns_client_set_ecs(char *ip, int subnet)

 	switch (addr.ss_family) {
 	case AF_INET: {
-		struct sockaddr_in *addr_in;
+		struct sockaddr_in *addr_in = NULL;
 		addr_in = (struct sockaddr_in *)&addr;
 		memcpy(&client.ecs_ipv4.ecs.addr, &addr_in->sin_addr.s_addr, 4);
 		client.ecs_ipv4.ecs.source_prefix = subnet;
@@ -3436,7 +3467,7 @@ int dns_client_set_ecs(char *ip, int subnet)
 		client.ecs_ipv4.enable = 1;
 	} break;
 	case AF_INET6: {
-		struct sockaddr_in6 *addr_in6;
+		struct sockaddr_in6 *addr_in6 = NULL;
 		addr_in6 = (struct sockaddr_in6 *)&addr;
 		if (IN6_IS_ADDR_V4MAPPED(&addr_in6->sin6_addr)) {
 			client.ecs_ipv4.ecs.source_prefix = subnet;
@@ -3461,7 +3492,7 @@ int dns_client_init(void)
 {
 	pthread_attr_t attr;
 	int epollfd = -1;
-	int ret;
+	int ret = 0;

 	if (client.epoll_fd > 0) {
 		return -1;
@@ -3492,7 +3523,7 @@ int dns_client_init(void)

 	client.default_group = _dns_client_get_group(DNS_SERVER_GROUP_DEFAULT);
 	client.epoll_fd = epollfd;
-	client.run = 1;
+	atomic_set(&client.run, 1);

 	/* start work task */
 	ret = pthread_create(&client.tid, &attr, _dns_client_work, NULL);
@@ -3503,10 +3534,11 @@ int dns_client_init(void)

 	return 0;
 errout:
-	if (client.tid > 0) {
+	if (client.tid) {
 		void *retval = NULL;
-		client.run = 0;
+		atomic_set(&client.run, 0);
 		pthread_join(client.tid, &retval);
+		client.tid = 0;
 	}

 	if (epollfd) {
@@ -3521,10 +3553,11 @@ errout:

 void dns_client_exit(void)
 {
-	if (client.tid > 0) {
+	if (client.tid) {
 		void *ret = NULL;
-		client.run = 0;
+		atomic_set(&client.run, 0);
 		pthread_join(client.tid, &ret);
+		client.tid = 0;
 	}

 	/* free all resouces */
--- a/src/dns_client.h
+++ b/src/dns_client.h
@@ -56,7 +56,7 @@ int dns_client_set_ecs(char *ip, int subnet);

 struct dns_server_info;
 /* query result notify function */
-typedef int (*dns_client_callback)(char *domain, dns_result_type rtype, struct dns_server_info *server_info,
+typedef int (*dns_client_callback)(const char *domain, dns_result_type rtype, struct dns_server_info *server_info,
 								   struct dns_packet *packet, unsigned char *inpacket, int inpacket_len,
 								   void *user_ptr);

@@ -80,7 +80,7 @@ struct dns_query_options {
 };

 /* query domain */
-int dns_client_query(char *domain, int qtype, dns_client_callback callback, void *user_ptr, const char *group_name,
+int dns_client_query(const char *domain, int qtype, dns_client_callback callback, void *user_ptr, const char *group_name,
 					 struct dns_query_options *options);

 void dns_client_exit(void);
@@ -128,13 +128,13 @@ int dns_client_add_server(char *server_ip, int port, dns_server_type_t server_ty
 /* remove remote dns server */
 int dns_client_remove_server(char *server_ip, int port, dns_server_type_t server_type);

-int dns_client_add_group(char *group_name);
+int dns_client_add_group(const char *group_name);

-int dns_client_add_to_group(char *group_name, char *server_ip, int port, dns_server_type_t server_type);
+int dns_client_add_to_group(const char *group_name, char *server_ip, int port, dns_server_type_t server_type);

-int dns_client_remove_from_group(char *group_name, char *server_ip, int port, dns_server_type_t server_type);
+int dns_client_remove_from_group(const char *group_name, char *server_ip, int port, dns_server_type_t server_type);

-int dns_client_remove_group(char *group_name);
+int dns_client_remove_group(const char *group_name);

 int dns_server_num(void);

--- a/src/dns_conf.c
+++ b/src/dns_conf.c
@@ -46,8 +46,8 @@ struct dns_group_table dns_group_table;

 struct dns_ptr_table dns_ptr_table;

-char dns_conf_dnsmasq_lease_file[DNS_MAX_PATH];
-time_t dns_conf_dnsmasq_lease_file_time;
+static char dns_conf_dnsmasq_lease_file[DNS_MAX_PATH];
+static time_t dns_conf_dnsmasq_lease_file_time;

 struct dns_hosts_table dns_hosts_table;
 int dns_hosts_record_num;
@@ -59,6 +59,14 @@ int dns_conf_tcp_idle_time = 120;

 int dns_conf_max_reply_ip_num = DNS_MAX_REPLY_IP_NUM;

+static struct config_enum_list dns_conf_response_mode_enum[] = {
+	{"first-ping", DNS_RESPONSE_MODE_FIRST_PING_IP},
+	{"fastest-ip", DNS_RESPONSE_MODE_FASTEST_IP},
+	{"fastest-response", DNS_RESPONSE_MODE_FASTEST_RESPONSE},
+	{0, 0}};
+
+enum response_mode_type dns_conf_response_mode;
+
 /* cache */
 int dns_conf_cachesize = DEFAULT_DNS_CACHE_SIZE;
 int dns_conf_prefetch = 0;
@@ -80,7 +88,7 @@ struct dns_domain_check_orders dns_conf_check_orders = {
 			{.type = DOMAIN_CHECK_TCP, .tcp_port = 443},
 		},
 };
-int dns_has_cap_ping = 0;
+static int dns_has_cap_ping = 0;

 /* logging */
 int dns_conf_log_level = TLOG_ERROR;
@@ -122,6 +130,9 @@ int dns_conf_ipset_timeout_enable;

 char dns_conf_user[DNS_CONF_USRNAME_LEN];

+int dns_save_fail_packet;
+char dns_save_fail_packet_dir[DNS_MAX_PATH];
+
 /* ECS */
 struct dns_edns_client_subnet dns_conf_ipv4_ecs;
 struct dns_edns_client_subnet dns_conf_ipv6_ecs;
@@ -249,7 +260,7 @@ static void _config_group_table_destroy(void)
 {
 	struct dns_server_groups *group = NULL;
 	struct hlist_node *tmp = NULL;
-	int i;
+	unsigned long i = 0;

 	hash_for_each_safe(dns_group_table.group, i, tmp, group, node)
 	{
@@ -261,7 +272,7 @@ static void _config_group_table_destroy(void)
 static int _config_server(int argc, char *argv[], dns_server_type_t type, int default_port)
 {
 	int index = dns_conf_server_num;
-	struct dns_servers *server;
+	struct dns_servers *server = NULL;
 	int port = -1;
 	char *ip = NULL;
 	int opt = 0;
@@ -455,7 +466,7 @@ static int _config_domain_rule_add(char *domain, enum domain_rule type, void *ru

 	/* Reverse string, for suffix match */
 	len = strlen(domain);
-	if (len >= sizeof(domain_key)) {
+	if (len >= (int)sizeof(domain_key)) {
 		tlog(TLOG_ERROR, "domain name %s too long", domain);
 		goto errout;
 	}
@@ -516,7 +527,7 @@ static int _config_domain_rule_flag_set(char *domain, unsigned int flag, unsigne
 	int len = 0;

 	len = strlen(domain);
-	if (len >= sizeof(domain_key)) {
+	if (len >= (int)sizeof(domain_key)) {
 		tlog(TLOG_ERROR, "domain %s too long", domain);
 		return -1;
 	}
@@ -574,7 +585,7 @@ static void _config_ipset_table_destroy(void)
 {
 	struct dns_ipset_name *ipset_name = NULL;
 	struct hlist_node *tmp = NULL;
-	int i;
+	unsigned long i = 0;

 	hash_for_each_safe(dns_ipset_table.ipset, i, tmp, ipset_name, node)
 	{
@@ -619,8 +630,8 @@ static int _conf_domain_rule_ipset(char *domain, const char *ipsetname)
 	struct dns_ipset_rule *ipset_rule = NULL;
 	const char *ipset = NULL;
 	char *copied_name = NULL;
-	enum domain_rule type;
-	int ignore_flag;
+	enum domain_rule type = 0;
+	int ignore_flag = 0;

 	copied_name = strdup(ipsetname);

@@ -630,10 +641,10 @@ static int _conf_domain_rule_ipset(char *domain, const char *ipsetname)

 	for (char *tok = strtok(copied_name, ","); tok; tok = strtok(NULL, ",")) {
 		if (tok[0] == '#') {
-			if (strncmp(tok, "#6:", 3u) == 0) {
+			if (strncmp(tok, "#6:", 3U) == 0) {
 				type = DOMAIN_RULE_IPSET_IPV6;
 				ignore_flag = DOMAIN_FLAG_IPSET_IPV6_IGN;
-			} else if (strncmp(tok, "#4:", 3u) == 0) {
+			} else if (strncmp(tok, "#4:", 3U) == 0) {
 				type = DOMAIN_RULE_IPSET_IPV4;
 				ignore_flag = DOMAIN_FLAG_IPSET_IPV4_IGN;
 			} else {
@@ -710,7 +721,7 @@ static int _conf_domain_rule_address(char *domain, const char *domain_address)
 	struct dns_address_IPV6 *address_ipv6 = NULL;
 	void *address = NULL;
 	char ip[MAX_IP_LEN];
-	int port;
+	int port = 0;
 	struct sockaddr_storage addr;
 	socklen_t addr_len = sizeof(addr);
 	enum domain_rule type = 0;
@@ -762,7 +773,7 @@ static int _conf_domain_rule_address(char *domain, const char *domain_address)

 		switch (addr.ss_family) {
 		case AF_INET: {
-			struct sockaddr_in *addr_in;
+			struct sockaddr_in *addr_in = NULL;
 			address_ipv4 = malloc(sizeof(*address_ipv4));
 			if (address_ipv4 == NULL) {
 				goto errout;
@@ -774,7 +785,7 @@ static int _conf_domain_rule_address(char *domain, const char *domain_address)
 			address = address_ipv4;
 		} break;
 		case AF_INET6: {
-			struct sockaddr_in6 *addr_in6;
+			struct sockaddr_in6 *addr_in6 = NULL;
 			addr_in6 = (struct sockaddr_in6 *)&addr;
 			if (IN6_IS_ADDR_V4MAPPED(&addr_in6->sin6_addr)) {
 				address_ipv4 = malloc(sizeof(*address_ipv4));
@@ -836,8 +847,8 @@ errout:
 static int _config_speed_check_mode_parser(struct dns_domain_check_orders *check_orders, const char *mode)
 {
 	char tmpbuff[DNS_MAX_OPT_LEN];
-	char *field;
-	char *ptr;
+	char *field = NULL;
+	char *ptr = NULL;
 	int order = 0;
 	int port = 80;
 	int i = 0;
@@ -910,7 +921,7 @@ static int _config_speed_check_mode(void *data, int argc, char *argv[])
 static int _config_bind_ip(int argc, char *argv[], DNS_BIND_TYPE type)
 {
 	int index = dns_conf_bind_ip_num;
-	struct dns_bind_ip *bind_ip;
+	struct dns_bind_ip *bind_ip = NULL;
 	char *ip = NULL;
 	int opt = 0;
 	char group_name[DNS_GROUP_NAME_LEN];
@@ -1022,7 +1033,7 @@ static int _config_bind_ip(int argc, char *argv[], DNS_BIND_TYPE type)
 	bind_ip->flags = server_flag;
 	bind_ip->group = group;
 	dns_conf_bind_ip_num++;
-	tlog(TLOG_DEBUG, "bind ip %s, type:%d, flag: %X", ip, type, server_flag);
+	tlog(TLOG_DEBUG, "bind ip %s, type: %d, flag: %X", ip, type, server_flag);

 	return 0;

@@ -1144,8 +1155,8 @@ errout:

 static radix_node_t *_create_addr_node(char *addr)
 {
-	radix_node_t *node;
-	void *p;
+	radix_node_t *node = NULL;
+	void *p = NULL;
 	prefix_t prefix;
 	const char *errmsg = NULL;
 	radix_tree_t *tree = NULL;
@@ -1212,7 +1223,7 @@ static int _config_iplist_rule(char *subnet, enum address_rule rule)

 static int _config_qtype_soa(void *data, int argc, char *argv[])
 {
-	struct dns_qtype_soa_list *soa_list;
+	struct dns_qtype_soa_list *soa_list = NULL;
 	int i = 0;

 	if (argc <= 1) {
@@ -1242,7 +1253,7 @@ static void _config_qtype_soa_table_destroy(void)
 {
 	struct dns_qtype_soa_list *soa_list = NULL;
 	struct hlist_node *tmp = NULL;
-	int i;
+	unsigned long i = 0;

 	hash_for_each_safe(dns_qtype_soa_table.qtype, i, tmp, soa_list, node)
 	{
@@ -1505,7 +1516,7 @@ static int _conf_ptr_add(const char *hostname, const char *ip)
 {
 	struct dns_ptr *ptr = NULL;
 	struct sockaddr_storage addr;
-	unsigned char *paddr;
+	unsigned char *paddr = NULL;
 	socklen_t addr_len = sizeof(addr);
 	char ptr_domain[DNS_MAX_PTR_LEN];

@@ -1515,13 +1526,13 @@ static int _conf_ptr_add(const char *hostname, const char *ip)

 	switch (addr.ss_family) {
 	case AF_INET: {
-		struct sockaddr_in *addr_in;
+		struct sockaddr_in *addr_in = NULL;
 		addr_in = (struct sockaddr_in *)&addr;
 		paddr = (unsigned char *)&(addr_in->sin_addr.s_addr);
 		snprintf(ptr_domain, sizeof(ptr_domain), "%d.%d.%d.%d.in-addr.arpa", paddr[3], paddr[2], paddr[1], paddr[0]);
 	} break;
 	case AF_INET6: {
-		struct sockaddr_in6 *addr_in6;
+		struct sockaddr_in6 *addr_in6 = NULL;
 		addr_in6 = (struct sockaddr_in6 *)&addr;
 		if (IN6_IS_ADDR_V4MAPPED(&addr_in6->sin6_addr)) {
 			paddr = addr_in6->sin6_addr.s6_addr + 12;
@@ -1565,7 +1576,7 @@ static void _config_ptr_table_destroy(void)
 {
 	struct dns_ptr *ptr = NULL;
 	struct hlist_node *tmp = NULL;
-	int i;
+	unsigned long i = 0;

 	hash_for_each_safe(dns_ptr_table.ptr, i, tmp, ptr, node)
 	{
@@ -1617,7 +1628,7 @@ static int _conf_host_add(const char *hostname, const char *ip, dns_hosts_type h
 {
 	struct dns_hosts *host = NULL;
 	struct dns_hosts *host_other __attribute__((unused));
-	;
+
 	struct sockaddr_storage addr;
 	socklen_t addr_len = sizeof(addr);
 	int dns_type = 0;
@@ -1633,7 +1644,7 @@ static int _conf_host_add(const char *hostname, const char *ip, dns_hosts_type h
 		dns_type_other = DNS_T_AAAA;
 		break;
 	case AF_INET6: {
-		struct sockaddr_in6 *addr_in6;
+		struct sockaddr_in6 *addr_in6 = NULL;
 		addr_in6 = (struct sockaddr_in6 *)&addr;
 		if (IN6_IS_ADDR_V4MAPPED(&addr_in6->sin6_addr)) {
 			dns_type = DNS_T_A;
@@ -1660,13 +1671,13 @@ static int _conf_host_add(const char *hostname, const char *ip, dns_hosts_type h

 	switch (addr.ss_family) {
 	case AF_INET: {
-		struct sockaddr_in *addr_in;
+		struct sockaddr_in *addr_in = NULL;
 		addr_in = (struct sockaddr_in *)&addr;
 		memcpy(host->ipv4_addr, &addr_in->sin_addr.s_addr, 4);
 		host->is_soa = 0;
 	} break;
 	case AF_INET6: {
-		struct sockaddr_in6 *addr_in6;
+		struct sockaddr_in6 *addr_in6 = NULL;
 		addr_in6 = (struct sockaddr_in6 *)&addr;
 		if (IN6_IS_ADDR_V4MAPPED(&addr_in6->sin6_addr)) {
 			memcpy(host->ipv4_addr, addr_in6->sin6_addr.s6_addr + 12, 4);
@@ -1694,7 +1705,7 @@ static int _conf_dhcp_lease_dnsmasq_add(const char *file)
 	char hostname[DNS_MAX_CNAME_LEN];
 	int ret = 0;
 	int line_no = 0;
-	int filed_num;
+	int filed_num = 0;

 	fp = fopen(file, "r");
 	if (fp == NULL) {
@@ -1710,7 +1721,7 @@ static int _conf_dhcp_lease_dnsmasq_add(const char *file)
 			continue;
 		}

-		if (strncmp(hostname, "*", DNS_MAX_CNAME_LEN) == 0) {
+		if (strncmp(hostname, "*", DNS_MAX_CNAME_LEN - 1) == 0) {
 			continue;
 		}

@@ -1760,7 +1771,7 @@ static void _config_host_table_destroy(void)
 {
 	struct dns_hosts *host = NULL;
 	struct hlist_node *tmp = NULL;
-	int i;
+	unsigned long i = 0;

 	hash_for_each_safe(dns_hosts_table.hosts, i, tmp, host, node)
 	{
@@ -1774,7 +1785,7 @@ static void _config_host_table_destroy(void)
 int dns_server_check_update_hosts(void)
 {
 	struct stat statbuf;
-	time_t now;
+	time_t now = 0;

 	if (dns_conf_dnsmasq_lease_file[0] == '\0') {
 		return -1;
@@ -1838,12 +1849,12 @@ static void _config_setup_smartdns_domain(void)
 	}

 	/* get host name again */
-	if (strncmp(hostname, "(none)", DNS_MAX_CNAME_LEN) == 0) {
+	if (strncmp(hostname, "(none)", DNS_MAX_CNAME_LEN - 1) == 0) {
 		gethostname(hostname, DNS_MAX_CNAME_LEN);
 	}

 	/* if hostname is (none), return smartdns */
-	if (strncmp(hostname, "(none)", DNS_MAX_CNAME_LEN) == 0) {
+	if (strncmp(hostname, "(none)", DNS_MAX_CNAME_LEN - 1) == 0) {
 		safe_strncpy(hostname, "smartdns", DNS_MAX_CNAME_LEN);
 	}

@@ -1897,6 +1908,7 @@ static struct config_item _config_item[] = {
 	CONF_INT("rr-ttl-max", &dns_conf_rr_ttl_max, 0, CONF_INT_MAX),
 	CONF_INT("rr-ttl-reply-max", &dns_conf_rr_ttl_reply_max, 0, CONF_INT_MAX),
 	CONF_INT("max-reply-ip-num", &dns_conf_max_reply_ip_num, 1, CONF_INT_MAX),
+	CONF_ENUM("response-mode", &dns_conf_response_mode, &dns_conf_response_mode_enum),
 	CONF_YESNO("force-AAAA-SOA", &dns_conf_force_AAAA_SOA),
 	CONF_YESNO("force-no-CNAME", &dns_conf_force_no_cname),
 	CONF_CUSTOM("force-qtype-SOA", _config_qtype_soa, NULL),
@@ -1911,20 +1923,24 @@ static struct config_item _config_item[] = {
 	CONF_STRING("ca-file", (char *)&dns_conf_ca_file, DNS_MAX_PATH),
 	CONF_STRING("ca-path", (char *)&dns_conf_ca_path, DNS_MAX_PATH),
 	CONF_STRING("user", (char *)&dns_conf_user, sizeof(dns_conf_user)),
+	CONF_YESNO("debug-save-fail-packet", &dns_save_fail_packet),
+	CONF_STRING("debug-save-fail-packet-dir", (char *)&dns_save_fail_packet_dir, sizeof(dns_save_fail_packet_dir)),
 	CONF_CUSTOM("conf-file", config_addtional_file, NULL),
 	CONF_END(),
 };

 static int _conf_printf(const char *file, int lineno, int ret)
 {
-	if (ret == CONF_RET_ERR) {
-		tlog(TLOG_ERROR, "process config file '%s' failed at line %d.", file, lineno);
-		syslog(LOG_NOTICE, "process config file '%s' failed at line %d.", file, lineno);
-		return -1;
-	} else if (ret == CONF_RET_WARN) {
+	switch (ret) {
+	case CONF_RET_ERR:
+	case CONF_RET_WARN:
+	case CONF_RET_BADCONF:
 		tlog(TLOG_WARN, "process config file '%s' failed at line %d.", file, lineno);
 		syslog(LOG_NOTICE, "process config file '%s' failed at line %d.", file, lineno);
 		return -1;
+		break;
+	default:
+		break;
 	}

 	return 0;
@@ -1932,7 +1948,7 @@ static int _conf_printf(const char *file, int lineno, int ret)

 int config_addtional_file(void *data, int argc, char *argv[])
 {
-	char *conf_file;
+	char *conf_file = NULL;
 	char file_path[DNS_MAX_PATH];
 	char file_path_dir[DNS_MAX_PATH];

@@ -2002,7 +2018,8 @@ void dns_server_load_exit(void)

 static int _dns_conf_speed_check_mode_verify(void)
 {
-	int i, j;
+	int i = 0;
+	int j = 0;
 	int print_log = 0;

 	if (dns_has_cap_ping == 1) {
@@ -2031,7 +2048,7 @@ static int _dns_conf_speed_check_mode_verify(void)
 static int _dns_ping_cap_check(void)
 {
 	int has_ping = 0;
-	int has_raw_cap;
+	int has_raw_cap = 0;

 	has_raw_cap = has_network_raw_cap();
 	has_ping = has_unprivileged_ping();
@@ -2056,6 +2073,8 @@ static int _dns_conf_load_pre(void)

 	_dns_ping_cap_check();

+	safe_strncpy(dns_save_fail_packet_dir, SMARTDNS_DEBUG_DIR, sizeof(dns_save_fail_packet_dir));
+
 	return 0;

 errout:
@@ -2066,6 +2085,12 @@ static int _dns_conf_load_post(void)
 {
 	_dns_conf_speed_check_mode_verify();

+	if (dns_conf_cachesize == 0 && dns_conf_response_mode == DNS_RESPONSE_MODE_FASTEST_RESPONSE) {
+		dns_conf_response_mode = DNS_RESPONSE_MODE_FASTEST_IP;
+		tlog(TLOG_WARN, "force set response to %s as cache size is 0",
+			 dns_conf_response_mode_enum[dns_conf_response_mode].name);
+	}
+
 	return 0;
 }

--- a/src/dns_conf.h
+++ b/src/dns_conf.h
@@ -49,9 +49,10 @@ extern "C" {
 #define DEFAULT_DNS_HTTPS_PORT 443
 #define DNS_MAX_CONF_CNAME_LEN 256
 #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_LOG_FILE "/var/log/smartdns/smartdns.log"
+#define SMARTDNS_AUDIT_FILE "/var/log/smartdns/smartdns-audit.log"
 #define SMARTDNS_CACHE_FILE "/tmp/smartdns.cache"
+#define SMARTDNS_DEBUG_DIR "/tmp/smartdns"

 enum domain_rule {
 	DOMAIN_RULE_FLAGS = 0,
@@ -298,6 +299,12 @@ extern int dns_conf_dualstack_ip_allow_force_AAAA;
 extern int dns_conf_dualstack_ip_selection_threshold;

 extern int dns_conf_max_reply_ip_num;
+enum response_mode_type {
+	DNS_RESPONSE_MODE_FIRST_PING_IP = 0,
+	DNS_RESPONSE_MODE_FASTEST_IP,
+	DNS_RESPONSE_MODE_FASTEST_RESPONSE,
+};
+extern enum response_mode_type dns_conf_response_mode;

 extern int dns_conf_rr_ttl;
 extern int dns_conf_rr_ttl_reply_max;
@@ -315,6 +322,9 @@ extern struct dns_edns_client_subnet dns_conf_ipv6_ecs;

 extern char dns_conf_sni_proxy_ip[DNS_MAX_IPLEN];

+extern int dns_save_fail_packet;
+extern char dns_save_fail_packet_dir[DNS_MAX_PATH];
+
 void dns_server_load_exit(void);

 int dns_server_load_conf(const char *file);
--- a/src/dns_server.c
+++ b/src/dns_server.c
--- a/src/dns_server.h
+++ b/src/dns_server.h
@@ -37,11 +37,11 @@ void dns_server_stop(void);
 void dns_server_exit(void);

 /* query result notify function */
-typedef int (*dns_result_callback)(char *domain, dns_rtcode_t rtcode, dns_type_t addr_type, char *ip,
+typedef int (*dns_result_callback)(const char *domain, dns_rtcode_t rtcode, dns_type_t addr_type, char *ip,
 								   unsigned int ping_time, void *user_ptr);

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

 #ifdef __cpluscplus
 }
--- a/src/fast_ping.c
+++ b/src/fast_ping.c
@@ -124,7 +124,7 @@ struct ping_host_struct {
 };

 struct fast_ping_struct {
-	int run;
+	atomic_t run;
 	pthread_t tid;
 	pthread_mutex_t lock;
 	unsigned short ident;
@@ -151,7 +151,7 @@ static int bool_print_log = 1;
 static uint16_t _fast_ping_checksum(uint16_t *header, size_t len)
 {
 	uint32_t sum = 0;
-	int i;
+	unsigned int i = 0;

 	for (i = 0; i < len / sizeof(uint16_t); i++) {
 		sum += ntohs(header[i]);
@@ -262,13 +262,13 @@ static uint32_t _fast_ping_hash_key(unsigned int sid, struct sockaddr *addr)

 	switch (addr->sa_family) {
 	case AF_INET: {
-		struct sockaddr_in *addr_in;
+		struct sockaddr_in *addr_in = NULL;
 		addr_in = (struct sockaddr_in *)addr;
 		sin_addr = &addr_in->sin_addr.s_addr;
 		sin_addr_len = IPV4_ADDR_LEN;
 	} break;
 	case AF_INET6: {
-		struct sockaddr_in6 *addr_in6;
+		struct sockaddr_in6 *addr_in6 = NULL;
 		addr_in6 = (struct sockaddr_in6 *)addr;
 		if (IN6_IS_ADDR_V4MAPPED(&addr_in6->sin6_addr)) {
 			sin_addr = addr_in6->sin6_addr.s6_addr + 12;
@@ -358,7 +358,7 @@ static void _fast_ping_close_host_sock(struct ping_host_struct *ping_host)
 	if (ping_host->fd < 0) {
 		return;
 	}
-	struct epoll_event *event;
+	struct epoll_event *event = NULL;
 	event = (struct epoll_event *)1;
 	epoll_ctl(ping.epoll_fd, EPOLL_CTL_DEL, ping_host->fd, event);
 	close(ping_host->fd);
@@ -442,8 +442,8 @@ static int _fast_ping_sendping_v6(struct ping_host_struct *ping_host)
 	packet->msg.seq = ping_host->seq;
 	icmp6->icmp6_cksum = _fast_ping_checksum((void *)packet, sizeof(struct fast_ping_packet));

-	len = sendto(ping.fd_icmp6, &ping_host->packet, sizeof(struct fast_ping_packet), 0,
-				 (struct sockaddr *)&ping_host->addr, ping_host->addr_len);
+	len = sendto(ping.fd_icmp6, &ping_host->packet, sizeof(struct fast_ping_packet), 0, &ping_host->addr,
+				 ping_host->addr_len);
 	if (len < 0 || len != sizeof(struct fast_ping_packet)) {
 		int err = errno;
 		if (errno == ENETUNREACH || errno == EINVAL || errno == EADDRNOTAVAIL) {
@@ -474,7 +474,7 @@ static int _fast_ping_sendping_v4(struct ping_host_struct *ping_host)
 {
 	struct fast_ping_packet *packet = &ping_host->packet;
 	struct icmp *icmp = &packet->icmp;
-	int len;
+	int len = 0;

 	ping_host->seq++;
 	memset(icmp, 0, sizeof(*icmp));
@@ -491,8 +491,7 @@ static int _fast_ping_sendping_v4(struct ping_host_struct *ping_host)
 	packet->msg.cookie = ping_host->cookie;
 	icmp->icmp_cksum = _fast_ping_checksum((void *)packet, sizeof(struct fast_ping_packet));

-	len = sendto(ping.fd_icmp, packet, sizeof(struct fast_ping_packet), 0, (struct sockaddr *)&ping_host->addr,
-				 ping_host->addr_len);
+	len = sendto(ping.fd_icmp, packet, sizeof(struct fast_ping_packet), 0, &ping_host->addr, ping_host->addr_len);
 	if (len < 0 || len != sizeof(struct fast_ping_packet)) {
 		int err = errno;
 		if (errno == ENETUNREACH || errno == EINVAL || errno == EADDRNOTAVAIL) {
@@ -514,7 +513,7 @@ errout:
 static int _fast_ping_sendping_udp(struct ping_host_struct *ping_host)
 {
 	struct ping_dns_head dns_head;
-	int len;
+	int len = 0;
 	int flag = 0;
 	int fd = 0;

@@ -539,7 +538,7 @@ static int _fast_ping_sendping_udp(struct ping_host_struct *ping_host)
 	dns_head.id = htons(ping_host->sid);
 	dns_head.flag = flag;
 	gettimeofday(&ping_host->last, NULL);
-	len = sendto(fd, &dns_head, sizeof(dns_head), 0, (struct sockaddr *)&ping_host->addr, ping_host->addr_len);
+	len = sendto(fd, &dns_head, sizeof(dns_head), 0, &ping_host->addr, ping_host->addr_len);
 	if (len < 0 || len != sizeof(dns_head)) {
 		int err = errno;
 		if (errno == ENETUNREACH || errno == EINVAL || errno == EADDRNOTAVAIL) {
@@ -561,7 +560,7 @@ errout:
 static int _fast_ping_sendping_tcp(struct ping_host_struct *ping_host)
 {
 	struct epoll_event event;
-	int flags;
+	int flags = 0;
 	int fd = -1;
 	int yes = 1;
 	const int priority = SOCKET_PRIORITY;
@@ -586,7 +585,7 @@ static int _fast_ping_sendping_tcp(struct ping_host_struct *ping_host)
 	set_sock_lingertime(fd, 0);

 	ping_host->seq++;
-	if (connect(fd, (struct sockaddr *)&ping_host->addr, ping_host->addr_len) != 0) {
+	if (connect(fd, &ping_host->addr, ping_host->addr_len) != 0) {
 		if (errno != EINPROGRESS) {
 			char ping_host_name[PING_MAX_HOSTLEN];
 			if (errno == ENETUNREACH || errno == EINVAL || errno == EADDRNOTAVAIL) {
@@ -674,6 +673,12 @@ static int _fast_ping_create_icmp_sock(FAST_PING_TYPE type)
 			}
 		}
 		if (fd < 0) {
+			if (errno == EACCES || errno == EAFNOSUPPORT) {
+				if (bool_print_log == 0) {
+					goto errout;
+				}
+				bool_print_log = 0;
+			}
 			tlog(TLOG_ERROR, "create icmp socket failed, %s\n", strerror(errno));
 			goto errout;
 		}
@@ -690,6 +695,12 @@ static int _fast_ping_create_icmp_sock(FAST_PING_TYPE type)
 		}

 		if (fd < 0) {
+			if (errno == EACCES || errno == EAFNOSUPPORT) {
+				if (bool_print_log == 0) {
+					goto errout;
+				}
+				bool_print_log = 0;
+			}
 			tlog(TLOG_ERROR, "create icmp socket failed, %s\n", strerror(errno));
 			goto errout;
 		}
@@ -711,6 +722,9 @@ static int _fast_ping_create_icmp_sock(FAST_PING_TYPE type)
 	setsockopt(fd, SOL_IP, IP_TTL, &val, sizeof(val));
 	setsockopt(fd, IPPROTO_IP, IP_TOS, &ip_tos, sizeof(ip_tos));

+	icmp_host->fd = fd;
+	icmp_host->type = type;
+
 	memset(&event, 0, sizeof(event));
 	event.events = EPOLLIN;
 	event.data.ptr = icmp_host;
@@ -718,12 +732,14 @@ static int _fast_ping_create_icmp_sock(FAST_PING_TYPE type)
 		goto errout;
 	}

-	icmp_host->fd = fd;
-	icmp_host->type = type;
 	return fd;

 errout:
 	close(fd);
+	if (icmp_host) {
+		icmp_host->fd = -1;
+		icmp_host->type = 0;
+	}
 	return -1;
 }

@@ -883,7 +899,7 @@ static int _fast_ping_get_addr_by_icmp(const char *ip_str, int port, struct addr
 	struct addrinfo *gai = NULL;
 	int socktype = 0;
 	int domain = -1;
-	FAST_PING_TYPE ping_type;
+	FAST_PING_TYPE ping_type = 0;
 	int sockproto = 0;
 	char *service = NULL;

@@ -932,7 +948,7 @@ static int _fast_ping_get_addr_by_tcp(const char *ip_str, int port, struct addri
 {
 	struct addrinfo *gai = NULL;
 	int socktype = 0;
-	FAST_PING_TYPE ping_type;
+	FAST_PING_TYPE ping_type = 0;
 	int sockproto = 0;
 	char *service = NULL;
 	char port_str[MAX_IP_LEN];
@@ -968,7 +984,7 @@ static int _fast_ping_get_addr_by_dns(const char *ip_str, int port, struct addri
 {
 	struct addrinfo *gai = NULL;
 	int socktype = 0;
-	FAST_PING_TYPE ping_type;
+	FAST_PING_TYPE ping_type = 0;
 	int sockproto = 0;
 	char port_str[MAX_IP_LEN];
 	int domain = -1;
@@ -1045,11 +1061,11 @@ struct ping_host_struct *fast_ping_start(PING_TYPE type, const char *host, int c
 {
 	struct ping_host_struct *ping_host = NULL;
 	struct addrinfo *gai = NULL;
-	uint32_t addrkey;
+	uint32_t addrkey = 0;
 	char ip_str[PING_MAX_HOSTLEN];
 	int port = -1;
 	FAST_PING_TYPE ping_type = FAST_PING_END;
-	unsigned int seed;
+	unsigned int seed = 0;
 	int ret = 0;

 	if (parse_ip(host, ip_str, &port) != 0) {
@@ -1114,7 +1130,7 @@ struct ping_host_struct *fast_ping_start(PING_TYPE type, const char *host, int c
 	return ping_host;
 errout_remove:
 	ping_host->ping_callback(ping_host, ping_host->host, PING_RESULT_ERROR, &ping_host->addr, ping_host->addr_len,
-							 ping_host->seq, ping_host->ttl, 0, ping_host->error, ping_host->userptr);
+							 ping_host->seq, ping_host->ttl, NULL, ping_host->error, ping_host->userptr);
 	fast_ping_stop(ping_host);
 	_fast_ping_host_put(ping_host);
 	ping_host = NULL;
@@ -1154,22 +1170,24 @@ static void tv_sub(struct timeval *out, struct timeval *in)
 static struct fast_ping_packet *_fast_ping_icmp6_packet(struct ping_host_struct *ping_host, struct msghdr *msg,
 														u_char *packet_data, int data_len)
 {
-	int icmp_len;
+	int icmp_len = 0;
 	struct fast_ping_packet *packet = (struct fast_ping_packet *)packet_data;
 	struct icmp6_hdr *icmp6 = &packet->icmp6;
-	struct cmsghdr *c;
+	struct cmsghdr *c = NULL;
 	int hops = 0;

 	for (c = CMSG_FIRSTHDR(msg); c; c = CMSG_NXTHDR(msg, c)) {
-		if (c->cmsg_level != IPPROTO_IPV6)
+		if (c->cmsg_level != IPPROTO_IPV6) {
 			continue;
+		}
 		switch (c->cmsg_type) {
 		case IPV6_HOPLIMIT:
 #ifdef IPV6_2292HOPLIMIT
 		case IPV6_2292HOPLIMIT:
 #endif
-			if (c->cmsg_len < CMSG_LEN(sizeof(int)))
+			if (c->cmsg_len < CMSG_LEN(sizeof(int))) {
 				continue;
+			}
 			memcpy(&hops, CMSG_DATA(c), sizeof(hops));
 		}
 	}
@@ -1200,10 +1218,10 @@ static struct fast_ping_packet *_fast_ping_icmp_packet(struct ping_host_struct *
 													   u_char *packet_data, int data_len)
 {
 	struct ip *ip = (struct ip *)packet_data;
-	struct fast_ping_packet *packet;
-	struct icmp *icmp;
-	int hlen;
-	int icmp_len;
+	struct fast_ping_packet *packet = NULL;
+	struct icmp *icmp = NULL;
+	int hlen = 0;
+	int icmp_len = 0;

 	hlen = ip->ip_hl << 2;
 	packet = (struct fast_ping_packet *)(packet_data + hlen);
@@ -1216,6 +1234,11 @@ static struct fast_ping_packet *_fast_ping_icmp_packet(struct ping_host_struct *
 		return NULL;
 	}

+	if (icmp->icmp_type != ICMP_ECHOREPLY) {
+		tlog(TLOG_DEBUG, "icmp type faild, %d:%d", icmp->icmp_type, ICMP_ECHOREPLY);
+		return NULL;
+	}
+
 	if (ping.no_unprivileged_ping) {
 		if (ip->ip_p != IPPROTO_ICMP) {
 			tlog(TLOG_ERROR, "ip type faild, %d:%d", ip->ip_p, IPPROTO_ICMP);
@@ -1228,12 +1251,6 @@ static struct fast_ping_packet *_fast_ping_icmp_packet(struct ping_host_struct *
 		}
 	}

-	if (icmp->icmp_type != ICMP_ECHOREPLY) {
-		tlog(TLOG_DEBUG, "icmp type faild, %d:%d", icmp->icmp_type, ICMP_ECHOREPLY);
-		return NULL;
-	}
-
-
 	return packet;
 }

@@ -1264,18 +1281,18 @@ errout:

 static int _fast_ping_process_icmp(struct ping_host_struct *ping_host, struct timeval *now)
 {
-	int len;
+	int len = 0;
 	u_char inpacket[ICMP_INPACKET_SIZE];
 	struct sockaddr_storage from;
-	struct ping_host_struct *recv_ping_host;
+	struct ping_host_struct *recv_ping_host = NULL;
 	struct fast_ping_packet *packet = NULL;
 	socklen_t from_len = sizeof(from);
-	uint32_t addrkey;
+	uint32_t addrkey = 0;
 	struct timeval tvresult = *now;
 	struct timeval *tvsend = NULL;
-	unsigned int sid;
-	unsigned int seq;
-	unsigned int cookie;
+	unsigned int sid = 0;
+	unsigned int seq = 0;
+	unsigned int cookie = 0;
 	struct msghdr msg;
 	struct iovec iov;
 	char ans_data[4096];
@@ -1392,20 +1409,20 @@ errout:

 static int _fast_ping_process_udp(struct ping_host_struct *ping_host, struct timeval *now)
 {
-	int len;
+	ssize_t len = 0;
 	u_char inpacket[ICMP_INPACKET_SIZE];
 	struct sockaddr_storage from;
-	struct ping_host_struct *recv_ping_host;
+	struct ping_host_struct *recv_ping_host = NULL;
 	struct ping_dns_head *dns_head = NULL;
 	socklen_t from_len = sizeof(from);
-	uint32_t addrkey;
+	uint32_t addrkey = 0;
 	struct timeval tvresult = *now;
 	struct timeval *tvsend = NULL;
-	unsigned int sid;
+	unsigned int sid = 0;
 	struct msghdr msg;
 	struct iovec iov;
 	char ans_data[4096];
-	struct cmsghdr *cmsg;
+	struct cmsghdr *cmsg = NULL;
 	int ttl = 0;

 	memset(&msg, 0, sizeof(msg));
@@ -1440,7 +1457,7 @@ static int _fast_ping_process_udp(struct ping_host_struct *ping_host, struct tim

 	from_len = msg.msg_namelen;
 	dns_head = (struct ping_dns_head *)inpacket;
-	if (len < sizeof(*dns_head)) {
+	if (len < (ssize_t)sizeof(*dns_head)) {
 		goto errout;
 	}

@@ -1515,7 +1532,7 @@ static void _fast_ping_remove_all(void)
 	struct ping_host_struct *ping_host = NULL;
 	struct ping_host_struct *ping_host_tmp = NULL;
 	struct hlist_node *tmp = NULL;
-	int i;
+	unsigned long i = 0;

 	LIST_HEAD(remove_list);

@@ -1537,11 +1554,11 @@ static void _fast_ping_period_run(void)
 	struct ping_host_struct *ping_host = NULL;
 	struct ping_host_struct *ping_host_tmp = NULL;
 	struct hlist_node *tmp = NULL;
-	int i = 0;
+	unsigned long i = 0;
 	struct timeval now;
 	struct timezone tz;
 	struct timeval interval;
-	int64_t millisecond;
+	int64_t millisecond = 0;
 	gettimeofday(&now, &tz);
 	LIST_HEAD(action);

@@ -1607,8 +1624,8 @@ static void _fast_ping_period_run(void)
 static void *_fast_ping_work(void *arg)
 {
 	struct epoll_event events[PING_MAX_EVENTS + 1];
-	int num;
-	int i;
+	int num = 0;
+	int i = 0;
 	unsigned long now = {0};
 	struct timeval tvnow = {0};
 	int sleep = 100;
@@ -1618,7 +1635,7 @@ static void *_fast_ping_work(void *arg)
 	sleep_time = sleep;
 	now = get_tick_count() - sleep;
 	expect_time = now + sleep;
-	while (ping.run) {
+	while (atomic_read(&ping.run)) {
 		now = get_tick_count();
 		if (now >= expect_time) {
 			_fast_ping_period_run();
@@ -1658,7 +1675,7 @@ int fast_ping_init(void)
 {
 	pthread_attr_t attr;
 	int epollfd = -1;
-	int ret;
+	int ret = 0;
 	bool_print_log = 1;

 	if (ping.epoll_fd > 0) {
@@ -1680,7 +1697,7 @@ int fast_ping_init(void)
 	ping.epoll_fd = epollfd;
 	ping.no_unprivileged_ping = !has_unprivileged_ping();
 	ping.ident = (getpid() & 0XFFFF);
-	ping.run = 1;
+	atomic_set(&ping.run, 1);
 	ret = pthread_create(&ping.tid, &attr, _fast_ping_work, NULL);
 	if (ret != 0) {
 		tlog(TLOG_ERROR, "create ping work thread failed, %s\n", strerror(errno));
@@ -1689,10 +1706,11 @@ int fast_ping_init(void)

 	return 0;
 errout:
-	if (ping.tid > 0) {
+	if (ping.tid) {
 		void *retval = NULL;
-		ping.run = 0;
+		atomic_set(&ping.run, 0);
 		pthread_join(ping.tid, &retval);
+		ping.tid = 0;
 	}

 	if (epollfd) {
@@ -1730,10 +1748,11 @@ static void _fast_ping_close_fds(void)

 void fast_ping_exit(void)
 {
-	if (ping.tid > 0) {
+	if (ping.tid) {
 		void *ret = NULL;
-		ping.run = 0;
+		atomic_set(&ping.run, 0);
 		pthread_join(ping.tid, &ret);
+		ping.tid = 0;
 	}

 	_fast_ping_close_fds();
--- a/src/http_parse.c
+++ b/src/http_parse.c
@@ -108,7 +108,7 @@ struct http_head_fields *http_head_first_fields(struct http_head *http_head)

 const char *http_head_get_fields_value(struct http_head *http_head, const char *name)
 {
-	unsigned long key;
+	uint32_t key;
 	struct http_head_fields *filed;

 	key = hash_string(name);
@@ -193,7 +193,7 @@ int http_head_get_data_len(struct http_head *http_head)

 static int _http_head_add_fields(struct http_head *http_head, char *name, char *value)
 {
-	unsigned long key = 0;
+	uint32_t key = 0;
 	struct http_head_fields *fields = NULL;
 	fields = malloc(sizeof(*fields));
 	if (fields == NULL) {
--- a/src/include/atomic.h
+++ b/src/include/atomic.h
@@ -20,6 +20,11 @@
 #ifndef _GENERIC_ATOMIC_H
 #define _GENERIC_ATOMIC_H

+#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
+
+#define READ_ONCE(x) \
+({ typeof(x) ___x = ACCESS_ONCE(x); ___x; })
+
 /**
 * Atomic type.
 */
@@ -35,14 +40,20 @@ typedef struct {
 *
 * Atomically reads the value of @v.
 */
-#define atomic_read(v) ((v)->counter)
+static inline int atomic_read(const atomic_t *v)
+{
+	return READ_ONCE((v)->counter);
+}

 /**
 * Set atomic variable
 * @param v pointer of type atomic_t
 * @param i required value
 */
-#define atomic_set(v,i) (((v)->counter) = (i))
+static inline void atomic_set(atomic_t *v, int i)
+{
+    v->counter = i;
+}

 /**
 * Add to the atomic variable
--- a/src/include/conf.h
+++ b/src/include/conf.h
@@ -30,6 +30,7 @@
 #define CONF_RET_ERR -1
 #define CONF_RET_WARN -2
 #define CONF_RET_NOENT -3
+#define CONF_RET_BADCONF -4

 struct config_item {
 	const char *item;
@@ -63,6 +64,16 @@ struct config_item_size {
 	size_t max;
 };

+struct config_enum_list {
+	char *name;
+	int id;
+};
+
+struct config_enum {
+	int *data;
+	struct config_enum_list *list;
+};
+
 #define CONF_INT(key, value, min_value, max_value)                                                                     \
 	{                                                                                                                  \
 		key, conf_int, &(struct config_item_int)                                                                       \
@@ -91,6 +102,15 @@ struct config_item_size {
 			.data = value, .min = min_value, .max = max_value                                                          \
 		}                                                                                                              \
 	}
+
+#define CONF_ENUM(key, value, enum)                                                                                    \
+	{                                                                                                                  \
+		key, conf_enum, &(struct config_enum)                                                                          \
+		{                                                                                                              \
+			.data = (int *)value, .list = (struct config_enum_list *)enum                                              \
+		}                                                                                                              \
+	}
+
 /*
 * func: int (*func)(void *data, int argc, char *argv[]);
 */
@@ -117,6 +137,8 @@ extern int conf_yesno(const char *item, void *data, int argc, char *argv[]);

 extern int conf_size(const char *item, void *data, int argc, char *argv[]);

+extern int conf_enum(const char *item, void *data, int argc, char *argv[]);
+
 /*
 * Example:
 *  int num = 0;
--- a/src/include/hash.h
+++ b/src/include/hash.h
@@ -219,14 +219,16 @@ static inline uint32_t hash32_ptr(const void *ptr)
 	return (uint32_t)val;
 }

-static inline unsigned long
-hash_string(const char *str)
+static inline uint32_t hash_string(const char *s)
 {
-	unsigned long v = 0;
-    const char *c;
-	for (c = str; *c; )
-		v = (((v << 1) + (v >> 14)) ^ (*c++)) & 0x3fff;
-	return(v);
+    uint32_t h = 0;
+
+    while (*s) {
+        h = h * 31 + *s;
+        s++;
+    }
+
+    return h;
 }

 #endif /* _GENERIC_HASH_H */
--- a/src/lib/art.c
+++ b/src/lib/art.c
@@ -1016,7 +1016,7 @@ static void art_copy_key(art_leaf *leaf, unsigned char *key, int *key_len)
 		return;
 	}

-	len = leaf->key_len > *key_len ? *key_len : leaf->key_len;
+	len = (int)leaf->key_len > *key_len ? *key_len : (int)leaf->key_len;
 	memcpy(key, leaf->key, len);
 	*key_len = len;
 }
--- a/src/lib/conf.c
+++ b/src/lib/conf.c
@@ -97,7 +97,6 @@ int conf_yesno(const char *item, void *data, int argc, char *argv[])

 int conf_size(const char *item, void *data, int argc, char *argv[])
 {
-	/* read dns cache size */
 	int base = 1;
 	size_t size = 0;
 	int num = 0;
@@ -129,7 +128,32 @@ int conf_size(const char *item, void *data, int argc, char *argv[])
 	return 0;
 }

-void conf_getopt_reset(void)
+int conf_enum(const char *item, void *data, int argc, char *argv[])
+{
+	struct config_enum *item_enum = data;
+	char *enum_name = argv[1];
+	int i = 0;
+
+	if (argc <= 0) {
+		return -1;
+	}
+
+	for (i = 0; item_enum->list[i].name != NULL; i++) {
+		if (strcmp(enum_name, item_enum->list[i].name) == 0) {
+			*(item_enum->data) = item_enum->list[i].id;
+			return 0;
+		}
+	}
+
+	printf("Not found config value '%s', valid value is:\n", enum_name);
+	for (i = 0; item_enum->list[i].name != NULL; i++) {
+		printf(" %s\n", item_enum->list[i].name);
+	}
+
+	return -1;
+}
+
+static void conf_getopt_reset(void)
 {
 	static struct option long_options[] = {{"-", 0, 0, 0}, {0, 0, 0, 0}};
 	int argc = 2;
@@ -144,7 +168,7 @@ void conf_getopt_reset(void)
 	optopt = 0;
 }

-int conf_parse_args(char *key, char *value, int *argc, char **argv)
+static int conf_parse_args(char *key, char *value, int *argc, char **argv)
 {
 	char *start = NULL;
 	char *ptr = value;
@@ -205,12 +229,9 @@ int conf_parse_args(char *key, char *value, int *argc, char **argv)
 	return 0;
 }

-void load_exit(void)
-{
-	return;
-}
+void load_exit(void) {}

-int load_conf_printf(const char *file, int lineno, int ret)
+static int load_conf_printf(const char *file, int lineno, int ret)
 {
 	if (ret != CONF_RET_OK) {
 		printf("process config file '%s' failed at line %d.", file, lineno);
@@ -224,15 +245,15 @@ int load_conf_printf(const char *file, int lineno, int ret)
 	return 0;
 }

-int load_conf_file(const char *file, struct config_item *items, conf_error_handler handler)
+static int load_conf_file(const char *file, struct config_item *items, conf_error_handler handler)
 {
 	FILE *fp = NULL;
 	char line[MAX_LINE_LEN];
 	char key[MAX_KEY_LEN];
 	char value[MAX_LINE_LEN];
 	int filed_num = 0;
-	int i;
-	int argc;
+	int i = 0;
+	int argc = 0;
 	char *argv[1024];
 	int ret = 0;
 	int call_ret = 0;
@@ -262,6 +283,7 @@ int load_conf_file(const char *file, struct config_item *items, conf_error_handl

 		/* if field format is not key = value, error */
 		if (filed_num != 2) {
+			handler(file, line_no, CONF_RET_BADCONF);
 			goto errout;
 		}

--- a/src/lib/radix.c
+++ b/src/lib/radix.c
@@ -87,7 +87,7 @@ comp_with_mask(unsigned char *addr, unsigned char *dest, unsigned int mask)
 {
 	if (memcmp(addr, dest, mask / 8) == 0) {
 		unsigned int n = mask / 8;
-		unsigned int m = ((~0) << (8 - (mask % 8)));
+		unsigned int m = ((unsigned int)(~0) << (8 - (mask % 8)));

 		if (mask % 8 == 0 || (addr[n] & m) == (dest[n] & m))
 			return (1);
@@ -549,7 +549,7 @@ sanitise_mask(unsigned char *addr, unsigned int masklen, unsigned int maskbits)
 	unsigned int j = masklen % 8;

 	if (j != 0) {
-		addr[i] &= (~0) << (8 - j);
+		addr[i] &= (unsigned int)(~0) << (8 - j);
 		i++;
 	}
 	for (; i < maskbits / 8; i++)
--- a/src/smartdns.c
+++ b/src/smartdns.c
@@ -55,12 +55,12 @@ static int verbose_screen;
 int capget(struct __user_cap_header_struct *header, struct __user_cap_data_struct *cap);
 int capset(struct __user_cap_header_struct *header, struct __user_cap_data_struct *cap);

-int get_uid_gid(int *uid, int *gid)
+static int get_uid_gid(int *uid, int *gid)
 {
 	struct passwd *result = NULL;
 	struct passwd pwd;
 	char *buf = NULL;
-	size_t bufsize;
+	ssize_t bufsize = 0;
 	int ret = -1;

 	if (dns_conf_user[0] == '\0') {
@@ -79,7 +79,7 @@ int get_uid_gid(int *uid, int *gid)

 	ret = getpwnam_r(dns_conf_user, &pwd, buf, bufsize, &result);
 	if (ret != 0) {
-		return -1;
+		goto out;
 	}

 	*uid = result->pw_uid;
@@ -93,14 +93,15 @@ out:
 	return ret;
 }

-int drop_root_privilege(void)
+static int drop_root_privilege(void)
 {
 	struct __user_cap_data_struct cap;
 	struct __user_cap_header_struct header;
 	header.version = _LINUX_CAPABILITY_VERSION;
 	header.pid = 0;
-	int uid;
-	int gid;
+	int uid = 0;
+	int gid = 0;
+	int unused __attribute__((unused)) = 0;

 	if (get_uid_gid(&uid, &gid) != 0) {
 		return -1;
@@ -113,8 +114,8 @@ int drop_root_privilege(void)
 	prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0);
 	cap.effective |= (1 << CAP_NET_RAW | 1 << CAP_NET_ADMIN);
 	cap.permitted |= (1 << CAP_NET_RAW | 1 << CAP_NET_ADMIN);
-	setuid(uid);
-	setgid(gid);
+	unused = setgid(gid);
+	unused = setuid(uid);
 	if (capset(&header, &cap) < 0) {
 		return -1;
 	}
@@ -131,7 +132,7 @@ static void _help(void)
 		"Start smartdns server.\n"
 		"  -f            run forground.\n"
 		"  -c [conf]     config file.\n"
-		"  -p [pid]      pid file path\n"
+		"  -p [pid]      pid file path, '-' means don't create pid file.\n"
 		"  -S            ignore segment fault signal.\n"
 		"  -x            verbose screen.\n"
 		"  -v            dispaly version.\n"
@@ -186,7 +187,7 @@ static int _smartdns_load_from_resolv(void)
 			continue;
 		}

-		if (strncmp(key, "nameserver", MAX_KEY_LEN) != 0) {
+		if (strncmp(key, "nameserver", MAX_KEY_LEN - 1) != 0) {
 			continue;
 		}

@@ -212,14 +213,14 @@ static int _smartdns_load_from_resolv(void)

 static int _smartdns_add_servers(void)
 {
-	int i = 0;
+	unsigned long i = 0;
 	int j = 0;
 	int ret = 0;
 	struct dns_server_groups *group = NULL;
 	struct dns_servers *server = NULL;
 	struct client_dns_server_flags flags;

-	for (i = 0; i < dns_conf_server_num; i++) {
+	for (i = 0; i < (unsigned int)dns_conf_server_num; i++) {
 		memset(&flags, 0, sizeof(flags));
 		switch (dns_conf_servers[i].type) {
 		case DNS_SERVER_UDP: {
@@ -322,15 +323,22 @@ static int _smartdns_destroy_ssl(void)
 	return 0;
 }

-static int _smartdns_init(void)
+static const char *_smartdns_log_path(void)
 {
-	int ret;
 	char *logfile = SMARTDNS_LOG_FILE;

 	if (dns_conf_log_file[0] != 0) {
 		logfile = dns_conf_log_file;
 	}

+	return logfile;
+}
+
+static int _smartdns_init(void)
+{
+	int ret = 0;
+	const char *logfile = _smartdns_log_path();
+
 	ret = tlog_init(logfile, dns_conf_log_size, dns_conf_log_num, 0, 0);
 	if (ret != 0) {
 		tlog(TLOG_ERROR, "start tlog failed.\n");
@@ -340,7 +348,7 @@ static int _smartdns_init(void)
 	tlog_setlogscreen(verbose_screen);
 	tlog_setlevel(dns_conf_log_level);

-	tlog(TLOG_NOTICE, "smartdns starting...(Copyright (C) Nick Peng <pymumu@gmail.com>, build:%s %s)", __DATE__,
+	tlog(TLOG_NOTICE, "smartdns starting...(Copyright (C) Nick Peng <pymumu@gmail.com>, build: %s %s)", __DATE__,
 		 __TIME__);

 	if (_smartdns_init_ssl() != 0) {
@@ -396,10 +404,10 @@ static int _smartdns_run(void)

 static void _smartdns_exit(void)
 {
-	tlog(TLOG_INFO, "smartdns starting exit...");
-	dns_server_exit();
+	tlog(TLOG_INFO, "smartdns exit...");
 	dns_client_exit();
 	fast_ping_exit();
+	dns_server_exit();
 	_smartdns_destroy_ssl();
 	tlog_exit();
 	dns_server_load_exit();
@@ -407,7 +415,7 @@ static void _smartdns_exit(void)

 static void _sig_exit(int signo)
 {
-	tlog(TLOG_INFO, "start stop smartdns");
+	tlog(TLOG_INFO, "stop smartdns by signal %d", signo);
 	dns_server_stop();
 }

@@ -450,7 +458,8 @@ static int sig_num = sizeof(sig_list) / sizeof(int);

 static void _reg_signal(void)
 {
-	struct sigaction act, old;
+	struct sigaction act;
+	struct sigaction old;
 	int i = 0;
 	act.sa_sigaction = _sig_error_exit;
 	sigemptyset(&act.sa_mask);
@@ -461,11 +470,48 @@ static void _reg_signal(void)
 	}
 }

+static int _smartdns_create_logdir(void)
+{
+	int uid = 0;
+	int gid = 0;
+	char logdir[PATH_MAX] = {0};
+	safe_strncpy(logdir, _smartdns_log_path(), PATH_MAX);
+	dirname(logdir);
+
+	if (access(logdir, F_OK) == 0) {
+		return 0;
+	}
+
+	if (mkdir(logdir, 0750) != 0) {
+		if (errno == EEXIST) {
+			return 0;
+		}
+
+		return -1;
+	}
+
+	int unused __attribute__((unused)) = 0;
+
+	if (get_uid_gid(&uid, &gid) != 0) {
+		return -1;
+	}
+
+	chown(logdir, uid, gid);
+	return 0;
+}
+
+static int _smartdns_init_pre(void)
+{
+	_smartdns_create_logdir();
+
+	return 0;
+}
+
 int main(int argc, char *argv[])
 {
-	int ret;
+	int ret = 0;
 	int is_forground = 0;
-	int opt;
+	int opt = 0;
 	char config_file[MAX_LINE_LEN];
 	char pid_file[MAX_LINE_LEN];
 	int signal_ignore = 0;
@@ -476,9 +522,9 @@ int main(int argc, char *argv[])

 	/* patch for Asus router:  unblock all signal*/
 	sigemptyset(&empty_sigblock);
-    sigprocmask(SIG_SETMASK, &empty_sigblock, NULL);
+	sigprocmask(SIG_SETMASK, &empty_sigblock, NULL);

-	while ((opt = getopt(argc, argv, "fhc:p:Svx")) != -1) {
+	while ((opt = getopt(argc, argv, "fhc:p:SvxN:")) != -1) {
 		switch (opt) {
 		case 'f':
 			is_forground = 1;
@@ -499,12 +545,21 @@ int main(int argc, char *argv[])
 			_show_version();
 			return 0;
 			break;
+#ifdef DEBUG
+		case 'N':
+			return dns_packet_debug(optarg);
+#endif
 		case 'h':
 			_help();
 			return 1;
 		}
 	}

+	if (dns_server_load_conf(config_file) != 0) {
+		fprintf(stderr, "load config failed.\n");
+		goto errout;
+	}
+
 	if (is_forground == 0) {
 		if (daemon(0, 0) < 0) {
 			fprintf(stderr, "run daemon process failed, %s\n", strerror(errno));
@@ -516,14 +571,17 @@ int main(int argc, char *argv[])
 		_reg_signal();
 	}

-	if (create_pid_file(pid_file) != 0) {
+	if (strncmp(pid_file, "-", 2) != 0 && create_pid_file(pid_file) != 0) {
 		goto errout;
 	}

 	signal(SIGPIPE, SIG_IGN);
-	if (dns_server_load_conf(config_file) != 0) {
-		fprintf(stderr, "load config failed.\n");
-		goto errout;
+	signal(SIGINT, _sig_exit);
+	signal(SIGTERM, _sig_exit);
+
+	if (_smartdns_init_pre() != 0) {
+		fprintf(stderr, "init failed.\n");
+		return 1;
 	}

 	drop_root_privilege();
@@ -534,8 +592,6 @@ int main(int argc, char *argv[])
 		goto errout;
 	}

-	signal(SIGINT, _sig_exit);
-	signal(SIGTERM, _sig_exit);
 	atexit(_smartdns_exit);

 	return _smartdns_run();
--- a/src/tlog.c
+++ b/src/tlog.c
@@ -79,8 +79,9 @@ struct tlog_log {
    int zip_pid;
    int multi_log;
    int logscreen;
+    int no_write_log;
    int segment_log;
-    unsigned int max_line_size;
+    int max_line_size;

    tlog_output_func output_func;
    void *private_data;
@@ -216,7 +217,6 @@ static int _tlog_mkdir(const char *path)
        }

        if (mkdir(path_c, 0750) != 0) {
-            fprintf(stderr, "create directory %s failed, %s\n", path_c, strerror(errno));
            return -1;
        }

@@ -1091,7 +1091,7 @@ static int _tlog_archive_log(struct tlog_log *log)
    }
 }

-void _tlog_get_log_name_dir(struct tlog_log *log)
+static void _tlog_get_log_name_dir(struct tlog_log *log)
 {
    char log_file[PATH_MAX];
    if (log->fd > 0) {
@@ -1130,6 +1130,10 @@ static int _tlog_write(struct tlog_log *log, const char *buff, int bufflen)
        unused = write(STDOUT_FILENO, buff, bufflen);
    }

+    if (log->no_write_log) {
+        return 0;
+    }
+
    /* if log file size exceeds threshold, start to compress */
    if (log->multi_log && log->fd > 0) {
        log->filesize = lseek(log->fd, 0, SEEK_END);
@@ -1160,7 +1164,15 @@ static int _tlog_write(struct tlog_log *log, const char *buff, int bufflen)

        char logfile[PATH_MAX * 2];
        if (_tlog_mkdir(log->logdir) != 0) {
-            fprintf(stderr, "create log dir %s failed.\n", log->logdir);
+            if (print_errmsg == 0) {
+                return -1;
+            }
+            print_errmsg = 0;
+            fprintf(stderr, "create log dir %s failed, %s\n", log->logdir, strerror(errno));
+            if (errno == EACCES && log->logscreen == 0) {
+                fprintf(stderr, "no permission to write log file, output log to console\n");
+                tlog_logscreen_only(log, 1);
+            }
            return -1;
        }
        snprintf(logfile, sizeof(logfile), "%s/%s", log->logdir, log->logname);
@@ -1574,11 +1586,26 @@ static void _tlog_log_setlogscreen(struct tlog_log *log, int enable)
    log->logscreen = (enable != 0) ? 1 : 0;
 }

+static void _tlog_log_setlogscreen_only(struct tlog_log *log, int enable)
+{
+    if (log == NULL) {
+        return;
+    }
+
+    log->logscreen = (enable != 0) ? 1 : 0;
+    log->no_write_log = (enable != 0) ? 1 : 0;
+}
+
 void tlog_setlogscreen(int enable)
 {
    _tlog_log_setlogscreen(tlog.root, enable);
 }

+void tlog_setlogscreen_only(int enable)
+{
+    _tlog_log_setlogscreen_only(tlog.root, enable);
+}
+
 int tlog_write_log(char *buff, int bufflen)
 {
    if (unlikely(tlog.root == NULL)) {
@@ -1597,6 +1624,15 @@ void tlog_logscreen(tlog_log *log, int enable)
    _tlog_log_setlogscreen(log, enable);
 }

+void tlog_logscreen_only(tlog_log *log, int enable)
+{
+    if (log == NULL) {
+        return;
+    }
+
+    _tlog_log_setlogscreen_only(log, enable);
+}
+
 int tlog_reg_output_func(tlog_log *log, tlog_output_func output)
 {
    if (log == NULL) {
@@ -1830,27 +1866,29 @@ int tlog_init(const char *logfile, int maxlogsize, int maxlogcount, int buffsize
    }
    tlog_reg_output_func(log, _tlog_root_write_log);

+    tlog.root = log;
    ret = pthread_create(&tlog.tid, &attr, _tlog_work, NULL);
    if (ret != 0) {
        fprintf(stderr, "create tlog work thread failed, %s\n", strerror(errno));
        goto errout;
    }

-    tlog.root = log;
    if (flag & TLOG_SUPPORT_FORK) {
        pthread_atfork(&tlog_fork_prepare, &tlog_fork_parent, &tlog_fork_child);
    }
    return 0;
 errout:
-    if (tlog.tid > 0) {
+    if (tlog.tid) {
        void *retval = NULL;
        tlog.run = 0;
        pthread_join(tlog.tid, &retval);
+        tlog.tid = 0;
    }

    pthread_cond_destroy(&tlog.cond);
    pthread_mutex_destroy(&tlog.lock);
    tlog.run = 0;
+    tlog.root = NULL;

    _tlog_close(log, 1);

@@ -1859,7 +1897,7 @@ errout:

 void tlog_exit(void)
 {
-    if (tlog.tid > 0) {
+    if (tlog.tid) {
        void *ret = NULL;
        tlog.run = 0;
        pthread_mutex_lock(&tlog.lock);
--- a/src/tlog.h
+++ b/src/tlog.h
@@ -8,6 +8,7 @@
 #define TLOG_H
 #include <stdarg.h>
 #include <sys/stat.h>
+#include <sys/types.h>

 #ifdef __cplusplus
 #include <functional>
@@ -103,6 +104,9 @@ extern void tlog_set_logfile(const char *logfile);
 /* enalbe log to screen */
 extern void tlog_setlogscreen(int enable);

+/* output log to screen only */
+extern void tlog_setlogscreen_only(int enable);
+
 /* enalbe early log to screen */
 extern void tlog_set_early_printf(int enable);

@@ -183,6 +187,9 @@ extern int tlog_vprintf(tlog_log *log, const char *format, va_list ap);
 /* enalbe log to screen */
 extern void tlog_logscreen(tlog_log *log, int enable);

+/* enalbe log to screen only*/
+extern void tlog_logscreen_only(tlog_log *log, int enable);
+
 /* register output callback */
 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);
--- a/src/util.c
+++ b/src/util.c
@@ -34,11 +34,13 @@
 #include <openssl/crypto.h>
 #include <openssl/ssl.h>
 #include <pthread.h>
+#include <signal.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/prctl.h>
 #include <sys/stat.h>
 #include <sys/statvfs.h>
+#include <sys/time.h>
 #include <sys/types.h>
 #include <time.h>
 #include <unistd.h>
@@ -77,7 +79,9 @@

 #define NETLINK_ALIGN(len) (((len) + 3) & ~(3))

-#define BUFF_SZ 256
+#define BUFF_SZ 1024
+#define PACKET_BUF_SIZE 8192
+#define PACKET_MAGIC 0X11040918

 struct ipset_netlink_attr {
 	unsigned short len;
@@ -108,12 +112,12 @@ char *gethost_by_addr(char *host, int maxsize, struct sockaddr *addr)
 	host[0] = 0;
 	switch (addr_store->ss_family) {
 	case AF_INET: {
-		struct sockaddr_in *addr_in;
+		struct sockaddr_in *addr_in = NULL;
 		addr_in = (struct sockaddr_in *)addr;
 		inet_ntop(AF_INET, &addr_in->sin_addr, host, maxsize);
 	} break;
 	case AF_INET6: {
-		struct sockaddr_in6 *addr_in6;
+		struct sockaddr_in6 *addr_in6 = NULL;
 		addr_in6 = (struct sockaddr_in6 *)addr;
 		if (IN6_IS_ADDR_V4MAPPED(&addr_in6->sin6_addr)) {
 			struct sockaddr_in addr_in4;
@@ -176,14 +180,14 @@ int getsocknet_inet(int fd, struct sockaddr *addr, socklen_t *addr_len)

 	switch (addr_store.ss_family) {
 	case AF_INET: {
-		struct sockaddr_in *addr_in;
+		struct sockaddr_in *addr_in = NULL;
 		addr_in = (struct sockaddr_in *)addr;
 		addr_in->sin_family = AF_INET;
 		*addr_len = sizeof(struct sockaddr_in);
 		memcpy(addr, addr_in, sizeof(struct sockaddr_in));
 	} break;
 	case AF_INET6: {
-		struct sockaddr_in6 *addr_in6;
+		struct sockaddr_in6 *addr_in6 = NULL;
 		addr_in6 = (struct sockaddr_in6 *)addr;
 		if (IN6_IS_ADDR_V4MAPPED(&addr_in6->sin6_addr)) {
 			struct sockaddr_in addr_in4;
@@ -411,7 +415,7 @@ int parse_uri(char *value, char *scheme, char *host, int *port, char *path)
 	};

 	field_len = host_end - process_ptr;
-	if (field_len >= sizeof(host_name)) {
+	if (field_len >= (int)sizeof(host_name)) {
 		return -1;
 	}
 	memcpy(host_name, process_ptr, field_len);
@@ -431,7 +435,7 @@ int parse_uri(char *value, char *scheme, char *host, int *port, char *path)

 int set_fd_nonblock(int fd, int nonblock)
 {
-	int ret;
+	int ret = 0;
 	int flags = fcntl(fd, F_GETFL);

 	if (flags == -1) {
@@ -523,7 +527,7 @@ static int _ipset_socket_init(void)
 	return 0;
 }

-static int _ipset_support_timeout(const char *ipsetname)
+static int _ipset_support_timeout(void)
 {
 	if (dns_conf_ipset_timeout_enable) {
 		return 0;
@@ -535,15 +539,15 @@ static int _ipset_support_timeout(const char *ipsetname)
 static int _ipset_operate(const char *ipsetname, const unsigned char addr[], int addr_len, unsigned long timeout,
 						  int operate)
 {
-	struct nlmsghdr *netlink_head;
-	struct ipset_netlink_msg *netlink_msg;
+	struct nlmsghdr *netlink_head = NULL;
+	struct ipset_netlink_msg *netlink_msg = NULL;
 	struct ipset_netlink_attr *nested[3];
 	char buffer[BUFF_SZ];
-	uint8_t proto;
-	ssize_t rc;
+	uint8_t proto = 0;
+	ssize_t rc = 0;
 	int af = 0;
 	static const struct sockaddr_nl snl = {.nl_family = AF_NETLINK};
-	uint32_t expire;
+	uint32_t expire = 0;

 	if (addr_len != IPV4_ADDR_LEN && addr_len != IPV6_ADDR_LEN) {
 		errno = EINVAL;
@@ -597,7 +601,7 @@ static int _ipset_operate(const char *ipsetname, const unsigned char addr[], int
 					addr);
 	nested[1]->len = (void *)buffer + NETLINK_ALIGN(netlink_head->nlmsg_len) - (void *)nested[1];

-	if (timeout > 0 && _ipset_support_timeout(ipsetname) == 0) {
+	if (timeout > 0 && _ipset_support_timeout() == 0) {
 		expire = htonl(timeout);
 		_ipset_add_attr(netlink_head, IPSET_ATTR_TIMEOUT | NLA_F_NET_BYTEORDER, sizeof(expire), &expire);
 	}
@@ -636,10 +640,11 @@ unsigned char *SSL_SHA256(const unsigned char *d, size_t n, unsigned char *md)
 {
 	static unsigned char m[SHA256_DIGEST_LENGTH];

-	if (md == NULL)
+	if (md == NULL) {
 		md = m;
+	}

-	EVP_MD_CTX* ctx = EVP_MD_CTX_create();
+	EVP_MD_CTX *ctx = EVP_MD_CTX_create();
 	if (ctx == NULL) {
 		return NULL;
 	}
@@ -656,7 +661,7 @@ unsigned char *SSL_SHA256(const unsigned char *d, size_t n, unsigned char *md)
 int SSL_base64_decode(const char *in, unsigned char *out)
 {
 	size_t inlen = strlen(in);
-	int outlen;
+	int outlen = 0;

 	if (inlen == 0) {
 		return 0;
@@ -679,8 +684,8 @@ errout:

 int create_pid_file(const char *pid_file)
 {
-	int fd;
-	int flags;
+	int fd = 0;
+	int flags = 0;
 	char buff[TMP_BUFF_LEN_32];

 	/*  create pid file, and lock this file */
@@ -745,7 +750,7 @@ static __attribute__((unused)) void _pthreads_locking_callback(int mode, int typ

 static __attribute__((unused)) unsigned long _pthreads_thread_id(void)
 {
-	unsigned long ret;
+	unsigned long ret = 0;

 	ret = (unsigned long)pthread_self();
 	return (ret);
@@ -753,16 +758,18 @@ static __attribute__((unused)) unsigned long _pthreads_thread_id(void)

 void SSL_CRYPTO_thread_setup(void)
 {
-	int i;
+	int i = 0;

 	lock_cs = OPENSSL_malloc(CRYPTO_num_locks() * sizeof(pthread_mutex_t));
 	lock_count = OPENSSL_malloc(CRYPTO_num_locks() * sizeof(long));
 	if (!lock_cs || !lock_count) {
 		/* Nothing we can do about this...void function! */
-		if (lock_cs)
+		if (lock_cs) {
 			OPENSSL_free(lock_cs);
-		if (lock_count)
+		}
+		if (lock_count) {
 			OPENSSL_free(lock_count);
+		}
 		return;
 	}
 	for (i = 0; i < CRYPTO_num_locks(); i++) {
@@ -780,7 +787,7 @@ void SSL_CRYPTO_thread_setup(void)

 void SSL_CRYPTO_thread_cleanup(void)
 {
-	int i;
+	int i = 0;

 	CRYPTO_set_locking_callback(NULL);
 	for (i = 0; i < CRYPTO_num_locks(); i++) {
@@ -817,18 +824,20 @@ static int parse_server_name_extension(const char *, size_t, char *, const char
 */
 int parse_tls_header(const char *data, size_t data_len, char *hostname, const char **hostname_ptr)
 {
-	char tls_content_type;
-	char tls_version_major;
-	char tls_version_minor;
+	char tls_content_type = 0;
+	char tls_version_major = 0;
+	char tls_version_minor = 0;
 	size_t pos = TLS_HEADER_LEN;
-	size_t len;
+	size_t len = 0;

-	if (hostname == NULL)
+	if (hostname == NULL) {
 		return -3;
+	}

 	/* Check that our TCP payload is at least large enough for a TLS header */
-	if (data_len < TLS_HEADER_LEN)
+	if (data_len < TLS_HEADER_LEN) {
 		return -1;
+	}

 	/* SSL 2.0 compatible Client Hello
 	 *
@@ -856,8 +865,9 @@ int parse_tls_header(const char *data, size_t data_len, char *hostname, const ch
 	data_len = MIN(data_len, len);

 	/* Check we received entire TLS record length */
-	if (data_len < len)
+	if (data_len < len) {
 		return -1;
+	}

 	/*
 	 * Handshake
@@ -879,20 +889,23 @@ int parse_tls_header(const char *data, size_t data_len, char *hostname, const ch
 	pos += 38;

 	/* Session ID */
-	if (pos + 1 > data_len)
+	if (pos + 1 > data_len) {
 		return -5;
+	}
 	len = (unsigned char)data[pos];
 	pos += 1 + len;

 	/* Cipher Suites */
-	if (pos + 2 > data_len)
+	if (pos + 2 > data_len) {
 		return -5;
+	}
 	len = ((unsigned char)data[pos] << 8) + (unsigned char)data[pos + 1];
 	pos += 2 + len;

 	/* Compression Methods */
-	if (pos + 1 > data_len)
+	if (pos + 1 > data_len) {
 		return -5;
+	}
 	len = (unsigned char)data[pos];
 	pos += 1 + len;

@@ -901,20 +914,22 @@ int parse_tls_header(const char *data, size_t data_len, char *hostname, const ch
 	}

 	/* Extensions */
-	if (pos + 2 > data_len)
+	if (pos + 2 > data_len) {
 		return -5;
+	}
 	len = ((unsigned char)data[pos] << 8) + (unsigned char)data[pos + 1];
 	pos += 2;

-	if (pos + len > data_len)
+	if (pos + len > data_len) {
 		return -5;
+	}
 	return parse_extensions(data + pos, len, hostname, hostname_ptr);
 }

 static int parse_extensions(const char *data, size_t data_len, char *hostname, const char **hostname_ptr)
 {
 	size_t pos = 0;
-	size_t len;
+	size_t len = 0;

 	/* Parse each 4 bytes for the extension header */
 	while (pos + 4 <= data_len) {
@@ -925,15 +940,17 @@ static int parse_extensions(const char *data, size_t data_len, char *hostname, c
 		if (data[pos] == 0x00 && data[pos + 1] == 0x00) {
 			/* There can be only one extension of each type, so we break
 			 * our state and move p to beinnging of the extension here */
-			if (pos + 4 + len > data_len)
+			if (pos + 4 + len > data_len) {
 				return -5;
+			}
 			return parse_server_name_extension(data + pos + 4, len, hostname, hostname_ptr);
 		}
 		pos += 4 + len; /* Advance to the next extension header */
 	}
 	/* Check we ended where we expected to */
-	if (pos != data_len)
+	if (pos != data_len) {
 		return -5;
+	}

 	return -2;
 }
@@ -941,13 +958,14 @@ static int parse_extensions(const char *data, size_t data_len, char *hostname, c
 static int parse_server_name_extension(const char *data, size_t data_len, char *hostname, const char **hostname_ptr)
 {
 	size_t pos = 2; /* skip server name list length */
-	size_t len;
+	size_t len = 0;

 	while (pos + 3 < data_len) {
 		len = ((unsigned char)data[pos + 1] << 8) + (unsigned char)data[pos + 2];

-		if (pos + 3 + len > data_len)
+		if (pos + 3 + len > data_len) {
 			return -5;
+		}

 		switch (data[pos]) { /* name type */
 		case 0x00:           /* host_name */
@@ -964,8 +982,9 @@ static int parse_server_name_extension(const char *data, size_t data_len, char *
 		pos += 3 + len;
 	}
 	/* Check we ended where we expected to */
-	if (pos != data_len)
+	if (pos != data_len) {
 		return -5;
+	}

 	return -2;
 }
@@ -973,8 +992,12 @@ static int parse_server_name_extension(const char *data, size_t data_len, char *
 void get_compiled_time(struct tm *tm)
 {
 	char s_month[5];
-	int month, day, year;
-	int hour, min, sec;
+	int month = 0;
+	int day = 0;
+	int year = 0;
+	int hour = 0;
+	int min = 0;
+	int sec = 0;
 	static const char *month_names = "JanFebMarAprMayJunJulAugSepOctNovDec";

 	sscanf(__DATE__, "%4s %d %d", s_month, &day, &year);
@@ -992,8 +1015,9 @@ void get_compiled_time(struct tm *tm)
 int is_numeric(const char *str)
 {
 	while (*str != '\0') {
-		if (*str < '0' || *str > '9')
+		if (*str < '0' || *str > '9') {
 			return -1;
+		}
 		str++;
 	}
 	return 0;
@@ -1082,9 +1106,9 @@ static _Unwind_Reason_Code unwind_callback(struct _Unwind_Context *context, void
 	if (pc) {
 		if (state->current == state->end) {
 			return _URC_END_OF_STACK;
-		} else {
-			*state->current++ = (void *)(pc);
 		}
+
+		*state->current++ = (void *)(pc);
 	}
 	return _URC_NO_REASON;
 }
@@ -1101,7 +1125,7 @@ void print_stack(void)
 	if (frame_num == 0) {
 		return;
 	}
-	
+
 	tlog(TLOG_FATAL, "Stack:");
 	for (idx = 0; idx < frame_num; ++idx) {
 		const void *addr = buffer[idx];
@@ -1114,13 +1138,31 @@ void print_stack(void)
 		}

 		void *offset = (void *)((char *)(addr) - (char *)(info.dli_fbase));
-		tlog(TLOG_FATAL, "#%.2d: %p %s from %s+%p", idx + 1, addr, symbol, info.dli_fname, offset);
+		tlog(TLOG_FATAL, "#%.2d: %p %s() from %s+%p", idx + 1, addr, symbol, info.dli_fname, offset);
 	}
 }

+void bug_ext(const char *file, int line, const char *func, const char *errfmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, errfmt);
+	tlog_vext(TLOG_FATAL, file, line, func, NULL, errfmt, ap);
+	va_end(ap);
+
+	print_stack();
+	/* trigger BUG */
+	sleep(1);
+	raise(SIGSEGV);
+
+	while (true) {
+		sleep(1);
+	};
+}
+
 int write_file(const char *filename, void *data, int data_len)
 {
-	int fd = open(filename, O_WRONLY|O_CREAT, 0644);
+	int fd = open(filename, O_WRONLY | O_CREAT, 0644);
 	if (fd < 0) {
 		return -1;
 	}
@@ -1138,4 +1180,278 @@ errout:
 	}

 	return -1;
-}
+}
+
+int dns_packet_save(const char *dir, const char *type, const char *from, const void *packet, int packet_len)
+{
+	char *data = NULL;
+	int data_len = 0;
+	char filename[BUFF_SZ];
+	char time_s[BUFF_SZ];
+	int ret = -1;
+
+	struct tm *ptm;
+	struct tm tm;
+	struct timeval tmval;
+	struct stat sb;
+
+	if (stat(dir, &sb) != 0) {
+		mkdir(dir, 0750);
+	}
+
+	if (gettimeofday(&tmval, NULL) != 0) {
+		return -1;
+	}
+
+	ptm = localtime_r(&tmval.tv_sec, &tm);
+	if (ptm == NULL) {
+		return -1;
+	}
+
+	ret = snprintf(time_s, sizeof(time_s) - 1, "%.4d-%.2d-%.2d %.2d:%.2d:%.2d.%.3d", ptm->tm_year + 1900,
+				   ptm->tm_mon + 1, ptm->tm_mday, ptm->tm_hour, ptm->tm_min, ptm->tm_sec, (int)(tmval.tv_usec / 1000));
+	ret = snprintf(filename, sizeof(filename) - 1, "%s/%s-%.4d%.2d%.2d-%.2d%.2d%.2d%.1d.packet", dir, type,
+				   ptm->tm_year + 1900, ptm->tm_mon + 1, ptm->tm_mday, ptm->tm_hour, ptm->tm_min, ptm->tm_sec,
+				   (int)(tmval.tv_usec / 100000));
+
+	data = malloc(PACKET_BUF_SIZE);
+	if (data == NULL) {
+		return -1;
+	}
+
+	data_len = snprintf(data, PACKET_BUF_SIZE,
+						"type: %s\n"
+						"from: %s\n"
+						"time: %s\n"
+						"packet-len: %d\n",
+						type, from, time_s, packet_len);
+	if (data_len <= 0 || data_len >= PACKET_BUF_SIZE) {
+		goto out;
+	}
+
+	data[data_len] = 0;
+	data_len++;
+	uint32_t magic = htonl(PACKET_MAGIC);
+	memcpy(data + data_len, &magic, sizeof(magic));
+	data_len += sizeof(magic);
+	int len_in_h = htonl(packet_len);
+	memcpy(data + data_len, &len_in_h, sizeof(len_in_h));
+	data_len += 4;
+	memcpy(data + data_len, packet, packet_len);
+	data_len += packet_len;
+
+	ret = write_file(filename, data, data_len);
+	if (ret != 0) {
+		goto out;
+	}
+
+	ret = 0;
+out:
+	if (data) {
+		free(data);
+	}
+
+	return ret;
+}
+
+#ifdef DEBUG
+struct _dns_read_packet_info {
+	int data_len;
+	int message_len;
+	char *message;
+	int packet_len;
+	uint8_t *packet;
+	uint8_t data[0];
+};
+
+static struct _dns_read_packet_info *_dns_read_packet_file(const char *packet_file)
+{
+	struct _dns_read_packet_info *info = NULL;
+	int fd = 0;
+	int len = 0;
+	int message_len = 0;
+	uint8_t *ptr = NULL;
+
+	info = malloc(sizeof(struct _dns_read_packet_info) + PACKET_BUF_SIZE);
+	fd = open(packet_file, O_RDONLY);
+	if (fd < 0) {
+		printf("open file %s failed, %s\n", packet_file, strerror(errno));
+		goto errout;
+	}
+
+	len = read(fd, info->data, PACKET_BUF_SIZE);
+	if (len < 0) {
+		printf("read file %s failed, %s\n", packet_file, strerror(errno));
+		goto errout;
+	}
+
+	message_len = strnlen((char *)info->data, PACKET_BUF_SIZE);
+	if (message_len >= 512 || message_len >= len) {
+		printf("invalid packet file, bad message len\n");
+		goto errout;
+	}
+
+	info->message_len = message_len;
+	info->message = (char *)info->data;
+
+	ptr = info->data + message_len + 1;
+	uint32_t magic = 0;
+	if (ptr - (uint8_t *)info + sizeof(magic) >= (size_t)len) {
+		printf("invalid packet file, magic length is invalid.\n");
+		goto errout;
+	}
+
+	memcpy(&magic, ptr, sizeof(magic));
+	if (magic != htonl(PACKET_MAGIC)) {
+		printf("invalid packet file, bad magic\n");
+		goto errout;
+	}
+	ptr += sizeof(magic);
+
+	uint32_t packet_len = 0;
+	if (ptr - info->data + sizeof(packet_len) >= (size_t)len) {
+		printf("invalid packet file, packet length is invalid.\n");
+		goto errout;
+	}
+
+	memcpy(&packet_len, ptr, sizeof(packet_len));
+	packet_len = ntohl(packet_len);
+	ptr += sizeof(packet_len);
+	if (packet_len != (size_t)len - (ptr - info->data)) {
+		printf("invalid packet file, packet length is invalid\n");
+		goto errout;
+	}
+
+	info->packet_len = packet_len;
+	info->packet = ptr;
+
+	close(fd);
+	return info;
+errout:
+
+	if (fd > 0) {
+		close(fd);
+	}
+
+	if (info) {
+		free(info);
+	}
+
+	return NULL;
+}
+
+static int _dns_debug_display(struct dns_packet *packet)
+{
+	int i = 0;
+	int j = 0;
+	int ttl = 0;
+	struct dns_rrs *rrs = NULL;
+	int rr_count = 0;
+	char req_host[MAX_IP_LEN];
+
+	for (j = 1; j < DNS_RRS_END; j++) {
+		rrs = dns_get_rrs_start(packet, j, &rr_count);
+		printf("section: %d\n", j);
+		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};
+				/* get A result */
+				dns_get_A(rrs, name, DNS_MAX_CNAME_LEN, &ttl, addr);
+				req_host[0] = '\0';
+				inet_ntop(AF_INET, addr, req_host, sizeof(req_host));
+				printf("domain: %s A: %s TTL: %d\n", name, req_host, ttl);
+			} break;
+			case DNS_T_AAAA: {
+				unsigned char addr[16];
+				char name[DNS_MAX_CNAME_LEN] = {0};
+				dns_get_AAAA(rrs, name, DNS_MAX_CNAME_LEN, &ttl, addr);
+				req_host[0] = '\0';
+				inet_ntop(AF_INET6, addr, req_host, sizeof(req_host));
+				printf("domain: %s AAAA: %s TTL:%d\n", name, req_host, ttl);
+			} break;
+			case DNS_T_NS: {
+				char cname[DNS_MAX_CNAME_LEN];
+				char name[DNS_MAX_CNAME_LEN] = {0};
+				dns_get_CNAME(rrs, name, DNS_MAX_CNAME_LEN, &ttl, cname, DNS_MAX_CNAME_LEN);
+				printf("domain: %s TTL: %d NS: %s\n", name, ttl, cname);
+			} break;
+			case DNS_T_CNAME: {
+				char cname[DNS_MAX_CNAME_LEN];
+				char name[DNS_MAX_CNAME_LEN] = {0};
+				if (dns_conf_force_no_cname) {
+					continue;
+				}
+
+				dns_get_CNAME(rrs, name, DNS_MAX_CNAME_LEN, &ttl, cname, DNS_MAX_CNAME_LEN);
+				printf("domain: %s TTL: %d CNAME: %s\n", name, ttl, cname);
+			} break;
+			case DNS_T_SOA: {
+				char name[DNS_MAX_CNAME_LEN] = {0};
+				struct dns_soa soa;
+				dns_get_SOA(rrs, name, 128, &ttl, &soa);
+				printf("domain: %s SOA: mname: %s, rname: %s, serial: %d, refresh: %d, retry: %d, expire: "
+					   "%d, minimum: %d",
+					   name, soa.mname, soa.rname, soa.serial, soa.refresh, soa.retry, soa.expire, soa.minimum);
+			} break;
+			default:
+				break;
+			}
+		}
+		printf("\n");
+	}
+
+	return 0;
+}
+
+int dns_packet_debug(const char *packet_file)
+{
+	struct _dns_read_packet_info *info = NULL;
+	char buff[DNS_PACKSIZE];
+
+	tlog_setlogscreen_only(1);
+	tlog_setlevel(TLOG_DEBUG);
+
+	info = _dns_read_packet_file(packet_file);
+	if (info == NULL) {
+		goto errout;
+	}
+
+	const char *send_env = getenv("SMARTDNS_DEBUG_SEND");
+	if (send_env != NULL) {
+		char ip[32];
+		int port = 53;
+		if (parse_ip(send_env, ip, &port) == 0) {
+			int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
+			if (sockfd > 0) {
+				struct sockaddr_in server;
+				server.sin_family = AF_INET;
+				server.sin_port = htons(port);
+				server.sin_addr.s_addr = inet_addr(ip);
+				sendto(sockfd, info->packet, info->packet_len, 0, (struct sockaddr *)&server, sizeof(server));
+				close(sockfd);
+			}
+		}
+	}
+
+	struct dns_packet *packet = (struct dns_packet *)buff;
+	if (dns_decode(packet, DNS_PACKSIZE, info->packet, info->packet_len) != 0) {
+		printf("decode failed.\n");
+		goto errout;
+	}
+
+	_dns_debug_display(packet);
+
+	free(info);
+	return 0;
+
+errout:
+	if (info) {
+		free(info);
+	}
+
+	return -1;
+}
+
+#endif
--- a/src/util.h
+++ b/src/util.h
@@ -45,6 +45,16 @@ extern "C" {
 #define PORT_NOT_DEFINED -1
 #define MAX_IP_LEN 64

+#ifndef BASE_FILE_NAME
+#define BASE_FILE_NAME                                                     \
+  (__builtin_strrchr(__FILE__, '/') ? __builtin_strrchr(__FILE__, '/') + 1 \
+                                    : __FILE__)
+#endif
+#define BUG(format, ...) bug_ext(BASE_FILE_NAME, __LINE__, __func__, format, ##__VA_ARGS__)
+
+void bug_ext(const char *file, int line, const char *func, const char *errfmt, ...)
+	__attribute__((format(printf, 4, 5))) __attribute__((nonnull(4)));
+
 unsigned long get_tick_count(void);

 char *gethost_by_addr(char *host, int maxsize, struct sockaddr *addr);
@@ -116,6 +126,10 @@ void print_stack(void);

 int write_file(const char *filename, void *data, int data_len);

+int dns_packet_save(const char *dir, const char *type, const char *from, const void *packet, int packet_len);
+
+int dns_packet_debug(const char *packet_file);
+
 #ifdef __cplusplus
 }
 #endif /*__cplusplus */
Author	SHA1	Message	Date
Nick Peng	5a2559f064	Update readme	2022-08-06 16:24:33 +08:00
Nick Peng	3605e6ed71	smartdns: support no create pid file.	2022-08-05 22:13:26 +08:00
Nick Peng	6588c9822f	fast_ping: supress error log	2022-08-04 21:40:18 +08:00
honwen.chan	2f1d83cc2c	docker: refine Dockerfile, make cache happy.	2022-08-01 21:58:51 +08:00
Nick Peng	ac042e8bee	dns-debug: support record fail packet for debugging	2022-07-31 15:49:10 +08:00
Nick Peng	ab415f2ee9	feature: support response mode: first-ping, fastest-ip, fastest-response	2022-07-25 22:54:27 +08:00
Nick Peng	d3bbd8edd7	log: set default log path to /var/log/smartdns/ and auto create directory	2022-07-25 22:52:42 +08:00
Nick Peng	9390a49a72	dns_server: make log happy.	2022-07-21 21:45:14 +08:00
Felix Yan	798226ddb3	Correct typos in dns.c	2022-07-17 14:10:00 +08:00
Nick Peng	d223194eff	dns_server: fix crash issue	2022-07-14 22:55:50 +08:00
Nick Peng	a83818c094	code: cleanup lint and extra compile warnings	2022-07-10 10:32:01 +08:00
Nick Peng	4e2161c6fc	conf: optimize badconfig log	2022-07-07 22:49:30 +08:00
Nick Peng	7d62226995	server: some minor fixes	2022-07-05 23:32:22 +08:00
Nick Peng	092b4ede88	dns_server: fix ip number is only one when speed check is none	2022-07-05 00:18:28 +08:00