dns_server: fix crash issue

code: cleanup lint and extra compile warnings
conf: optimize badconfig log
2022-07-14 22:55:50 +08:00 · 2022-07-10 10:32:01 +08:00 · 2022-07-07 22:49:30 +08:00 · 2022-07-05 23:32:22 +08:00 · 2022-07-05 00:18:28 +08:00
24 changed files with 856 additions and 647 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/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 */
@@ -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;
 	}

@@ -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 +731,7 @@ 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 +742,7 @@ 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 +754,7 @@ 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 +766,7 @@ 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 +778,7 @@ 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 +849,6 @@ 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 +884,7 @@ 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 +899,7 @@ 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 +937,7 @@ 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 +965,7 @@ 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 +998,7 @@ 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 +1155,8 @@ 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 +1179,12 @@ 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 +1254,12 @@ 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 +1319,7 @@ 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 +1395,7 @@ 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 +1409,6 @@ 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 +1439,15 @@ 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 +1456,7 @@ 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 +1495,8 @@ 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 +1552,10 @@ 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 +1601,8 @@ 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 +1650,7 @@ 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 +1670,14 @@ 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);
@@ -1717,13 +1721,13 @@ 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_ERROR, "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;
@@ -1786,7 +1790,7 @@ 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;
 		}
@@ -1802,7 +1806,7 @@ 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 +1822,7 @@ 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 +1844,7 @@ 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 +1934,8 @@ 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 +1988,7 @@ 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 +2083,13 @@ 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 +2119,6 @@ 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 +2131,9 @@ 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 +2174,8 @@ 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;
@@ -2213,7 +2216,7 @@ 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;
 }
@@ -2222,7 +2225,7 @@ int dns_packet_update(unsigned char *data, int size, struct dns_update_param *pa
 void dns_debug(void)
 {
 	unsigned char data[1024];
-	int len;
+	ssize_t len;
 	char buff[4096];

 	int fd = open("dns.bin", O_RDWR);
--- 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
@@ -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 +574,10 @@ 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;

@@ -617,7 +621,7 @@ 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,
+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 +642,7 @@ 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 +658,8 @@ 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 +675,9 @@ 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 +687,7 @@ 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 +705,9 @@ 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 +742,8 @@ 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 +760,9 @@ 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 +787,9 @@ 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 +913,7 @@ 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 +963,7 @@ 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 +1199,8 @@ 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 +1215,8 @@ 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 +1226,7 @@ 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 +1242,28 @@ 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 +1271,16 @@ 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 +1306,7 @@ 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 +1324,7 @@ 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 +1371,20 @@ 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 +1393,7 @@ 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 +1428,8 @@ 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 +1444,6 @@ 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 +1476,8 @@ 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 +1511,7 @@ 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 +1571,17 @@ 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;

@@ -1638,7 +1632,7 @@ 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 +1677,9 @@ 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 +1688,6 @@ 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 +1705,9 @@ errout:
 		close(fd);
 	}

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

@@ -1744,7 +1742,7 @@ 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 +1824,7 @@ 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 +1904,11 @@ 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 +1920,7 @@ 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 +1929,7 @@ 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;
@@ -2037,7 +2035,7 @@ 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;

@@ -2211,8 +2209,7 @@ 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 +2231,7 @@ 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 +2286,6 @@ 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 +2310,7 @@ 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 +2320,11 @@ 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 +2346,16 @@ 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 +2529,7 @@ 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 +2640,7 @@ 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 +2829,7 @@ 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 +2884,7 @@ 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 +2921,12 @@ 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 +2965,7 @@ 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 +2973,7 @@ 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 +3003,7 @@ 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 +3013,7 @@ 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 +3024,13 @@ 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 +3067,8 @@ 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 +3145,8 @@ 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 +3171,7 @@ 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 +3201,8 @@ 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 +3223,33 @@ 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 +3259,13 @@ 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 +3275,8 @@ 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 +3284,14 @@ 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 +3312,17 @@ 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 +3336,9 @@ 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 +3350,8 @@ 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 +3390,22 @@ 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 +3449,7 @@ 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 +3458,7 @@ 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 +3483,7 @@ 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 +3514,7 @@ 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 +3525,11 @@ 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 +3544,11 @@ 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;
@@ -80,7 +80,7 @@ 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;
@@ -249,7 +249,7 @@ 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 +261,7 @@ 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 +455,7 @@ 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 +516,7 @@ 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 +574,7 @@ 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 +619,8 @@ 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 +630,10 @@ 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 +710,7 @@ 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 +762,7 @@ 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 +774,7 @@ 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 +836,8 @@ 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 +910,7 @@ 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];
@@ -1144,8 +1144,8 @@ 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 +1212,7 @@ 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 +1242,7 @@ 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 +1505,7 @@ 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 +1515,13 @@ 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 +1565,7 @@ 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 +1617,7 @@ 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 +1633,7 @@ 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 +1660,13 @@ 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 +1694,7 @@ 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 +1710,7 @@ 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 +1760,7 @@ 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 +1774,7 @@ 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 +1838,12 @@ 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);
 	}

@@ -1917,14 +1917,16 @@ static struct config_item _config_item[] = {

 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 +1934,7 @@ 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 +2004,8 @@ 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 +2034,7 @@ 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();
--- 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) {
@@ -711,6 +710,9 @@ 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 +720,14 @@ 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 +887,7 @@ 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 +936,7 @@ 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 +972,7 @@ 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 +1049,11 @@ 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 +1118,7 @@ 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 +1158,24 @@ 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 +1206,10 @@ 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 +1222,11 @@ 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 +1239,6 @@ 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 +1269,18 @@ 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 +1397,20 @@ 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 +1445,7 @@ 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 +1520,7 @@ 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 +1542,11 @@ 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 +1612,8 @@ 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 +1623,7 @@ 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 +1663,7 @@ 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 +1685,7 @@ 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 +1694,11 @@ 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 +1736,11 @@ 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;
--- 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
@@ -129,7 +129,7 @@ int conf_size(const char *item, void *data, int argc, char *argv[])
 	return 0;
 }

-void conf_getopt_reset(void)
+static void conf_getopt_reset(void)
 {
 	static struct option long_options[] = {{"-", 0, 0, 0}, {0, 0, 0, 0}};
 	int argc = 2;
@@ -144,7 +144,7 @@ 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 +205,9 @@ 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 +221,15 @@ 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 +259,7 @@ 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 = setuid(uid);
+	unused = setgid(gid);
 	if (capset(&header, &cap) < 0) {
 		return -1;
 	}
@@ -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: {
@@ -324,7 +325,7 @@ static int _smartdns_destroy_ssl(void)

 static int _smartdns_init(void)
 {
-	int ret;
+	int ret = 0;
 	char *logfile = SMARTDNS_LOG_FILE;

 	if (dns_conf_log_file[0] != 0) {
@@ -396,10 +397,10 @@ 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 +408,7 @@ 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 +451,8 @@ 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);
@@ -463,9 +465,9 @@ static void _reg_signal(void)

 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;
@@ -476,7 +478,7 @@ 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) {
 		switch (opt) {
@@ -505,6 +507,11 @@ int main(int argc, char *argv[])
 		}
 	}

+	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));
@@ -521,10 +528,8 @@ int main(int argc, char *argv[])
 	}

 	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);

 	drop_root_privilege();

@@ -534,8 +539,6 @@ 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
@@ -80,7 +80,7 @@ struct tlog_log {
    int multi_log;
    int logscreen;
    int segment_log;
-    unsigned int max_line_size;
+    int max_line_size;

    tlog_output_func output_func;
    void *private_data;
@@ -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) {
@@ -1842,10 +1842,11 @@ int tlog_init(const char *logfile, int maxlogsize, int maxlogcount, int buffsize
    }
    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);
@@ -1859,7 +1860,7 @@ 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>
--- a/src/util.c
+++ b/src/util.c
@@ -36,6 +36,7 @@
 #include <pthread.h>
 #include <stdlib.h>
 #include <string.h>
+#include <signal.h>
 #include <sys/prctl.h>
 #include <sys/stat.h>
 #include <sys/statvfs.h>
@@ -77,7 +78,7 @@

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

-#define BUFF_SZ 256
+#define BUFF_SZ 1024

 struct ipset_netlink_attr {
 	unsigned short len;
@@ -108,12 +109,12 @@ 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 +177,14 @@ 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 +412,7 @@ 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 +432,7 @@ 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 +524,7 @@ 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 +536,15 @@ 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 +598,7 @@ 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);
 	}
@@ -636,8 +637,9 @@ 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();
 	if (ctx == NULL) {
@@ -656,7 +658,7 @@ 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 +681,8 @@ 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 +747,7 @@ 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 +755,18 @@ 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 +784,7 @@ 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 +821,20 @@ 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 +862,9 @@ 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 +886,23 @@ 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 +911,22 @@ 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 +937,17 @@ 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 +955,14 @@ 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 +979,9 @@ 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 +989,12 @@ 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 +1012,9 @@ 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 +1103,9 @@ 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 +1122,7 @@ 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];
@@ -1114,10 +1135,28 @@ 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);
@@ -1138,4 +1177,4 @@ errout:
 	}

 	return -1;
-}
+}
--- 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);
Author	SHA1	Message	Date
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