diff --git a/src/dns_client.c b/src/dns_client.c
index 5b7a59b..efb6a4b 100644
--- a/src/dns_client.c
+++ b/src/dns_client.c
@@ -1933,7 +1933,7 @@ static int _dns_client_process_tls(struct dns_server_info *server_info, struct e
 			}
 
 			if (_dns_client_tls_verify(server_info) != 0) {
-				tlog(TLOG_WARN, "peer verify failed.");
+				tlog(TLOG_WARN, "peer %s verify failed.", server_info->ip);
 				goto errout;
 			}
 
diff --git a/src/dns_conf.c b/src/dns_conf.c
index e8f0754..4505962 100644
--- a/src/dns_conf.c
+++ b/src/dns_conf.c
@@ -33,7 +33,7 @@ int dns_conf_prefetch = 0;
 
 /* upstream servers */
 struct dns_servers dns_conf_servers[DNS_MAX_SERVERS];
-char dns_conf_server_name[DNS_MAX_CONF_CNAME_LEN];
+char dns_conf_server_name[DNS_MAX_SERVER_NAME_LEN];
 int dns_conf_server_num;
 
 /* logging */
@@ -350,6 +350,10 @@ 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)) {
+		tlog(TLOG_ERROR, "domain name %s too long", domain);
+		goto errout;
+	}
 	reverse_string(domain_key, domain, len);
 	domain_key[len] = '.';
 	len++;
@@ -407,6 +411,10 @@ static int _config_domain_rule_flag_set(char *domain, unsigned int flag)
 	int len = 0;
 
 	len = strlen(domain);
+	if (len >= sizeof(domain_key)) {
+		tlog(TLOG_ERROR, "domain %s too long", domain);
+		return -1;
+	}
 	reverse_string(domain_key, domain, len);
 	domain_key[len] = '.';
 	len++;
@@ -530,6 +538,11 @@ static int _config_ipset(void *data, int argc, char *argv[])
 
 	/* Get domain */
 	len = end - begin;
+	if (len >= sizeof(domain)) {
+		tlog(TLOG_ERROR, "domain name %s too long", value);
+		goto errout;
+	}
+
 	memcpy(domain, begin, len);
 	domain[len] = '\0';
 
@@ -617,6 +630,12 @@ static int _config_address(void *data, int argc, char *argv[])
 
 	/* get domain */
 	len = end - begin;
+
+	if (len >= sizeof(domain)) {
+		tlog(TLOG_ERROR, "domain name %s too long", value);
+		goto errout;
+	}
+
 	memcpy(domain, begin, len);
 	domain[len] = 0;
 
@@ -775,6 +794,12 @@ static int _config_nameserver(void *data, int argc, char *argv[])
 	}
 
 	len = end - begin;
+
+	if (len >= sizeof(domain)) {
+		tlog(TLOG_ERROR, "domain name %s too long", value);
+		goto errout;
+	}
+
 	memcpy(domain, begin, len);
 	domain[len] = '\0';
 
@@ -983,7 +1008,7 @@ static int _config_log_level(void *data, int argc, char *argv[])
 }
 
 static struct config_item _config_item[] = {
-	CONF_STRING("server-name", (char *)dns_conf_server_name, DNS_MAX_CONF_CNAME_LEN),
+	CONF_STRING("server-name", (char *)dns_conf_server_name, DNS_MAX_SERVER_NAME_LEN),
 	CONF_STRING("bind", dns_conf_server_ip, DNS_MAX_IPLEN),
 	CONF_STRING("bind-tcp", dns_conf_server_tcp_ip, DNS_MAX_IPLEN),
 	CONF_CUSTOM("server", _config_server_udp, NULL),
diff --git a/src/dns_conf.h b/src/dns_conf.h
index f3f8e78..4da8384 100644
--- a/src/dns_conf.h
+++ b/src/dns_conf.h
@@ -11,6 +11,7 @@
 #include "radix.h"
 
 #define DNS_MAX_SERVERS 64
+#define DNS_MAX_SERVER_NAME_LEN 128
 #define DNS_MAX_IPSET_NAMELEN 32
 #define DNS_GROUP_NAME_LEN 32
 #define DNS_NAX_GROUP_NUMBER 16
@@ -21,7 +22,7 @@
 #define DEFAULT_DNS_PORT 53
 #define DEFAULT_DNS_TLS_PORT 853
 #define DEFAULT_DNS_HTTPS_PORT 443
-#define DNS_MAX_CONF_CNAME_LEN 128
+#define DNS_MAX_CONF_CNAME_LEN 256
 #define SMARTDNS_CONF_FILE "/etc/smartdns/smartdns.conf"
 #define SMARTDNS_LOG_FILE "/var/log/smartdns.log"
 #define SMARTDNS_AUDIT_FILE "/var/log/smartdns-audit.log"
@@ -156,7 +157,7 @@ extern char dns_conf_audit_file[DNS_MAX_PATH];
 extern size_t dns_conf_audit_size;
 extern int dns_conf_audit_num;
 
-extern char dns_conf_server_name[DNS_MAX_CONF_CNAME_LEN];
+extern char dns_conf_server_name[DNS_MAX_SERVER_NAME_LEN];
 extern art_tree dns_conf_domain_rule;
 extern struct dns_conf_address_rule dns_conf_address_rule;
 
diff --git a/src/util.c b/src/util.c
index 7c57590..0c005eb 100644
--- a/src/util.c
+++ b/src/util.c
@@ -207,7 +207,7 @@ int parse_uri(char *value, char *scheme, char *host, int *port, char *path)
 		field_len = scheme_end - value;
 		if (scheme) {
 			memcpy(scheme, value, field_len);
-			scheme[field_len + 1] = 0;
+			scheme[field_len] = 0;
 		}
 		process_ptr += field_len + 3;
 	} else {
@@ -226,7 +226,7 @@ int parse_uri(char *value, char *scheme, char *host, int *port, char *path)
 		return -1;
 	}
 	memcpy(host_name, process_ptr, field_len);
-	host_name[field_len + 1] = 0;
+	host_name[field_len] = 0;
 
 	if (parse_ip(host_name, host, port) != 0) {
 		return -1;