diff --git a/examples/check_nip_enable.c b/examples/check_nip_enable.c
index 88bf42197b054e64b9532e2ba2549b790e43ee2c..5a4210f9985ba4dda464e6c598e19bdd274b7fa9 100644
--- a/examples/check_nip_enable.c
+++ b/examples/check_nip_enable.c
@@ -74,7 +74,7 @@ int main(int argc, char **argv)
 {
 	int af_ninet = check_nip_enable();
 
-	if (g_nip_enable)
+	if (af_ninet)
 		printf("Support NewIP.\n\n");
 	else
 		printf("Not support NewIP.\n\n");
diff --git a/examples/nip_addr.c b/examples/nip_addr.c
index 00f5cc6ddeee9258930b465172c14f6a42110926..30eecaeef0c80f5e3d99dbc1190bb6d9fe76101d 100644
--- a/examples/nip_addr.c
+++ b/examples/nip_addr.c
@@ -45,7 +45,7 @@
  * ioctl(fd, SIOGIFINDEX, &ifr);
  * ifr.ifr_ifindex; ===> ifindex
  */
-int32_t nip_add_addr(int32_t ifindex, struct nip_addr *addr, int opt)
+int32_t nip_add_addr(int32_t ifindex, const struct nip_addr *addr, int opt)
 {
 	int fd, ret;
 	struct nip_ifreq ifrn;
@@ -60,7 +60,7 @@ int32_t nip_add_addr(int32_t ifindex, struct nip_addr *addr, int opt)
 
 	ret = ioctl(fd, opt, &ifrn);
 	if (ret < 0 && errno != EEXIST) { // ignore File Exists error
-		printf("cfg newip addr fail, ifindex=%d, opt=%u, ret=%d.\n", ifindex, opt, ret);
+		printf("cfg newip addr fail, ifindex=%d, opt=%d, ret=%d.\n", ifindex, opt, ret);
 		close(fd);
 		return -1;
 	}
@@ -80,6 +80,7 @@ int main(int argc, char **argv_input)
 {
 	int ret;
 	int opt;
+	unsigned int len;
 	int ifindex = 0;
 	char **argv = argv_input;
 	char cmd[ARRAY_LEN];
@@ -87,7 +88,7 @@ int main(int argc, char **argv_input)
 	struct nip_addr addr = {0};
 
 	if (argc != DEMO_INPUT_3) {
-		printf("unsupport addr cfg input, argc=%u.\n", argc);
+		printf("unsupport addr cfg input, argc=%d.\n", argc);
 		cmd_help();
 		return -1;
 	}
@@ -95,7 +96,13 @@ int main(int argc, char **argv_input)
 	/* 配置参数1解析: <netcard-name> */
 	argv++;
 	memset(dev, 0, ARRAY_LEN);
-	ret = sscanf(*argv, "%s", dev);
+
+	len = strlen(*argv);
+	if (!len || len >= (ARRAY_LEN - 1))
+		return -1;
+	memcpy(dev, *argv, len);
+	dev[len + 1] = '\0';
+
 	if (strncmp(dev, "wlan", NAME_WLAN_LEN)) {
 		printf("unsupport addr cfg cmd-1, cmd=%s.\n", dev);
 		cmd_help();
@@ -108,7 +115,13 @@ int main(int argc, char **argv_input)
 	/* 配置参数2解析: { add | del } */
 	argv++;
 	memset(cmd, 0, ARRAY_LEN);
-	ret = sscanf(*argv, "%s", cmd);
+
+	len = strlen(*argv);
+	if (!len || len >= (ARRAY_LEN - 1))
+		return -1;
+	memcpy(cmd, *argv, len);
+	cmd[len + 1] = '\0';
+
 	if (!strncmp(cmd, "add", NAME_WLAN_LEN)) {
 		opt = SIOCSIFADDR;
 	} else if (!strncmp(cmd, "del", NAME_WLAN_LEN)) {
@@ -131,7 +144,7 @@ int main(int argc, char **argv_input)
 	if (ret != 0)
 		return -1;
 
-	printf("%s (ifindex=%u) cfg addr success.\n", dev, ifindex);
+	printf("%s (ifindex=%d) cfg addr success.\n", dev, ifindex);
 	return 0;
 }
 
diff --git a/examples/nip_addr_cfg_demo.c b/examples/nip_addr_cfg_demo.c
index 7915b70cf1d7499e4de84900904c2a9adf1c99ae..983902782cd01348ad5c33fc0c4da2c3d73a9156 100644
--- a/examples/nip_addr_cfg_demo.c
+++ b/examples/nip_addr_cfg_demo.c
@@ -109,7 +109,7 @@ int main(int argc, char **argv)
 	if (ret != 0)
 		return -1;
 
-	printf("%s %s(ifindex=%u) cfg addr success.\n", *argv, NIC_NAME, ifindex);
+	printf("%s %s(ifindex=%d) cfg addr success.\n", *argv, NIC_NAME, ifindex);
 	return 0;
 }
 
diff --git a/examples/nip_lib.c b/examples/nip_lib.c
index 5c84643611d1421f8ce7a4824cfd403d196c08b7..1c679a0a576e562cfa71053e535de00bfa16f7af 100644
--- a/examples/nip_lib.c
+++ b/examples/nip_lib.c
@@ -87,14 +87,14 @@ int nip_addr_fmt(char *addr_str, struct nip_addr *sap, int addrlen_input)
 		} else if (addr_str[i] >= 'a' && addr_str[i] <= 'f') {
 			addr_str[i] = addr_str[i] - STR_FMT_2;
 		} else {
-			printf("Newip addr error: uaddr[%u]=%c.\n", i, addr_str[i]);
+			printf("Newip addr error: uaddr[%d]=%c.\n", i, addr_str[i]);
 			return 1;
 		}
 	}
 
 	first_byte = addr_str[0] << NIP_ADDR_LEN_4;
 	first_byte += addr_str[1];
-	if (first_byte >= 0x00 && first_byte <= ADDR_FIRST_DC)
+	if (first_byte <= ADDR_FIRST_DC)
 		addrlen = NIP_ADDR_LEN_1;
 	else if ((first_byte > ADDR_FIRST_DC && first_byte <= ADDR_FIRST_F0) ||
 		 (first_byte == ADDR_FIRST_FF))
@@ -117,7 +117,7 @@ int nip_addr_fmt(char *addr_str, struct nip_addr *sap, int addrlen_input)
 
 	sap->bitlen = addrlen * NIP_ADDR_LEN_8;
 	printf("*************************************************\n");
-	printf("Newip addr len=%u\n", addrlen);
+	printf("Newip addr len=%d\n", addrlen);
 	for (i = 0; i < addrlen; i++) {
 		sap->nip_addr_field8[i] = addr_str[i * INDEX_2] << INDEX_4;
 		sap->nip_addr_field8[i] += addr_str[i * INDEX_2 + 1];
@@ -131,6 +131,7 @@ int nip_addr_fmt(char *addr_str, struct nip_addr *sap, int addrlen_input)
 int nip_get_addr(char **args, struct nip_addr *addr)
 {
 	int ret;
+	unsigned int len;
 	char *sp = *args;
 	int addrlen_input = 0;
 	__u8 addr_str[INDEX_MAX] = {0};
@@ -141,11 +142,16 @@ int nip_get_addr(char **args, struct nip_addr *addr)
 	}
 
 	if (addrlen_input % ADDR_STR_LEN != 0) {
-		printf("NewIP addr str-len invalid, addrlen_input=%u.\n", addrlen_input);
+		printf("NewIP addr str-len invalid, addrlen_input=%d.\n", addrlen_input);
 		return -1;
 	}
 
-	ret = sscanf(*args, "%s", addr_str);
+	len = strlen(*args);
+	if (!len || len >= (INDEX_MAX - 1))
+		return -1;
+	memcpy(addr_str, *args, len);
+	addr_str[len + 1] = '\0';
+
 	return nip_addr_fmt(addr_str, addr, addrlen_input / ADDR_STR_LEN);
 }
 
diff --git a/examples/nip_route.c b/examples/nip_route.c
index 47f56bdf3eda07c3288a3bc0be3a2918b10d7bfd..2fc0ea7923f640efac4dbc556bb1e08731ea33c4 100644
--- a/examples/nip_route.c
+++ b/examples/nip_route.c
@@ -47,8 +47,8 @@
  * ioctl(fd, SIOGIFINDEX, &ifr);
  * ifr.ifr_ifindex; ===> ifindex
  */
-int nip_route_add(int ifindex, struct nip_addr *dst_addr, struct nip_addr *gateway_addr,
-		  uint8_t gateway_flag, int opt)
+int nip_route_add(int ifindex, const struct nip_addr *dst_addr,
+		  const struct nip_addr *gateway_addr, uint8_t gateway_flag, int opt)
 {
 	int fd, ret;
 	struct nip_rtmsg rt;
@@ -92,9 +92,8 @@ int main(int argc, char **argv_input)
 {
 	int ret;
 	int opt;
+	unsigned int len;
 	int ifindex = 0;
-	uint8_t dst_addr_len;
-	uint8_t gateway_addr_len;
 	uint8_t gateway_flag = 0;
 	char **argv = argv_input;
 	char cmd[ARRAY_LEN];
@@ -103,7 +102,7 @@ int main(int argc, char **argv_input)
 	struct nip_addr gateway_addr = {0};
 
 	if (argc != DEMO_INPUT_3 && argc != DEMO_INPUT_4) {
-		printf("unsupport route cfg input, argc=%u.\n", argc);
+		printf("unsupport route cfg input, argc=%d.\n", argc);
 		cmd_help();
 		return -1;
 	}
@@ -111,7 +110,13 @@ int main(int argc, char **argv_input)
 	/* 配置参数1解析: { add | del } */
 	argv++;
 	memset(cmd, 0, ARRAY_LEN);
-	ret = sscanf(*argv, "%s", cmd);
+
+	len = strlen(*argv);
+	if (!len || len >= (ARRAY_LEN - 1))
+		return -1;
+	memcpy(cmd, *argv, len);
+	cmd[len + 1] = '\0';
+
 	if (!strncmp(cmd, "add", NAME_WLAN_LEN)) {
 		opt = SIOCADDRT;
 	} else if (!strncmp(cmd, "del", NAME_WLAN_LEN)) {
@@ -133,7 +138,13 @@ int main(int argc, char **argv_input)
 	/* 配置参数3解析: <netcard-name> */
 	argv++;
 	memset(dev, 0, ARRAY_LEN);
-	ret = sscanf(*argv, "%s", dev);
+
+	len = strlen(*argv);
+	if (!len || len >= (ARRAY_LEN - 1))
+		return -1;
+	memcpy(dev, *argv, len);
+	dev[len + 1] = '\0';
+
 	if (strncmp(dev, "wlan", NAME_WLAN_LEN)) {
 		printf("unsupport route cfg cmd-3, cmd=%s.\n", dev);
 		cmd_help();
@@ -166,7 +177,7 @@ int main(int argc, char **argv_input)
 		return -1;
 	}
 
-	printf("%s (ifindex=%u) cfg route success.\n", dev, ifindex);
+	printf("%s (ifindex=%d) cfg route success.\n", dev, ifindex);
 	return 0;
 }
 
diff --git a/examples/nip_route_cfg_demo.c b/examples/nip_route_cfg_demo.c
index 8a0d4b613a1d3cc03b7aec60953257bffbe6202d..f17cdfbb74ddcbf19f26f2b0b349025f562ecddb 100644
--- a/examples/nip_route_cfg_demo.c
+++ b/examples/nip_route_cfg_demo.c
@@ -87,8 +87,6 @@ int main(int argc, char **argv)
 	uint8_t server_addr[INDEX_2] = {0xDE, 0x00}; // 2-byte address of the server: 0xDE00
 	uint8_t *dst_addr;
 	uint8_t dst_addr_len;
-	uint8_t *gateway_addr;
-	uint8_t gateway_addr_len;
 
 	if (argc == DEMO_INPUT_1) {
 		if (!strcmp(*(argv + 1), "server")) {
@@ -121,7 +119,7 @@ int main(int argc, char **argv)
 		return -1;
 	}
 
-	printf("%s %s(ifindex=%u) cfg route success.\n", *argv, NIC_NAME, ifindex);
+	printf("%s %s(ifindex=%d) cfg route success.\n", *argv, NIC_NAME, ifindex);
 	return 0;
 }
 
diff --git a/examples/nip_tcp_client_demo.c b/examples/nip_tcp_client_demo.c
index 7a83be9fd47bfb62edb233de6c8dd2331bbcb15c..fac89e656e3d88c97bd4ce74b42bdee052d331d0 100644
--- a/examples/nip_tcp_client_demo.c
+++ b/examples/nip_tcp_client_demo.c
@@ -57,7 +57,6 @@ void *send_recv(void *args)
 	fd_set readfds;
 	struct timeval tv, stTime;
 	struct thread_args *th_args = (struct thread_args *) args;
-	struct sockaddr_nin si_server = th_args->si_server;
 
 	cfd = th_args->cfd;
 	for (int i = 0; i < PKTCNT; i++) {
@@ -86,6 +85,10 @@ void *send_recv(void *args)
 				(void)gettimeofday(&stTime, NULL);
 				ret = sscanf(buf, "%d %d NIP_TCP # %d",
 					     &sendtime_sec, &sendtime_usec, &no);
+				if (ret <= 0) {
+					perror("sscanf");
+					goto END;
+				}
 				printf("Received --%s sock %d success:%6d/%6d/no=%6d\n",
 				       buf, cfd, success, count + 1, no);
 			} else {
@@ -125,7 +128,7 @@ int main(int argc, char **argv)
 		perror("connect");
 		return -1;
 	}
-	printf("connect success, addr=0x%02x%02x, port=%u\n",
+	printf("connect success, addr=0x%02x%02x, port=%d\n",
 	       si_server.sin_addr.nip_addr_field8[INDEX_0],
 	       si_server.sin_addr.nip_addr_field8[INDEX_1], TCP_SERVER_PORT);
 
diff --git a/examples/nip_tcp_server_demo.c b/examples/nip_tcp_server_demo.c
index b692e3afae4850d0c921ed66e7e09eebd8fceaca..77433c857493defcbb227cdc185eb34251ca86ac 100644
--- a/examples/nip_tcp_server_demo.c
+++ b/examples/nip_tcp_server_demo.c
@@ -95,7 +95,7 @@ int main(int argc, char **argv)
 		perror("bind");
 		goto END;
 	}
-	printf("bind success, addr=0x%02x%02x, port=%u\n",
+	printf("bind success, addr=0x%02x%02x, port=%d\n",
 	       si_local.sin_addr.nip_addr_field8[INDEX_0],
 	       si_local.sin_addr.nip_addr_field8[INDEX_1], TCP_SERVER_PORT);
 
diff --git a/examples/nip_udp_server_demo.c b/examples/nip_udp_server_demo.c
index 07fc327dc9b5b7f6c3e690a1fe14c32ec57fbf97..f84af5c293002a14b1a3d058919f3617ee13ce97 100644
--- a/examples/nip_udp_server_demo.c
+++ b/examples/nip_udp_server_demo.c
@@ -50,7 +50,7 @@ void *recv_send(void *args)
 	int fd, ret, recv_num;
 	int count = 0;
 	socklen_t slen;
-	struct sockaddr_nin si_local, si_remote;
+	struct sockaddr_nin si_remote;
 
 	memcpy(&fd, args, sizeof(int));
 	while (count < PKTCNT) {
@@ -105,7 +105,7 @@ int main(int argc, char **argv)
 		goto END;
 	}
 
-	printf("bind success, addr=0x%02x%02x, port=%u\n",
+	printf("bind success, addr=0x%02x%02x, port=%d\n",
 	       si_local.sin_addr.nip_addr_field8[INDEX_0],
 	       si_local.sin_addr.nip_addr_field8[INDEX_1], UDP_SERVER_PORT);
 
diff --git a/src/common/nip_checksum.c b/src/common/nip_checksum.c
index b99d527a671ff783c65a7544e0816c8a596ba8e5..98cadf8a4c0b3d286bfead03960afb33c967aab9 100644
--- a/src/common/nip_checksum.c
+++ b/src/common/nip_checksum.c
@@ -33,7 +33,7 @@
 
 #define USHORT_PAYLOAD 16
 #define NIP_CHECKSUM_UINT8_PAYLOAD 8
-unsigned int _nip_check_sum(unsigned char *data, unsigned short data_len)
+unsigned int _nip_check_sum(const unsigned char *data, unsigned short data_len)
 {
 	unsigned int i = 0, sum = 0;
 
diff --git a/src/common/nip_hdr.h b/src/common/nip_hdr.h
index 6b2855b3f788d0d2de40906754a6ea0af403945c..3c99a9691761bca05774a5c6486d4bc6c59e6e18 100644
--- a/src/common/nip_hdr.h
+++ b/src/common/nip_hdr.h
@@ -225,7 +225,7 @@ void nip_hdr_comm_encap(struct nip_hdr_encap *head);
 void nip_update_total_len(struct nip_hdr_encap *head, unsigned short total_len);
 
 /* Note: a function call requires its own byte order conversion.(niph->total_len) */
-int nip_hdr_parse(unsigned char *buf, unsigned int buf_len, struct nip_hdr_decap *niph);
+int nip_hdr_parse(unsigned char *rcv_buf, unsigned int buf_len, struct nip_hdr_decap *niph);
 
 /* The length of the packet header is obtained according to the packet type,
  * source ADDRESS, and destination address.
diff --git a/src/common/nip_hdr_decap.c b/src/common/nip_hdr_decap.c
index 02f93eccee06838515deb4ef874495da42ff6d7e..99408c14b787a6211f6e55047c4a60bf9c672fdb 100644
--- a/src/common/nip_hdr_decap.c
+++ b/src/common/nip_hdr_decap.c
@@ -53,7 +53,7 @@ static int _get_nip_hdr_bitmap(unsigned char *buf,
 }
 
 /* Must carry the current field */
-static int _get_nip_hdr_ttl(unsigned char *buf,
+static int _get_nip_hdr_ttl(const unsigned char *buf,
 			    unsigned char bitmap,
 			    struct nip_hdr_decap *niph)
 {
@@ -70,7 +70,7 @@ static int _get_nip_hdr_ttl(unsigned char *buf,
 /* Communication between devices of the same version may not carry packet Header length,
  * but communication between devices of different versions must carry packet header length
  */
-static int _get_nip_hdr_len(unsigned char *buf,
+static int _get_nip_hdr_len(const unsigned char *buf,
 			    unsigned char bitmap,
 			    struct nip_hdr_decap *niph)
 {
@@ -90,7 +90,7 @@ static int _get_nip_hdr_len(unsigned char *buf,
 }
 
 /* Must carry the current field */
-static int _get_nip_hdr_nexthdr(unsigned char *buf,
+static int _get_nip_hdr_nexthdr(const unsigned char *buf,
 				unsigned char bitmap,
 				struct nip_hdr_decap *niph)
 {
@@ -260,7 +260,6 @@ static int nip_hdr_check(struct nip_hdr_decap *niph)
 int nip_hdr_parse(unsigned char *rcv_buf, unsigned int buf_len, struct nip_hdr_decap *niph)
 {
 	int i = 0;
-	int len;
 	int ret;
 	unsigned char *buf = rcv_buf;
 	unsigned char bitmap[BITMAP_MAX] = {0};
@@ -276,7 +275,8 @@ int nip_hdr_parse(unsigned char *rcv_buf, unsigned int buf_len, struct nip_hdr_d
 	while (i < num) {
 		if (i >= FACTORY_NUM_MAX)
 			break;
-		len = hdr_parse_factory[i](buf, bitmap[i], niph);
+		int len = hdr_parse_factory[i](buf, bitmap[i], niph);
+
 		if (len < 0)
 			return len;
 
diff --git a/src/linux/net/newip/af_ninet.c b/src/linux/net/newip/af_ninet.c
index b193f9f0142cd34ef3a8d742c35102c8474a3163..480e7c2d20ca80c4e0a1626133097be6c4376e7e 100644
--- a/src/linux/net/newip/af_ninet.c
+++ b/src/linux/net/newip/af_ninet.c
@@ -119,8 +119,6 @@ static int ninet_create(struct net *net, struct socket *sock, int protocol,
 	if (err)
 		goto out_rcu_unlock;
 
-	err = -EPERM;
-
 	sock->ops = answer->ops;
 	answer_prot = answer->prot;
 	answer_flags = answer->flags;
diff --git a/src/linux/net/newip/ninet_hashtables.c b/src/linux/net/newip/ninet_hashtables.c
index 5dfea0222d63b7b65c6fbc26209f9714694b61ea..bceb191ebabbb33f184698d0974557bcd9a0b792 100644
--- a/src/linux/net/newip/ninet_hashtables.c
+++ b/src/linux/net/newip/ninet_hashtables.c
@@ -347,10 +347,12 @@ static struct sock *ninet_lhash2_lookup(struct net *net,
 {
 	struct inet_connection_sock *icsk;
 	struct sock *sk, *result = NULL;
-	int score, hiscore = 0, matches = 0, reuseport = 0;
+	int hiscore = 0, matches = 0, reuseport = 0;
 	u32 phash = 0;
 
 	inet_lhash2_for_each_icsk_rcu(icsk, &ilb2->head) {
+		int score;
+
 		sk = (struct sock *)icsk;
 		score = nip_tcp_compute_score(sk, net, hnum, daddr, dif, sdif);
 		if (score > hiscore) {
diff --git a/src/linux/net/newip/nip_addrconf.c b/src/linux/net/newip/nip_addrconf.c
index 56dc3cf404527879cd3140f9238eec98336e312b..90d7ecc6d8792e0f8c3ff97d026696c9242671d2 100644
--- a/src/linux/net/newip/nip_addrconf.c
+++ b/src/linux/net/newip/nip_addrconf.c
@@ -48,7 +48,7 @@ static struct hlist_head ninet_addr_lst[NIN_ADDR_HSIZE];
 static DEFINE_SPINLOCK(addrconf_hash_lock);
 
 static bool nip_chk_same_addr(struct net *net, const struct nip_addr *addr,
-			      struct net_device *dev);
+			      const struct net_device *dev);
 static int nip_get_firstaddr(const struct net_device *dev,
 			     struct nip_addr *addr);
 static int nip_addrconf_ifdown(struct net_device *dev, bool unregister);
@@ -251,8 +251,6 @@ static int ninet_addr_add(struct net *net, int ifindex,
 	struct ninet_dev *idev;
 	struct net_device *dev;
 	unsigned long timeout;
-	clock_t expires;
-	u32 flags;
 	__u32 ifa_flags_tmp = ifa_flags;
 	__u32 valid_lft_tmp = valid_lft;
 
@@ -271,14 +269,10 @@ static int ninet_addr_add(struct net *net, int ifindex,
 		return PTR_ERR(idev);
 
 	timeout = addrconf_timeout_fixup(valid_lft_tmp, HZ);
-	if (addrconf_finite_timeout(timeout)) {
-		expires = jiffies_to_clock_t(timeout * HZ);
+	if (addrconf_finite_timeout(timeout))
 		valid_lft_tmp = timeout;
-	} else {
-		expires = 0;
-		flags = 0;
+	else
 		ifa_flags_tmp |= IFA_F_PERMANENT;
-	}
 
 	timeout = addrconf_timeout_fixup(preferred_lft, HZ);
 	if (addrconf_finite_timeout(timeout)) {
@@ -448,7 +442,7 @@ int nip_addrconf_del_ifaddr(struct net *net, void __user *arg)
 }
 
 static bool nip_chk_same_addr(struct net *net, const struct nip_addr *addr,
-			      struct net_device *dev)
+			      const struct net_device *dev)
 {
 	unsigned int hash = ninet_addr_hash(addr);
 	struct ninet_ifaddr *ifp;
@@ -863,7 +857,6 @@ out:
 void nip_addr_to_str(const struct nip_addr *addr, unsigned char *buf, int buf_len)
 {
 	int i;
-	int len = 0;
 	int total_len = 0;
 	int addr_num = addr->bitlen / NIP_ADDR_BIT_LEN_8;
 
@@ -872,7 +865,8 @@ void nip_addr_to_str(const struct nip_addr *addr, unsigned char *buf, int buf_le
 
 	total_len = sprintf(buf, "%s", "0x");
 	for (i = 0; (i < addr_num) && (total_len < buf_len); i++) {
-		len = sprintf(buf + total_len, "%02x", addr->nip_addr_field8[i]);
+		int len = sprintf(buf + total_len, "%02x", addr->nip_addr_field8[i]);
+
 		if (len <= 0)
 			break;
 		total_len += len;
diff --git a/src/linux/net/newip/nip_output.c b/src/linux/net/newip/nip_output.c
index 3ede2a062510125a9c9c8a9131b84f1fc9048ae1..3338fe3aa8b5d224eef0c3e54c868a5fd3b04a63 100644
--- a/src/linux/net/newip/nip_output.c
+++ b/src/linux/net/newip/nip_output.c
@@ -57,9 +57,7 @@ int nip_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 	struct nip_addr *nexthop;
 	struct neighbour *neigh;
 	int ret = 0;
-	int res;
 	struct net_device *dev = skb_dst(skb)->dev;
-	bool is_v6gw = false;
 
 	skb->protocol = htons(ETH_P_NEWIP);
 	skb->dev = dev;
@@ -73,7 +71,8 @@ int nip_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 	if (unlikely(!neigh))
 		neigh = __neigh_create(&nnd_tbl, nexthop, dev, false);
 	if (!IS_ERR(neigh)) {
-		res = neigh_output(neigh, skb, is_v6gw);
+		int res = neigh_output(neigh, skb, false);
+
 		rcu_read_unlock_bh();
 		return res;
 	}
diff --git a/src/linux/net/newip/nndisc.c b/src/linux/net/newip/nndisc.c
index a46e4f2123541e93c16f4e9c991c88f8cd304746..e2404c3ab41cc7de5e2a4e11e524a1cac4804fee 100644
--- a/src/linux/net/newip/nndisc.c
+++ b/src/linux/net/newip/nndisc.c
@@ -63,7 +63,7 @@
 static void nndisc_solicit(struct neighbour *neigh, struct sk_buff *skb);
 
 static u32 nndisc_hash(const void *pkey,
-		       const struct net_device *dev, __u32 *fhash_rnd);
+		       const struct net_device *dev, __u32 *hash_rnd);
 static bool nndisc_key_eq(const struct neighbour *neigh, const void *pkey);
 static int nndisc_constructor(struct neighbour *neigh);
 
@@ -142,9 +142,9 @@ static u32 nndisc_hash(const void *pkey,
 	return nndisc_hashfn(pkey, dev, hash_rnd);
 }
 
-static bool nndisc_key_eq(const struct neighbour *n, const void *pkey)
+static bool nndisc_key_eq(const struct neighbour *neigh, const void *pkey)
 {
-	return neigh_key_eq800(n, pkey);
+	return neigh_key_eq800(neigh, pkey);
 }
 
 static int nndisc_constructor(struct neighbour *neigh)
@@ -217,7 +217,7 @@ unsigned short nip_get_nndisc_send_checksum(struct sk_buff *skb,
 }
 
 bool nip_get_nndisc_rcv_checksum(struct sk_buff *skb,
-				 u_char *transport_tail)
+				 const u_char *transport_tail)
 {
 	struct nip_pseudo_header nph = {0};
 	unsigned short check_len = (unsigned short)(transport_tail - (skb_transport_header(skb)));
diff --git a/src/linux/net/newip/route.c b/src/linux/net/newip/route.c
index 3c4f40712a47864fa02a1b28605bb37186ce1857..a7acfd35f3c3189b800f5bb1f24873b9fc17b991 100644
--- a/src/linux/net/newip/route.c
+++ b/src/linux/net/newip/route.c
@@ -212,7 +212,7 @@ static struct nip_rt_info *nip_rt_pcpu_alloc(struct nip_rt_info *rt)
 
 static struct nip_rt_info *nip_rt_make_pcpu_route(struct nip_rt_info *rt)
 {
-	struct nip_rt_info *pcpu_rt, *prev, **p;
+	struct nip_rt_info *pcpu_rt, *prev;
 
 	pcpu_rt = nip_rt_pcpu_alloc(rt);
 	if (!pcpu_rt) {
@@ -224,7 +224,8 @@ static struct nip_rt_info *nip_rt_make_pcpu_route(struct nip_rt_info *rt)
 
 	rcu_read_lock_bh();
 	if (rt->rt_pcpu) {
-		p = this_cpu_ptr(rt->rt_pcpu);
+		struct nip_rt_info **p = this_cpu_ptr(rt->rt_pcpu);
+
 		prev = cmpxchg(p, NULL, pcpu_rt);
 		if (prev) {
 			/* If someone did it before us, return prev instead */
diff --git a/src/linux/net/newip/tcp_nip.c b/src/linux/net/newip/tcp_nip.c
index ce19f60f7e575225018d2c6e3ec6fd373f46b38d..922ff08dc1c2c4d25e08f9e372407e39c1a4b228 100644
--- a/src/linux/net/newip/tcp_nip.c
+++ b/src/linux/net/newip/tcp_nip.c
@@ -1739,7 +1739,6 @@ void tcp_nip_exit(void)
 #define LOG_PRINT_MAX_LEN 256
 void nip_dbg(const char *fmt, ...)
 {
-	u32 pos;
 	char str[LOG_PRINT_MAX_LEN];
 	va_list args;
 	s32 ret;
@@ -1748,7 +1747,6 @@ void nip_dbg(const char *fmt, ...)
 		return;
 
 	memset(str, 0, sizeof(str));
-	pos = strlen(str);
 	(void)memset(&args, 0, sizeof(va_list));
 	va_start(args, fmt);
 	ret = vsnprintf(str, sizeof(str), fmt, args) + 1;
diff --git a/src/linux/net/newip/tcp_nip_output.c b/src/linux/net/newip/tcp_nip_output.c
index 80a69ba065cc43515b9a8cb4132c29e13622024d..7ef8b7bd986f87908223c73a4ce6fb9867da7a57 100644
--- a/src/linux/net/newip/tcp_nip_output.c
+++ b/src/linux/net/newip/tcp_nip_output.c
@@ -342,11 +342,11 @@ static __u16 tcp_nip_advertise_mss(struct sock *sk)
 	struct tcp_sock *tp = tcp_sk(sk);
 	const struct dst_entry *dst = __sk_dst_get(sk);
 	int mss = tp->advmss;
-	int nip_hdr_len;
-	int nip_mss;
 	u32 mtu;
 
 	if (dst) {
+		int nip_hdr_len;
+		int nip_mss;
 		unsigned int metric = dst_metric_advmss(dst);
 
 		if (metric < mss) {
@@ -359,7 +359,6 @@ static __u16 tcp_nip_advertise_mss(struct sock *sk)
 					      &sk->sk_nip_daddr);
 		nip_hdr_len = nip_hdr_len == 0 ? NIP_HDR_MAX : nip_hdr_len;
 		nip_mss = mtu - nip_hdr_len - sizeof(struct tcphdr);
-
 		if (nip_mss > mss) {
 			mss = nip_mss;
 			tp->advmss = mss;
@@ -837,7 +836,7 @@ struct sk_buff *tcp_nip_make_synack(const struct sock *sk, struct dst_entry *dst
 int __nip_send_synack(struct request_sock *req, struct sk_buff *skb)
 {
 	struct inet_request_sock *ireq = inet_rsk(req); /* 连接请求块 */
-	int err = -EFAULT;
+	int err;
 	int csummode = CHECKSUM_NONE;
 	struct nip_addr *saddr, *daddr;
 	struct nip_hdr_encap head = {0};
diff --git a/src/linux/net/newip/udp.c b/src/linux/net/newip/udp.c
index 1b4f3fb49c2d4ac38e6f061d78e99b411d0e0628..44d6e0b055c406a65941022e20c2bb24e6e6b7e4 100644
--- a/src/linux/net/newip/udp.c
+++ b/src/linux/net/newip/udp.c
@@ -73,7 +73,6 @@ static int nip_udp_compute_score(struct sock *sk, struct net *net,
 				 const struct nip_addr *daddr, unsigned short hnum,
 				 int dif, int sdif)
 {
-	bool dev_match;
 	int score = 0;
 	struct inet_sock *inet;
 
@@ -112,8 +111,8 @@ static int nip_udp_compute_score(struct sock *sk, struct net *net,
 
 	/* Check the dev index */
 	if (sk->sk_bound_dev_if) {
-		dev_match = dif == sk->sk_bound_dev_if ||
-			    sdif == sk->sk_bound_dev_if;
+		bool dev_match = dif == sk->sk_bound_dev_if || sdif == sk->sk_bound_dev_if;
+
 		if (!dev_match)
 			return -1;
 		score++;
@@ -135,12 +134,11 @@ static struct sock *nip_udp_lib_lookup2(struct net *net,
 {
 	struct sock *sk;
 	struct sock *result = NULL;
-	int score, badness;
+	int badness = -1;
 
-	badness = -1;
 	udp_portaddr_for_each_entry_rcu(sk, &hslot2->head) {
-		score = nip_udp_compute_score(sk, net, saddr, sport, daddr,
-					      hnum, dif, sdif);
+		int score = nip_udp_compute_score(sk, net, saddr, sport, daddr, hnum, dif, sdif);
+
 		if (score > badness) {
 			result = sk;
 			badness = score;
@@ -226,8 +224,8 @@ int nip_udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 		    int noblock, int flags, int *addr_len)
 {
 	struct sk_buff *skb;
-	unsigned int ulen, copied, datalen;
-	int peeking, off;
+	unsigned int ulen, copied;
+	int peeking, off, datalen;
 	int err;
 
 	off = sk_peek_offset(sk, flags);
@@ -355,6 +353,13 @@ int nip_udp_output(struct sock *sk, struct msghdr *msg, size_t len)
 	int err = 0;
 	struct inet_sock *inet;
 
+	if (!sin) {
+		/* Currently, udp socket Connect function is not implemented.
+		 * The destination address and port must be directly provided by Sendto
+		 */
+		return -EDESTADDRREQ;
+	}
+
 	if (sin->sin_family != AF_NINET) {
 		DEBUG("%s: sin_family false.", __func__);
 		return -EAFNOSUPPORT;
@@ -365,16 +370,9 @@ int nip_udp_output(struct sock *sk, struct msghdr *msg, size_t len)
 	}
 
 	inet = inet_sk(sk);
-	if (sin) {
-		/* Destination address, port (network order) must be specified when sendto */
-		dport = sin->sin_port;
-		fln.daddr = sin->sin_addr;
-	} else {
-		/* Currently, udp socket Connect function is not implemented.
-		 * The destination address and port must be directly provided by Sendto
-		 */
-		return -EDESTADDRREQ;
-	}
+	/* Destination address, port (network order) must be specified when sendto */
+	dport = sin->sin_port;
+	fln.daddr = sin->sin_addr;
 	sport = htons(inet->inet_num);
 
 	/* Check the dev index */