diff --git a/src/linux/net/newip/nip_input.c b/src/linux/net/newip/nip_input.c
index 5ea944392cf80e1c678c5ec93d00f09fb9a6d1b3..64a5e90495edd684f8c90844fe2400a3c6585725 100644
--- a/src/linux/net/newip/nip_input.c
+++ b/src/linux/net/newip/nip_input.c
@@ -44,7 +44,7 @@ static int _nip_update_recv_skb_len(struct sk_buff *skb,
 static int nip_rcv_finish(struct sk_buff *skb)
 {
 	struct net *net = dev_net(skb->dev);
-	void (*edemux)(struct sk_buff *skb);
+	void (*edemux)(struct sk_buff *skb) = NULL;
 
 	/* set /proc/sys/net/ipv4/ip_early_demux to change sysctl_ip_early_demux,
 	 * which is used by ipv4, ipv6 and newip
diff --git a/src/linux/net/newip/nip_output.c b/src/linux/net/newip/nip_output.c
index 6c5642a61850c220342b1de9327dd1f5a0ae11f9..3ede2a062510125a9c9c8a9131b84f1fc9048ae1 100644
--- a/src/linux/net/newip/nip_output.c
+++ b/src/linux/net/newip/nip_output.c
@@ -312,8 +312,7 @@ static int nip_dst_lookup_tail(struct net *net, const struct sock *sk,
 
 	rt = (struct nip_rt_info *)*dst;
 	if (*dst == &net->newip.nip_broadcast_entry->dst) {
-		if (!&fln->saddr)
-			fln->saddr = fln->daddr;
+		fln->saddr = fln->daddr;
 		err = 0;
 	} else {
 		err = nip_route_get_saddr(net, rt, &fln->daddr, &fln->saddr);
diff --git a/src/linux/net/newip/tcp_nip.c b/src/linux/net/newip/tcp_nip.c
index 7c6a02610d801185f2fb21e6b72908736bafd835..ce19f60f7e575225018d2c6e3ec6fd373f46b38d 100644
--- a/src/linux/net/newip/tcp_nip.c
+++ b/src/linux/net/newip/tcp_nip.c
@@ -1108,7 +1108,7 @@ int tcp_nip_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonbloc
 	int copied = 0;
 	u32 *seq;
 	unsigned long used;
-	int err;
+	int err = 0;
 	int target;
 	long timeo;
 	size_t len_tmp = len;
@@ -1381,25 +1381,35 @@ static int tcp_nip_rcv(struct sk_buff *skb)
 	int ret;
 	int dif = skb->skb_iif;
 
-	if (skb->pkt_type != PACKET_HOST)
+	if (skb->pkt_type != PACKET_HOST) {
+		DEBUG("%s unknown pkt-type(%u), drop skb.", __func__, skb->pkt_type);
 		goto discard_it;
+	}
 
-	if (!nip_get_tcp_input_checksum(skb))
+	if (!nip_get_tcp_input_checksum(skb)) {
+		DEBUG("%s checksum fail, drop skb.", __func__);
 		goto discard_it;
+	}
 
 	th = (const struct tcphdr *)skb->data;
 
-	if (unlikely(th->doff < sizeof(struct tcphdr) / TCP_NUM_4))
-		goto bad_packet;
+	if (unlikely(th->doff < sizeof(struct tcphdr) / TCP_NUM_4)) {
+		DEBUG("%s non-four byte alignment, drop skb.", __func__);
+		goto discard_it;
+	}
 
 	sk = __ninet_lookup_skb(&tcp_hashinfo, skb, __tcp_hdrlen(th),
-				th->source, th->dest, dif,
-				&refcounted);
-	if (!sk)
+				th->source, th->dest, dif, &refcounted);
+	if (!sk) {
+		DEBUG("%s: can`t find related sock for skb, will disconnect.", __func__);
 		goto no_tcp_socket;
+	}
 
-	if (sk->sk_state == TCP_TIME_WAIT)
-		goto do_time_wait;
+	if (sk->sk_state == TCP_TIME_WAIT) {
+		/* Handles the SK portion of the interrupt state */
+		DEBUG("%s sk_state is TCP_TIME_WAIT, drop skb.", __func__);
+		goto discard_it;
+	}
 	if (sk->sk_state == TCP_NEW_SYN_RECV) {
 		struct request_sock *req = inet_reqsk(sk);
 		struct sock *nsk;
@@ -1420,11 +1430,12 @@ static int tcp_nip_rcv(struct sk_buff *skb)
 			nsk = tcp_nip_check_req(sk, skb, req);
 		}
 		if (!nsk || nsk == sk) {
-			DEBUG("%s skb info error and create newsk failure!!!", __func__);
+			DEBUG("%s skb info error and create newsk failure, drop skb.", __func__);
 			reqsk_put(req);
 			goto discard_and_relse;
 		}
 		if (tcp_nip_child_process(sk, nsk, skb)) {
+			DEBUG("%s child process fail, drop skb.", __func__);
 			goto discard_and_relse;
 		} else {
 			sock_put(sk);
@@ -1434,8 +1445,10 @@ static int tcp_nip_rcv(struct sk_buff *skb)
 
 	tcp_nip_fill_cb(skb, th);
 
-	if (tcp_filter(sk, skb))
+	if (tcp_filter(sk, skb)) {
+		DEBUG("%s tcp filter fail, drop skb.", __func__);
 		goto discard_and_relse;
+	}
 	th = (const struct tcphdr *)skb->data;
 	skb->dev = NULL;
 
@@ -1453,8 +1466,10 @@ static int tcp_nip_rcv(struct sk_buff *skb)
 	} else {
 		DEBUG("%s: sock locked by user! put packet into backlog",
 		      __func__);
-		if (tcp_nip_add_backlog(sk, skb))
+		if (tcp_nip_add_backlog(sk, skb)) {
+			DEBUG("%s add backlog fail, drop skb.", __func__);
 			goto discard_and_relse;
+		}
 	}
 
 	bh_unlock_sock(sk);
@@ -1465,14 +1480,9 @@ put_and_return:
 	return ret ? -1 : 0;
 
 no_tcp_socket:
-	/* Checksum checked, send reset back */
 	tcp_nip_send_reset(NULL, skb);
-	DEBUG("%s: cannot find related tcp sock for skb", __func__);
-	goto discard_it;
-bad_packet:
 	goto discard_it;
 discard_it:
-	DEBUG("%s: drop tcp newip skb and release it", __func__);
 	kfree_skb(skb);
 	return 0;
 
@@ -1481,9 +1491,6 @@ discard_and_relse:
 	if (refcounted)
 		sock_put(sk);
 	goto discard_it;
-/* Handles the SK portion of the interrupt state */
-do_time_wait:
-	goto discard_it;
 }
 
 static void tcp_nip_early_demux(struct sk_buff *skb)
diff --git a/src/linux/net/newip/tcp_nip_input.c b/src/linux/net/newip/tcp_nip_input.c
index a01dcf1e425758fde8baf00298c45761a7fbe68e..7b2a3c893245d33552763c9818c42838632ec6a1 100644
--- a/src/linux/net/newip/tcp_nip_input.c
+++ b/src/linux/net/newip/tcp_nip_input.c
@@ -429,7 +429,7 @@ static int tcp_nip_clean_rtx_queue(struct sock *sk, ktime_t *skb_snd_tstamp)
 
 	while ((skb = tcp_write_queue_head(sk)) && skb != tcp_nip_send_head(sk)) {
 		struct tcp_skb_cb *scb = TCP_SKB_CB(skb);
-		u32 acked_pcount;
+		u32 acked_pcount = 0;
 
 		if (after(scb->end_seq, tp->snd_una)) {
 			if (tcp_skb_pcount(skb) == 1 || !after(tp->snd_una, scb->seq))
@@ -827,7 +827,7 @@ int _tcp_nip_conn_request(struct request_sock_ops *rsk_ops,
 	/* The best way to do this is to prink the value of user_mss and see if it is 0 */
 	tmp_opt.user_mss  = tp->rx_opt.user_mss;
 	/* Parsing of TCP options in SKB */
-	tcp_nip_parse_options(skb, &tmp_opt, 0, false);
+	tcp_nip_parse_options(skb, &tmp_opt, 0, NULL);
 
 	/* Tstamp_ok indicates the TIMESTAMP seen on the received SYN packet */
 	tmp_opt.tstamp_ok = tmp_opt.saw_tstamp;
diff --git a/src/linux/net/newip/tcp_nip_output.c b/src/linux/net/newip/tcp_nip_output.c
index 15d64bb089906c71183a08d710babfd9a67cbaba..80a69ba065cc43515b9a8cb4132c29e13622024d 100644
--- a/src/linux/net/newip/tcp_nip_output.c
+++ b/src/linux/net/newip/tcp_nip_output.c
@@ -166,19 +166,18 @@ u32 __nip_tcp_select_window(struct sock *sk)
 
 	/* Don't do rounding if we are using window scaling, since the
 	 * scaled window will not line up with the MSS boundary anyway.
+	 * tp->rx_opt.rcv_wscale is always true
 	 */
-	if (tp->rx_opt.rcv_wscale) {
-		window = free_space;
+	window = free_space;
 
-		/* Advertise enough space so that it won't get scaled away.
-		 * Import case: prevent zero window announcement if
-		 * 1<<rcv_wscale > mss.
-		 */
-		window = ALIGN(window, (1 << tp->rx_opt.rcv_wscale));
-		DEBUG("%s wscale(%u) win change [%u to %u], [allowed|free]space=[%u, %u], mss=%u",
-		      __func__, tp->rx_opt.rcv_wscale, free_space, window,
-		      allowed_space, free_space, mss);
-	}
+	/* Advertise enough space so that it won't get scaled away.
+	 * Import case: prevent zero window announcement if
+	 * 1<<rcv_wscale > mss.
+	 */
+	window = ALIGN(window, (1 << tp->rx_opt.rcv_wscale));
+	DEBUG("%s wscale(%u) win change [%u to %u], [allowed|free]space=[%u, %u], mss=%u",
+	      __func__, tp->rx_opt.rcv_wscale, free_space, window,
+	      allowed_space, free_space, mss);
 	return window;
 }
 
diff --git a/src/linux/net/newip/tcp_nip_parameter.c b/src/linux/net/newip/tcp_nip_parameter.c
index dcd42eb13ce8809d676132cfed584a51d09cbfd0..1badd91f3745d4dca480d172f0ff049bd50278de 100644
--- a/src/linux/net/newip/tcp_nip_parameter.c
+++ b/src/linux/net/newip/tcp_nip_parameter.c
@@ -136,6 +136,12 @@ module_param_named(nip_keepalive_time, g_nip_keepalive_time, int, 0644);
 int g_nip_keepalive_intvl = 25;
 module_param_named(nip_keepalive_intvl, g_nip_keepalive_intvl, int, 0644);
 
+/*********************************************************************************************/
+/*                            probe parameters                                               */
+/*********************************************************************************************/
+int g_nip_probe_max = 2000;
+module_param_named(nip_probe_max, g_nip_probe_max, int, 0644);
+
 /*********************************************************************************************/
 /*                            window mode parameters                                         */
 /*********************************************************************************************/
diff --git a/src/linux/net/newip/tcp_nip_parameter.h b/src/linux/net/newip/tcp_nip_parameter.h
index 9d830beaa75730b4b6320d7aa765b19f3552906f..6630f6d77e11569691d9dfef386e0dfffef29ed6 100644
--- a/src/linux/net/newip/tcp_nip_parameter.h
+++ b/src/linux/net/newip/tcp_nip_parameter.h
@@ -76,6 +76,11 @@ extern int g_nip_keepalive_intvl;
 extern bool g_nip_tcp_snd_win_enable;
 extern bool g_nip_tcp_rcv_win_enable;
 
+/*********************************************************************************************/
+/*                            probe parameters                                               */
+/*********************************************************************************************/
+extern int g_nip_probe_max;
+
 /*********************************************************************************************/
 /*                            nip debug parameters                                           */
 /*********************************************************************************************/
@@ -92,7 +97,7 @@ do { \
 
 /* Debugging of packet retransmission after ACK */
 extern int g_ack_retrans_debug;
-	#define RETRANS_DBG(fmt, ...) \
+#define RETRANS_DBG(fmt, ...) \
 do { \
 	if (g_ack_retrans_debug) \
 		pr_crit(fmt, ##__VA_ARGS__); \
diff --git a/src/linux/net/newip/tcp_nip_timer.c b/src/linux/net/newip/tcp_nip_timer.c
index 07aeec22d7273c85426474f6702cc069ffa28a58..aa7f1ca27ec3945decc9f21757c5c7895b1a66bd 100644
--- a/src/linux/net/newip/tcp_nip_timer.c
+++ b/src/linux/net/newip/tcp_nip_timer.c
@@ -181,7 +181,6 @@ void tcp_nip_retransmit_timer(struct sock *sk)
 	inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, icsk->icsk_rto, TCP_RTO_MAX);
 }
 
-#define NIP_MAX_PROBES 2000
 void tcp_nip_probe_timer(struct sock *sk)
 {
 	struct inet_connection_sock *icsk = inet_csk(sk);
@@ -198,11 +197,8 @@ void tcp_nip_probe_timer(struct sock *sk)
 		return;
 	}
 
-#ifdef NIP_MAX_PROBES
-	max_probes = NIP_MAX_PROBES; // 2000 - fix session auto close
-#else
-	max_probes = sock_net(sk)->ipv4.sysctl_tcp_retries2;
-#endif
+	/* default: sock_net(sk)->ipv4.sysctl_tcp_retries2 */
+	max_probes = g_nip_probe_max; /* fix session auto close */
 
 	if (sock_flag(sk, SOCK_DEAD)) {
 		const bool alive = inet_csk_rto_backoff(icsk, TCP_RTO_MAX) < TCP_RTO_MAX;
@@ -224,6 +220,8 @@ abort:		icsk_backoff = icsk->icsk_backoff;
 		      __func__, icsk_probes_out, icsk_backoff, max_probes);
 		tcp_nip_write_err(sk);
 	} else {
+		icsk_backoff = icsk->icsk_backoff;
+		icsk_probes_out = icsk->icsk_probes_out;
 		DEBUG("%s will send probe0, icsk_probes_out=%u, icsk_backoff=%u, max_probes=%u",
 		      __func__, icsk_probes_out, icsk_backoff, max_probes);
 		/* Only send another probe if we didn't close things up. */