diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index a34e60e..e20be33 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -173,10 +173,10 @@
 					   struct request_sock *req,
 					   struct dst_entry *dst)
 {
-	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct sock *child;
 
-	child = tp->af_specific->syn_recv_sock(sk, skb, req, dst);
+	child = icsk->icsk_af_ops->syn_recv_sock(sk, skb, req, dst);
 	if (child)
 		inet_csk_reqsk_queue_add(sk, req, child);
 	else
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index ef98b14..eacfe6a 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1696,8 +1696,8 @@
 	int err = 0;
 
 	if (level != SOL_TCP)
-		return tp->af_specific->setsockopt(sk, level, optname,
-						   optval, optlen);
+		return icsk->icsk_af_ops->setsockopt(sk, level, optname,
+						     optval, optlen);
 
 	/* This is a string value all the others are int's */
 	if (optname == TCP_CONGESTION) {
@@ -1939,8 +1939,8 @@
 	int val, len;
 
 	if (level != SOL_TCP)
-		return tp->af_specific->getsockopt(sk, level, optname,
-						   optval, optlen);
+		return icsk->icsk_af_ops->getsockopt(sk, level, optname,
+						     optval, optlen);
 
 	if (get_user(len, optlen))
 		return -EFAULT;
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index bf2e230..7de6184 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4071,8 +4071,10 @@
 		mb();
 		tcp_set_state(sk, TCP_ESTABLISHED);
 
+		icsk = inet_csk(sk);
+
 		/* Make sure socket is routed, for correct metrics.  */
-		tp->af_specific->rebuild_header(sk);
+		icsk->icsk_af_ops->rebuild_header(sk);
 
 		tcp_init_metrics(sk);
 
@@ -4098,8 +4100,6 @@
 			sk_wake_async(sk, 0, POLL_OUT);
 		}
 
-		icsk = inet_csk(sk);
-
 		if (sk->sk_write_pending ||
 		    icsk->icsk_accept_queue.rskq_defer_accept ||
 		    icsk->icsk_ack.pingpong) {
@@ -4220,6 +4220,7 @@
 			  struct tcphdr *th, unsigned len)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
+	struct inet_connection_sock *icsk = inet_csk(sk);
 	int queued = 0;
 
 	tp->rx_opt.saw_tstamp = 0;
@@ -4236,7 +4237,7 @@
 			goto discard;
 
 		if(th->syn) {
-			if(tp->af_specific->conn_request(sk, skb) < 0)
+			if (icsk->icsk_af_ops->conn_request(sk, skb) < 0)
 				return 1;
 
 			/* Now we have several options: In theory there is 
@@ -4349,7 +4350,7 @@
 				/* Make sure socket is routed, for
 				 * correct metrics.
 				 */
-				tp->af_specific->rebuild_header(sk);
+				icsk->icsk_af_ops->rebuild_header(sk);
 
 				tcp_init_metrics(sk);
 
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 2aa19c8..704cf21 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -86,8 +86,7 @@
 /* Socket used for sending RSTs */
 static struct socket *tcp_socket;
 
-void tcp_v4_send_check(struct sock *sk, struct tcphdr *th, int len,
-		       struct sk_buff *skb);
+void tcp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb);
 
 struct inet_hashinfo __cacheline_aligned tcp_hashinfo = {
 	.lhash_lock	= RW_LOCK_UNLOCKED,
@@ -645,10 +644,10 @@
 }
 
 /* This routine computes an IPv4 TCP checksum. */
-void tcp_v4_send_check(struct sock *sk, struct tcphdr *th, int len,
-		       struct sk_buff *skb)
+void tcp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb)
 {
 	struct inet_sock *inet = inet_sk(sk);
+	struct tcphdr *th = skb->h.th;
 
 	if (skb->ip_summed == CHECKSUM_HW) {
 		th->check = ~tcp_v4_check(th, len, inet->saddr, inet->daddr, 0);
@@ -1383,7 +1382,7 @@
 	return 0;
 }
 
-struct tcp_func ipv4_specific = {
+struct inet_connection_sock_af_ops ipv4_specific = {
 	.queue_xmit	=	ip_queue_xmit,
 	.send_check	=	tcp_v4_send_check,
 	.rebuild_header	=	inet_sk_rebuild_header,
@@ -1434,7 +1433,7 @@
 	sk->sk_write_space = sk_stream_write_space;
 	sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
 
-	tp->af_specific = &ipv4_specific;
+	icsk->icsk_af_ops = &ipv4_specific;
 
 	sk->sk_sndbuf = sysctl_tcp_wmem[1];
 	sk->sk_rcvbuf = sysctl_tcp_rmem[1];
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 1b66a2a..9c02968 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -274,18 +274,18 @@
 void tcp_time_wait(struct sock *sk, int state, int timeo)
 {
 	struct inet_timewait_sock *tw = NULL;
+	const struct inet_connection_sock *icsk = inet_csk(sk);
 	const struct tcp_sock *tp = tcp_sk(sk);
 	int recycle_ok = 0;
 
 	if (tcp_death_row.sysctl_tw_recycle && tp->rx_opt.ts_recent_stamp)
-		recycle_ok = tp->af_specific->remember_stamp(sk);
+		recycle_ok = icsk->icsk_af_ops->remember_stamp(sk);
 
 	if (tcp_death_row.tw_count < tcp_death_row.sysctl_max_tw_buckets)
 		tw = inet_twsk_alloc(sk, state);
 
 	if (tw != NULL) {
 		struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw);
-		const struct inet_connection_sock *icsk = inet_csk(sk);
 		const int rto = (icsk->icsk_rto << 2) - (icsk->icsk_rto >> 1);
 
 		tw->tw_rcv_wscale	= tp->rx_opt.rcv_wscale;
@@ -456,7 +456,6 @@
 			   struct request_sock **prev)
 {
 	struct tcphdr *th = skb->h.th;
-	struct tcp_sock *tp = tcp_sk(sk);
 	u32 flg = tcp_flag_word(th) & (TCP_FLAG_RST|TCP_FLAG_SYN|TCP_FLAG_ACK);
 	int paws_reject = 0;
 	struct tcp_options_received tmp_opt;
@@ -613,7 +612,8 @@
 		 * ESTABLISHED STATE. If it will be dropped after
 		 * socket is created, wait for troubles.
 		 */
-		child = tp->af_specific->syn_recv_sock(sk, skb, req, NULL);
+		child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb,
+								 req, NULL);
 		if (child == NULL)
 			goto listen_overflow;
 
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index b7325e0..af1946c 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -371,7 +371,7 @@
 		TCP_ECN_send(sk, tp, skb, tcp_header_size);
 	}
 
-	tp->af_specific->send_check(sk, th, skb->len, skb);
+	icsk->icsk_af_ops->send_check(sk, skb->len, skb);
 
 	if (likely(tcb->flags & TCPCB_FLAG_ACK))
 		tcp_event_ack_sent(sk, tcp_skb_pcount(skb));
@@ -381,7 +381,7 @@
 
 	TCP_INC_STATS(TCP_MIB_OUTSEGS);
 
-	err = tp->af_specific->queue_xmit(skb, 0);
+	err = icsk->icsk_af_ops->queue_xmit(skb, 0);
 	if (unlikely(err <= 0))
 		return err;
 
@@ -638,12 +638,11 @@
 unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
-	int mss_now;
-
 	/* Calculate base mss without TCP options:
 	   It is MMS_S - sizeof(tcphdr) of rfc1122
 	 */
-	mss_now = pmtu - tp->af_specific->net_header_len - sizeof(struct tcphdr);
+	int mss_now = (pmtu - inet_csk(sk)->icsk_af_ops->net_header_len -
+		       sizeof(struct tcphdr));
 
 	/* Clamp it (mss_clamp does not include tcp options) */
 	if (mss_now > tp->rx_opt.mss_clamp)
@@ -705,9 +704,9 @@
 	xmit_size_goal = mss_now;
 
 	if (doing_tso) {
-		xmit_size_goal = 65535 -
-			tp->af_specific->net_header_len -
-			tp->ext_header_len - tp->tcp_header_len;
+		xmit_size_goal = (65535 -
+				  inet_csk(sk)->icsk_af_ops->net_header_len -
+				  tp->ext_header_len - tp->tcp_header_len);
 
 		if (tp->max_window &&
 		    (xmit_size_goal > (tp->max_window >> 1)))
@@ -1422,7 +1421,7 @@
 	   (sysctl_tcp_retrans_collapse != 0))
 		tcp_retrans_try_collapse(sk, skb, cur_mss);
 
-	if(tp->af_specific->rebuild_header(sk))
+	if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk))
 		return -EHOSTUNREACH; /* Routing failure or similar. */
 
 	/* Some Solaris stacks overoptimize and ignore the FIN on a