4 files changed, 17 insertions, 13 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 541f26a67ba2..070aeff1b131 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1510,9 +1510,9 @@ static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
 
         while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
                 offset = seq - TCP_SKB_CB(skb)->seq;
-                if (tcp_hdr(skb)->syn)
+                if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)
                         offset--;
-                if (offset < skb->len || tcp_hdr(skb)->fin) {
+                if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) {
                         *off = offset;
                         return skb;
                 }
@@ -1585,7 +1585,7 @@ int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
                         if (offset + 1 != skb->len)
                                 continue;
                 }
-                if (tcp_hdr(skb)->fin) {
+                if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
                         sk_eat_skb(sk, skb, false);
                         ++seq;
                         break;
@@ -1722,11 +1722,11 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                                 break;
 
                         offset = *seq - TCP_SKB_CB(skb)->seq;
-                        if (tcp_hdr(skb)->syn)
+                        if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)
                                 offset--;
                         if (offset < skb->len)
                                 goto found_ok_skb;
-                        if (tcp_hdr(skb)->fin)
+                        if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
                                 goto found_fin_ok;
                         WARN(!(flags & MSG_PEEK),
                              "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
@@ -1959,7 +1959,7 @@ skip_copy:
                 if (used + offset < skb->len)
                         continue;
 
-                if (tcp_hdr(skb)->fin)
+                if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
                         goto found_fin_ok;
                 if (!(flags & MSG_PEEK)) {
                         sk_eat_skb(sk, skb, copied_early);
@@ -2160,8 +2160,10 @@ void tcp_close(struct sock *sk, long timeout)
          *  reader process may not have drained the data yet!
          */
         while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
-                u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq -
-                          tcp_hdr(skb)->fin;
+                u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq;
+
+                if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
+                        len--;
                 data_was_unread += len;
                 __kfree_skb(skb);
         }
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index f97003ad0af5..8f639a4face9 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4093,7 +4093,7 @@ static void tcp_ofo_queue(struct sock *sk)
                 __skb_unlink(skb, &tp->out_of_order_queue);
                 __skb_queue_tail(&sk->sk_receive_queue, skb);
                 tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
-                if (tcp_hdr(skb)->fin)
+                if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
                         tcp_fin(sk);
         }
 }
@@ -4513,7 +4513,7 @@ restart:
                  * - bloated or contains data before "start" or
                  *   overlaps to the next one.
                  */
-                if (!tcp_hdr(skb)->syn && !tcp_hdr(skb)->fin &&
+                if (!(TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN)) &&
                     (tcp_win_from_space(skb->truesize) > skb->len ||
                      before(TCP_SKB_CB(skb)->seq, start))) {
                         end_of_skbs = false;
@@ -4532,7 +4532,8 @@ restart:
                 /* Decided to skip this, advance start seq. */
                 start = TCP_SKB_CB(skb)->end_seq;
         }
-        if (end_of_skbs || tcp_hdr(skb)->syn || tcp_hdr(skb)->fin)
+        if (end_of_skbs ||
+            (TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN)))
                 return;
 
         while (before(start, end)) {
@@ -4579,8 +4580,7 @@ restart:
                                 skb = tcp_collapse_one(sk, skb, list);
                                 if (!skb ||
                                     skb == tail ||
-                                    tcp_hdr(skb)->syn ||
-                                    tcp_hdr(skb)->fin)
+                                    (TCP_SKB_CB(skb)->tcp_flags & (TCPHDR_SYN | TCPHDR_FIN)))
                                         return;
                         }
                 }
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 7881b96d2b72..006b045716d8 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1638,6 +1638,7 @@ int tcp_v4_rcv(struct sk_buff *skb)
         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
                                     skb->len - th->doff * 4);
         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
+        TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
         TCP_SKB_CB(skb)->tcp_tw_isn = 0;
         TCP_SKB_CB(skb)->ip_dsfield = ipv4_get_dsfield(iph);
         TCP_SKB_CB(skb)->sacked  = 0;
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 1835480336ac..de51a88bec6f 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1415,6 +1415,7 @@ static int tcp_v6_rcv(struct sk_buff *skb)
         TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
                                     skb->len - th->doff*4);
         TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
+        TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
         TCP_SKB_CB(skb)->tcp_tw_isn = 0;
         TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
         TCP_SKB_CB(skb)->sacked = 0;