tcp: Change return value of tcp_rcv_established()

tcp_rcv_established() returns only one value namely 0. We change the return
value to void (as suggested by David Miller).

After commit 0c24604b (tcp: implement RFC 5961 4.2), we no longer send RSTs in
response to SYNs. We can remove the check and processing on the return value of
tcp_rcv_established().

We also fix jtcp_rcv_established() in tcp_probe.c to match that of
tcp_rcv_established().

Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 12 insertions, 18 deletions

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 6a6a88db462d..b1aa324c5e65 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -371,8 +371,8 @@ extern void tcp_delack_timer_handler(struct sock *sk);
 extern int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg);
 extern int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
                                  const struct tcphdr *th, unsigned int len);
-extern int tcp_rcv_established(struct sock *sk, struct sk_buff *skb,
-                               const struct tcphdr *th, unsigned int len);
+extern void tcp_rcv_established(struct sock *sk, struct sk_buff *skb,
+                                const struct tcphdr *th, unsigned int len);
 extern void tcp_rcv_space_adjust(struct sock *sk);
 extern void tcp_cleanup_rbuf(struct sock *sk, int copied);
 extern int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp);
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 1a84fffe6993..93d7e9de4143 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5049,8 +5049,8 @@ discard:
  *      the rest is checked inline. Fast processing is turned on in
  *      tcp_data_queue when everything is OK.
  */
-int tcp_rcv_established(struct sock *sk, struct sk_buff *skb,
-                        const struct tcphdr *th, unsigned int len)
+void tcp_rcv_established(struct sock *sk, struct sk_buff *skb,
+                         const struct tcphdr *th, unsigned int len)
 {
         struct tcp_sock *tp = tcp_sk(sk);
 
@@ -5127,7 +5127,7 @@ int tcp_rcv_established(struct sock *sk, struct sk_buff *skb,
                                 tcp_ack(sk, skb, 0);
                                 __kfree_skb(skb);
                                 tcp_data_snd_check(sk);
-                                return 0;
+                                return;
                         } else { /* Header too small */
                                 TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_INERRS);
                                 goto discard;
@@ -5220,7 +5220,7 @@ no_ack:
                         if (eaten)
                                 kfree_skb_partial(skb, fragstolen);
                         sk->sk_data_ready(sk, 0);
-                        return 0;
+                        return;
                 }
         }
 
@@ -5236,7 +5236,7 @@ slow_path:
          */
 
         if (!tcp_validate_incoming(sk, skb, th, 1))
-                return 0;
+                return;
 
 step5:
         if (tcp_ack(sk, skb, FLAG_SLOWPATH | FLAG_UPDATE_TS_RECENT) < 0)
@@ -5252,7 +5252,7 @@ step5:
 
         tcp_data_snd_check(sk);
         tcp_ack_snd_check(sk);
-        return 0;
+        return;
 
 csum_error:
         TCP_INC_STATS_BH(sock_net(sk), TCP_MIB_CSUMERRORS);
@@ -5260,7 +5260,6 @@ csum_error:
 
 discard:
         __kfree_skb(skb);
-        return 0;
 }
 EXPORT_SYMBOL(tcp_rcv_established);
 
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 09d45d718973..b14266bb91eb 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1799,10 +1799,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
                                 sk->sk_rx_dst = NULL;
                         }
                 }
-                if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len)) {
-                        rsk = sk;
-                        goto reset;
-                }
+                tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
                 return 0;
         }
 
diff --git a/net/ipv4/tcp_probe.c b/net/ipv4/tcp_probe.c
index 1f6aa543b64e..611beab38a00 100644
--- a/net/ipv4/tcp_probe.c
+++ b/net/ipv4/tcp_probe.c
@@ -122,8 +122,8 @@ static inline int tcp_probe_avail(void)
  * Hook inserted to be called before each receive packet.
  * Note: arguments must match tcp_rcv_established()!
  */
-static int jtcp_rcv_established(struct sock *sk, struct sk_buff *skb,
-                                const struct tcphdr *th, unsigned int len)
+static void jtcp_rcv_established(struct sock *sk, struct sk_buff *skb,
+                                 const struct tcphdr *th, unsigned int len)
 {
         const struct tcp_sock *tp = tcp_sk(sk);
         const struct inet_sock *inet = inet_sk(sk);
@@ -172,7 +172,6 @@ static int jtcp_rcv_established(struct sock *sk, struct sk_buff *skb,
         }
 
         jprobe_return();
-        return 0;
 }
 
 static struct jprobe tcp_jprobe = {
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 5bcfadf09e95..9acdcedf9a14 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1360,8 +1360,7 @@ static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
                         }
                 }
 
-                if (tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len))
-                        goto reset;
+                tcp_rcv_established(sk, skb, tcp_hdr(skb), skb->len);
                 if (opt_skb)
                         goto ipv6_pktoptions;
                 return 0;