TCPCT part 1a: add request_values parameter for sending SYNACK

Add optional function parameters associated with sending SYNACK.
These parameters are not needed after sending SYNACK, and are not
used for retransmission.  Avoids extending struct tcp_request_sock,
and avoids allocating kernel memory.

Also affects DCCP as it uses common struct request_sock_ops,
but this parameter is currently reserved for future use.

Signed-off-by: William.Allen.Simpson@gmail.com
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 15 deletions

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index de709091b26d..da6e24416d75 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -461,7 +461,8 @@ out:
 }
 
 
-static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req)
+static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req,
+                              struct request_values *rvp)
 {
         struct inet6_request_sock *treq = inet6_rsk(req);
         struct ipv6_pinfo *np = inet6_sk(sk);
@@ -499,7 +500,7 @@ static int tcp_v6_send_synack(struct sock *sk, struct request_sock *req)
         if ((err = xfrm_lookup(sock_net(sk), &dst, &fl, sk, 0)) < 0)
                 goto done;
 
-        skb = tcp_make_synack(sk, dst, req);
+        skb = tcp_make_synack(sk, dst, req, rvp);
         if (skb) {
                 struct tcphdr *th = tcp_hdr(skb);
 
@@ -1161,13 +1162,13 @@ static struct sock *tcp_v6_hnd_req(struct sock *sk,struct sk_buff *skb)
  */
 static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 {
+        struct tcp_options_received tmp_opt;
+        struct request_sock *req;
         struct inet6_request_sock *treq;
         struct ipv6_pinfo *np = inet6_sk(sk);
-        struct tcp_options_received tmp_opt;
         struct tcp_sock *tp = tcp_sk(sk);
-        struct request_sock *req = NULL;
-        __u32 isn = TCP_SKB_CB(skb)->when;
         struct dst_entry *dst = __sk_dst_get(sk);
+        __u32 isn = TCP_SKB_CB(skb)->when;
 #ifdef CONFIG_SYN_COOKIES
         int want_cookie = 0;
 #else
@@ -1239,23 +1240,19 @@ static int tcp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 
                 isn = tcp_v6_init_sequence(skb);
         }
-
         tcp_rsk(req)->snt_isn = isn;
 
         security_inet_conn_request(sk, skb, req);
 
-        if (tcp_v6_send_synack(sk, req))
-                goto drop;
+        if (tcp_v6_send_synack(sk, req, NULL) || want_cookie)
+                goto drop_and_free;
 
-        if (!want_cookie) {
-                inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
-                return 0;
-        }
+        inet6_csk_reqsk_queue_hash_add(sk, req, TCP_TIMEOUT_INIT);
+        return 0;
 
+drop_and_free:
+        reqsk_free(req);
 drop:
-        if (req)
-                reqsk_free(req);
-
         return 0; /* don't send reset */
 }