net/tcp-fastopen: refactor cookie check logic
Refactor the cookie check logic in tcp_send_syn_data() into a function.
This function will be called else where in later changes.
Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index c55d65f..de67541 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1493,6 +1493,8 @@ struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb,
struct tcp_fastopen_cookie *foc,
struct dst_entry *dst);
void tcp_fastopen_init_key_once(bool publish);
+bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss,
+ struct tcp_fastopen_cookie *cookie);
#define TCP_FASTOPEN_KEY_LENGTH 16
/* Fastopen key context */
diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index f519195..f90e09e 100644
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c
@@ -325,3 +325,24 @@ struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb,
*foc = valid_foc;
return NULL;
}
+
+bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss,
+ struct tcp_fastopen_cookie *cookie)
+{
+ unsigned long last_syn_loss = 0;
+ int syn_loss = 0;
+
+ tcp_fastopen_cache_get(sk, mss, cookie, &syn_loss, &last_syn_loss);
+
+ /* Recurring FO SYN losses: no cookie or data in SYN */
+ if (syn_loss > 1 &&
+ time_before(jiffies, last_syn_loss + (60*HZ << syn_loss))) {
+ cookie->len = -1;
+ return false;
+ }
+ if (sysctl_tcp_fastopen & TFO_CLIENT_NO_COOKIE) {
+ cookie->len = -1;
+ return true;
+ }
+ return cookie->len > 0;
+}
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 9a1a149..671c695 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3267,23 +3267,11 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn)
{
struct tcp_sock *tp = tcp_sk(sk);
struct tcp_fastopen_request *fo = tp->fastopen_req;
- int syn_loss = 0, space, err = 0;
- unsigned long last_syn_loss = 0;
+ int space, err = 0;
struct sk_buff *syn_data;
tp->rx_opt.mss_clamp = tp->advmss; /* If MSS is not cached */
- tcp_fastopen_cache_get(sk, &tp->rx_opt.mss_clamp, &fo->cookie,
- &syn_loss, &last_syn_loss);
- /* Recurring FO SYN losses: revert to regular handshake temporarily */
- if (syn_loss > 1 &&
- time_before(jiffies, last_syn_loss + (60*HZ << syn_loss))) {
- fo->cookie.len = -1;
- goto fallback;
- }
-
- if (sysctl_tcp_fastopen & TFO_CLIENT_NO_COOKIE)
- fo->cookie.len = -1;
- else if (fo->cookie.len <= 0)
+ if (!tcp_fastopen_cookie_check(sk, &tp->rx_opt.mss_clamp, &fo->cookie))
goto fallback;
/* MSS for SYN-data is based on cached MSS and bounded by PMTU and