Merge branch 'tcp-fastopen-ipv6'

Yuchung Cheng says:

====================
tcp: IPv6 support for fastopen server

This patch series add IPv6 support for fastopen server. To minimize
code duplication in IPv4 and IPv6, the current v4 only code is
refactored and common code is moved into net/ipv4/tcp_fastopen.c.

Also the current code uses a different function from
tcp_v4_send_synack() to send the first SYN-ACK in fastopen.
The new code eliminates this separate function by refactoring the
child-socket and syn-ack creation code.  After these refactoring
in the first four patches, we can easily add the fastopen code in
IPv6 by changing corresponding IPv6 functions.

Note Fast Open client already supports IPv6. This patch is for
the server-side (passive open) IPv6 support only.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 22 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 694711a140d4..3d61c52bdf79 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -627,7 +627,7 @@ static unsigned int tcp_synack_options(struct sock *sk,
 		if (unlikely(!ireq->tstamp_ok))
 			remaining -= TCPOLEN_SACKPERM_ALIGNED;
 	}
-	if (foc != NULL) {
+	if (foc != NULL && foc->len >= 0) {
 		u32 need = TCPOLEN_EXP_FASTOPEN_BASE + foc->len;
 		need = (need + 3) & ~3U;  /* Align to 32 bits */
 		if (remaining >= need) {
@@ -2803,27 +2803,6 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 	if (tp->rx_opt.user_mss && tp->rx_opt.user_mss < mss)
 		mss = tp->rx_opt.user_mss;
 
-	if (req->rcv_wnd == 0) { /* ignored for retransmitted syns */
-		__u8 rcv_wscale;
-		/* Set this up on the first call only */
-		req->window_clamp = tp->window_clamp ? : dst_metric(dst, RTAX_WINDOW);
-
-		/* limit the window selection if the user enforce a smaller rx buffer */
-		if (sk->sk_userlocks & SOCK_RCVBUF_LOCK &&
-		    (req->window_clamp > tcp_full_space(sk) || req->window_clamp == 0))
-			req->window_clamp = tcp_full_space(sk);
-
-		/* tcp_full_space because it is guaranteed to be the first packet */
-		tcp_select_initial_window(tcp_full_space(sk),
-			mss - (ireq->tstamp_ok ? TCPOLEN_TSTAMP_ALIGNED : 0),
-			&req->rcv_wnd,
-			&req->window_clamp,
-			ireq->wscale_ok,
-			&rcv_wscale,
-			dst_metric(dst, RTAX_INITRWND));
-		ireq->rcv_wscale = rcv_wscale;
-	}
-
 	memset(&opts, 0, sizeof(opts));
 #ifdef CONFIG_SYN_COOKIES
 	if (unlikely(req->cookie_ts))