| Message ID | 1348323537-30310-4-git-send-email-ncardwell@google.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Neal Cardwell <ncardwell@google.com> Date: Sat, 22 Sep 2012 10:18:57 -0400 > A TCP Fast Open (TFO) passive connection must call both > tcp_check_req() and tcp_validate_incoming() for all incoming ACKs that > are attempting to complete the 3WHS. > > This is needed to parallel all the action that happens for a non-TFO > connection, where for an ACK that is attempting to complete the 3WHS > we call both tcp_check_req() and tcp_validate_incoming(). > > For example, upon receiving the ACK that completes the 3WHS, we need > to call tcp_fast_parse_options() and update ts_recent based on the > incoming timestamp value in the ACK. > > One symptom of the problem with the previous code was that for passive > TFO connections using TCP timestamps, the outgoing TS ecr values > ignored the incoming TS val value on the ACK that completed the 3WHS. > > Signed-off-by: Neal Cardwell <ncardwell@google.com> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index bb32668..36e069a1 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5969,7 +5969,8 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb, if (tcp_check_req(sk, skb, req, NULL, true) == NULL) goto discard; - } else if (!tcp_validate_incoming(sk, skb, th, 0)) + } + if (!tcp_validate_incoming(sk, skb, th, 0)) return 0; /* step 5: check the ACK field */
A TCP Fast Open (TFO) passive connection must call both tcp_check_req() and tcp_validate_incoming() for all incoming ACKs that are attempting to complete the 3WHS. This is needed to parallel all the action that happens for a non-TFO connection, where for an ACK that is attempting to complete the 3WHS we call both tcp_check_req() and tcp_validate_incoming(). For example, upon receiving the ACK that completes the 3WHS, we need to call tcp_fast_parse_options() and update ts_recent based on the incoming timestamp value in the ACK. One symptom of the problem with the previous code was that for passive TFO connections using TCP timestamps, the outgoing TS ecr values ignored the incoming TS val value on the ACK that completed the 3WHS. Signed-off-by: Neal Cardwell <ncardwell@google.com> --- net/ipv4/tcp_input.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)