tcp: improve fastopen icmp handling
If a fast open socket is already accepted by the user, it should
be treated like a connected socket to record the ICMP error in
sk_softerr, so the user can fetch it. Do that in both tcp_v4_err
and tcp_v6_err.
Also refactor the sequence window check to improve readability
(e.g., there were two local variables named 'req').
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Daniel Lee <longinus00@gmail.com>
Signed-off-by: Jerry Chu <hkchu@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 7fa6743..a7a62ce 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -340,7 +340,8 @@
struct sock *sk;
int err;
struct tcp_sock *tp;
- __u32 seq;
+ struct request_sock *fastopen;
+ __u32 seq, snd_una;
struct net *net = dev_net(skb->dev);
sk = inet6_lookup(net, &tcp_hashinfo, &hdr->daddr,
@@ -371,8 +372,11 @@
tp = tcp_sk(sk);
seq = ntohl(th->seq);
+ /* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */
+ fastopen = tp->fastopen_rsk;
+ snd_una = fastopen ? tcp_rsk(fastopen)->snt_isn : tp->snd_una;
if (sk->sk_state != TCP_LISTEN &&
- !between(seq, tp->snd_una, tp->snd_nxt)) {
+ !between(seq, snd_una, tp->snd_nxt)) {
NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
goto out;
}
@@ -436,8 +440,13 @@
goto out;
case TCP_SYN_SENT:
- case TCP_SYN_RECV: /* Cannot happen.
- It can, it SYNs are crossed. --ANK */
+ case TCP_SYN_RECV:
+ /* Only in fast or simultaneous open. If a fast open socket is
+ * is already accepted it is treated as a connected one below.
+ */
+ if (fastopen && fastopen->sk == NULL)
+ break;
+
if (!sock_owned_by_user(sk)) {
sk->sk_err = err;
sk->sk_error_report(sk); /* Wake people up to see the error (see connect in sock.c) */
@@ -1760,6 +1769,7 @@
const struct inet_sock *inet = inet_sk(sp);
const struct tcp_sock *tp = tcp_sk(sp);
const struct inet_connection_sock *icsk = inet_csk(sp);
+ struct fastopen_queue *fastopenq = icsk->icsk_accept_queue.fastopenq;
dest = &sp->sk_v6_daddr;
src = &sp->sk_v6_rcv_saddr;
@@ -1802,7 +1812,9 @@
jiffies_to_clock_t(icsk->icsk_ack.ato),
(icsk->icsk_ack.quick << 1) | icsk->icsk_ack.pingpong,
tp->snd_cwnd,
- tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh
+ sp->sk_state == TCP_LISTEN ?
+ (fastopenq ? fastopenq->max_qlen : 0) :
+ (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
);
}