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-rw-r--r--net/ipv4/tcp_input.c14
1 files changed, 5 insertions, 9 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index ed11931f340f..d3dfff78fa19 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5872,10 +5872,9 @@ static inline void pr_drop_req(struct request_sock *req, __u16 port, int family)
* TCP ECN negotiation.
*
* Exception: tcp_ca wants ECN. This is required for DCTCP
- * congestion control; it requires setting ECT on all packets,
- * including SYN. We inverse the test in this case: If our
- * local socket wants ECN, but peer only set ece/cwr (but not
- * ECT in IP header) its probably a non-DCTCP aware sender.
+ * congestion control: Linux DCTCP asserts ECT on all packets,
+ * including SYN, which is most optimal solution; however,
+ * others, such as FreeBSD do not.
*/
static void tcp_ecn_create_request(struct request_sock *req,
const struct sk_buff *skb,
@@ -5885,18 +5884,15 @@ static void tcp_ecn_create_request(struct request_sock *req,
const struct tcphdr *th = tcp_hdr(skb);
const struct net *net = sock_net(listen_sk);
bool th_ecn = th->ece && th->cwr;
- bool ect, need_ecn, ecn_ok;
+ bool ect, ecn_ok;
if (!th_ecn)
return;
ect = !INET_ECN_is_not_ect(TCP_SKB_CB(skb)->ip_dsfield);
- need_ecn = tcp_ca_needs_ecn(listen_sk);
ecn_ok = net->ipv4.sysctl_tcp_ecn || dst_feature(dst, RTAX_FEATURE_ECN);
- if (!ect && !need_ecn && ecn_ok)
- inet_rsk(req)->ecn_ok = 1;
- else if (ect && need_ecn)
+ if ((!ect && ecn_ok) || tcp_ca_needs_ecn(listen_sk))
inet_rsk(req)->ecn_ok = 1;
}