Commit 31aa6503 authored by Yuchung Cheng's avatar Yuchung Cheng Committed by Alexei Starovoitov
Browse files

bpf: correctly set initial window on active Fast Open sender 



The existing BPF TCP initial congestion window (TCP_BPF_IW) does not
to work on (active) Fast Open sender. This is because it changes the
(initial) window only if data_segs_out is zero -- but data_segs_out
is also incremented on SYN-data.  This patch fixes the issue by
proerly accounting for SYN-data additionally.

Fixes: fc747810 ("bpf: Adds support for setting initial cwnd")
Signed-off-by: default avatarYuchung Cheng <ycheng@google.com>
Reviewed-by: default avatarNeal Cardwell <ncardwell@google.com>
Acked-by: default avatarLawrence Brakmo <brakmo@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent d972f3dc

net/core/filter.c

+1 −1
Original line number Diff line number Diff line
@@ -4203,7 +4203,7 @@ BPF_CALL_5(bpf_setsockopt, struct bpf_sock_ops_kern *, bpf_sock, 
			/* Only some options are supported */

			switch (optname) {

			case TCP_BPF_IW:

				if (val <= 0 || tp->data_segs_out > 0)

				if (val <= 0 || tp->data_segs_out > tp->syn_data)

					ret = -EINVAL;

				else

					tp->snd_cwnd = val;