Fixes DSACK-based undo when sender is in Open State and an ACK advances snd_una.
Example scenario: - Sender goes into recovery and makes some spurious rtx. - It comes out of recovery and enters into open state. - It sends some more packets, let's say 4. - The receiver sends an ACK for the first two, but this ACK is lost. - The sender receives ack for first two, and DSACK for previous spurious rtx. Signed-off-by: Priyaranjan Jha <priyar...@google.com> Signed-off-by: Yuchung Cheng <ych...@google.com> Signed-off-by: Neal Cardwell <ncardw...@google.com> Acked-by: Yousuk Seung <ysse...@google.com> --- net/ipv4/tcp_input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 7eec3383702b..bf69bfbe593b 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -114,7 +114,7 @@ int sysctl_tcp_invalid_ratelimit __read_mostly = HZ/2; #define FLAG_ACKED (FLAG_DATA_ACKED|FLAG_SYN_ACKED) #define FLAG_NOT_DUP (FLAG_DATA|FLAG_WIN_UPDATE|FLAG_ACKED) -#define FLAG_CA_ALERT (FLAG_DATA_SACKED|FLAG_ECE) +#define FLAG_CA_ALERT (FLAG_DATA_SACKED|FLAG_ECE|FLAG_DSACKING_ACK) #define FLAG_FORWARD_PROGRESS (FLAG_ACKED|FLAG_DATA_SACKED) #define TCP_REMNANT (TCP_FLAG_FIN|TCP_FLAG_URG|TCP_FLAG_SYN|TCP_FLAG_PSH) -- 2.15.0.403.gc27cc4dac6-goog
