diff options
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index a5d01b183cf7..5a4408c55155 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -217,16 +217,25 @@ static inline void TCP_ECN_withdraw_cwr(struct tcp_sock *tp) tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR; } -static inline void TCP_ECN_check_ce(struct tcp_sock *tp, struct sk_buff *skb) +static inline void TCP_ECN_check_ce(struct tcp_sock *tp, const struct sk_buff *skb) { - if (tp->ecn_flags & TCP_ECN_OK) { - if (INET_ECN_is_ce(TCP_SKB_CB(skb)->flags)) - tp->ecn_flags |= TCP_ECN_DEMAND_CWR; + if (!(tp->ecn_flags & TCP_ECN_OK)) + return; + + switch (TCP_SKB_CB(skb)->flags & INET_ECN_MASK) { + case INET_ECN_NOT_ECT: /* Funny extension: if ECT is not set on a segment, - * it is surely retransmit. It is not in ECN RFC, - * but Linux follows this rule. */ - else if (INET_ECN_is_not_ect((TCP_SKB_CB(skb)->flags))) + * and we already seen ECT on a previous segment, + * it is probably a retransmit. + */ + if (tp->ecn_flags & TCP_ECN_SEEN) tcp_enter_quickack_mode((struct sock *)tp); + break; + case INET_ECN_CE: + tp->ecn_flags |= TCP_ECN_DEMAND_CWR; + /* fallinto */ + default: + tp->ecn_flags |= TCP_ECN_SEEN; } } |