1 #ifndef _TCP_DCTCP_H
2 #define _TCP_DCTCP_H
3
4 static inline void dctcp_ece_ack_cwr(struct sock *sk, u32 ce_state)
5 {
6 struct tcp_sock *tp = tcp_sk(sk);
7
8 if (ce_state == 1)
9 tp->ecn_flags |= TCP_ECN_DEMAND_CWR;
10 else
11 tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR;
12 }
13
14 /* Minimal DCTP CE state machine:
15 *
16 * S: 0 <- last pkt was non-CE
17 * 1 <- last pkt was CE
18 */
19 static inline void dctcp_ece_ack_update(struct sock *sk, enum tcp_ca_event evt,
20 u32 *prior_rcv_nxt, u32 *ce_state)
21 {
22 u32 new_ce_state = (evt == CA_EVENT_ECN_IS_CE) ? 1 : 0;
23
24 if (*ce_state != new_ce_state) {
25 /* CE state has changed, force an immediate ACK to
26 * reflect the new CE state. If an ACK was delayed,
27 * send that first to reflect the prior CE state.
28 */
29 if (inet_csk(sk)->icsk_ack.pending & ICSK_ACK_TIMER) {
30 dctcp_ece_ack_cwr(sk, *ce_state);
31 __tcp_send_ack(sk, *prior_rcv_nxt);
32 }
33 inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_NOW;
34 }
35 *prior_rcv_nxt = tcp_sk(sk)->rcv_nxt;
36 *ce_state = new_ce_state;
37 dctcp_ece_ack_cwr(sk, new_ce_state);
38 }
39
40 #endif
41
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