net/ipv4/tcp_dctcp.h

   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