forked from Minki/linux
ffd177dea5
DCTCP has two parts - a new ECN signalling mechanism and the response function to it. The first part can be used by other congestion control for DCTCP-ECN deployed networks. This patch moves that part into a separate tcp_dctcp.h to be used by other congestion control module (like how Yeah uses Vegas algorithmas). For example, BBR is experimenting such ECN signal currently https://tinyurl.com/ietf-102-iccrg-bbr2 Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Yousuk Seung <ysseung@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
41 lines
1.0 KiB
C
41 lines
1.0 KiB
C
#ifndef _TCP_DCTCP_H
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#define _TCP_DCTCP_H
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static inline void dctcp_ece_ack_cwr(struct sock *sk, u32 ce_state)
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{
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struct tcp_sock *tp = tcp_sk(sk);
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if (ce_state == 1)
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tp->ecn_flags |= TCP_ECN_DEMAND_CWR;
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else
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tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR;
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}
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/* Minimal DCTP CE state machine:
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*
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* S: 0 <- last pkt was non-CE
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* 1 <- last pkt was CE
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*/
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static inline void dctcp_ece_ack_update(struct sock *sk, enum tcp_ca_event evt,
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u32 *prior_rcv_nxt, u32 *ce_state)
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{
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u32 new_ce_state = (evt == CA_EVENT_ECN_IS_CE) ? 1 : 0;
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if (*ce_state != new_ce_state) {
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/* CE state has changed, force an immediate ACK to
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* reflect the new CE state. If an ACK was delayed,
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* send that first to reflect the prior CE state.
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*/
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if (inet_csk(sk)->icsk_ack.pending & ICSK_ACK_TIMER) {
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dctcp_ece_ack_cwr(sk, *ce_state);
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__tcp_send_ack(sk, *prior_rcv_nxt);
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}
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inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_NOW;
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}
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*prior_rcv_nxt = tcp_sk(sk)->rcv_nxt;
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*ce_state = new_ce_state;
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dctcp_ece_ack_cwr(sk, new_ce_state);
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}
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#endif
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