mirror of
https://github.com/torvalds/linux.git
synced 2025-11-04 02:30:34 +02:00
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>
40 lines
1 KiB
C
40 lines
1 KiB
C
#ifndef _TCP_DCTCP_H
|
|
#define _TCP_DCTCP_H
|
|
|
|
static inline void dctcp_ece_ack_cwr(struct sock *sk, u32 ce_state)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
|
|
if (ce_state == 1)
|
|
tp->ecn_flags |= TCP_ECN_DEMAND_CWR;
|
|
else
|
|
tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR;
|
|
}
|
|
|
|
/* Minimal DCTP CE state machine:
|
|
*
|
|
* S: 0 <- last pkt was non-CE
|
|
* 1 <- last pkt was CE
|
|
*/
|
|
static inline void dctcp_ece_ack_update(struct sock *sk, enum tcp_ca_event evt,
|
|
u32 *prior_rcv_nxt, u32 *ce_state)
|
|
{
|
|
u32 new_ce_state = (evt == CA_EVENT_ECN_IS_CE) ? 1 : 0;
|
|
|
|
if (*ce_state != new_ce_state) {
|
|
/* CE state has changed, force an immediate ACK to
|
|
* reflect the new CE state. If an ACK was delayed,
|
|
* send that first to reflect the prior CE state.
|
|
*/
|
|
if (inet_csk(sk)->icsk_ack.pending & ICSK_ACK_TIMER) {
|
|
dctcp_ece_ack_cwr(sk, *ce_state);
|
|
__tcp_send_ack(sk, *prior_rcv_nxt);
|
|
}
|
|
inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_NOW;
|
|
}
|
|
*prior_rcv_nxt = tcp_sk(sk)->rcv_nxt;
|
|
*ce_state = new_ce_state;
|
|
dctcp_ece_ack_cwr(sk, new_ce_state);
|
|
}
|
|
|
|
#endif
|