Files
linux/net/ipv4/tcp_dctcp.h
Tim Bird 2ed4b46b4f net: Add SPDX ids to some source files
Add SPDX-License-Identifier lines to several source
files under the network sub-directory.  Work on files
in the core, dns_resolver, ipv4, ipv6 and
netfilter sub-dirs.  Remove boilerplate
and license reference text to avoid ambiguity.

Rusty Russell has expressed that his contributions
were intended to be GPL-2.0-or-later.

Signed-off-by: Tim Bird <tim.bird@sony.com>
Link: https://patch.msgid.link/20260305004724.87469-1-tim.bird@sony.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-09 18:32:45 -07:00

42 lines
1.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#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, 0);
}
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