xref: /OK3568_Linux_fs/kernel/net/ipv4/tcp_dctcp.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun #ifndef _TCP_DCTCP_H
2*4882a593Smuzhiyun #define _TCP_DCTCP_H
3*4882a593Smuzhiyun 
dctcp_ece_ack_cwr(struct sock * sk,u32 ce_state)4*4882a593Smuzhiyun static inline void dctcp_ece_ack_cwr(struct sock *sk, u32 ce_state)
5*4882a593Smuzhiyun {
6*4882a593Smuzhiyun 	struct tcp_sock *tp = tcp_sk(sk);
7*4882a593Smuzhiyun 
8*4882a593Smuzhiyun 	if (ce_state == 1)
9*4882a593Smuzhiyun 		tp->ecn_flags |= TCP_ECN_DEMAND_CWR;
10*4882a593Smuzhiyun 	else
11*4882a593Smuzhiyun 		tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR;
12*4882a593Smuzhiyun }
13*4882a593Smuzhiyun 
14*4882a593Smuzhiyun /* Minimal DCTP CE state machine:
15*4882a593Smuzhiyun  *
16*4882a593Smuzhiyun  * S:	0 <- last pkt was non-CE
17*4882a593Smuzhiyun  *	1 <- last pkt was CE
18*4882a593Smuzhiyun  */
dctcp_ece_ack_update(struct sock * sk,enum tcp_ca_event evt,u32 * prior_rcv_nxt,u32 * ce_state)19*4882a593Smuzhiyun static inline void dctcp_ece_ack_update(struct sock *sk, enum tcp_ca_event evt,
20*4882a593Smuzhiyun 					u32 *prior_rcv_nxt, u32 *ce_state)
21*4882a593Smuzhiyun {
22*4882a593Smuzhiyun 	u32 new_ce_state = (evt == CA_EVENT_ECN_IS_CE) ? 1 : 0;
23*4882a593Smuzhiyun 
24*4882a593Smuzhiyun 	if (*ce_state != new_ce_state) {
25*4882a593Smuzhiyun 		/* CE state has changed, force an immediate ACK to
26*4882a593Smuzhiyun 		 * reflect the new CE state. If an ACK was delayed,
27*4882a593Smuzhiyun 		 * send that first to reflect the prior CE state.
28*4882a593Smuzhiyun 		 */
29*4882a593Smuzhiyun 		if (inet_csk(sk)->icsk_ack.pending & ICSK_ACK_TIMER) {
30*4882a593Smuzhiyun 			dctcp_ece_ack_cwr(sk, *ce_state);
31*4882a593Smuzhiyun 			__tcp_send_ack(sk, *prior_rcv_nxt);
32*4882a593Smuzhiyun 		}
33*4882a593Smuzhiyun 		inet_csk(sk)->icsk_ack.pending |= ICSK_ACK_NOW;
34*4882a593Smuzhiyun 	}
35*4882a593Smuzhiyun 	*prior_rcv_nxt = tcp_sk(sk)->rcv_nxt;
36*4882a593Smuzhiyun 	*ce_state = new_ce_state;
37*4882a593Smuzhiyun 	dctcp_ece_ack_cwr(sk, new_ce_state);
38*4882a593Smuzhiyun }
39*4882a593Smuzhiyun 
40*4882a593Smuzhiyun #endif
41