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#ifndef _NET_TCP_ECN_H_
#define _NET_TCP_ECN_H_ 1
#include <linux/config.h>
#ifdef CONFIG_INET_ECN
#include <net/inet_ecn.h>
#define TCP_HP_BITS (~(TCP_RESERVED_BITS|TCP_FLAG_PSH)|TCP_FLAG_ECE|TCP_FLAG_CWR)
#define TCP_ECN_OK 1
#define TCP_ECN_QUEUE_CWR 2
#define TCP_ECN_DEMAND_CWR 4
static __inline__ void
TCP_ECN_queue_cwr(struct tcp_opt *tp)
{
if (tp->ecn_flags&TCP_ECN_OK)
tp->ecn_flags |= TCP_ECN_QUEUE_CWR;
}
/* Output functions */
static __inline__ void
TCP_ECN_send_synack(struct tcp_opt *tp, struct sk_buff *skb)
{
TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_CWR;
if (!(tp->ecn_flags&TCP_ECN_OK))
TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_ECE;
}
static __inline__ void
TCP_ECN_send_syn(struct tcp_opt *tp, struct sk_buff *skb)
{
tp->ecn_flags = 0;
if (sysctl_tcp_ecn) {
TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ECE|TCPCB_FLAG_CWR;
tp->ecn_flags = TCP_ECN_OK;
}
}
static __inline__ void
TCP_ECN_make_synack(struct open_request *req, struct tcphdr *th)
{
if (req->ecn_ok)
th->ece = 1;
}
static __inline__ void
TCP_ECN_send(struct sock *sk, struct tcp_opt *tp, struct sk_buff *skb, int tcp_header_len)
{
if (tp->ecn_flags & TCP_ECN_OK) {
/* Not-retransmitted data segment: set ECT and inject CWR. */
if (skb->len != tcp_header_len &&
!before(TCP_SKB_CB(skb)->seq, tp->snd_nxt)) {
INET_ECN_xmit(sk);
if (tp->ecn_flags&TCP_ECN_QUEUE_CWR) {
tp->ecn_flags &= ~TCP_ECN_QUEUE_CWR;
skb->h.th->cwr = 1;
}
} else {
/* ACK or retransmitted segment: clear ECT|CE */
INET_ECN_dontxmit(sk);
}
if (tp->ecn_flags & TCP_ECN_DEMAND_CWR)
skb->h.th->ece = 1;
}
}
/* Input functions */
static __inline__ void
TCP_ECN_accept_cwr(struct tcp_opt *tp, struct sk_buff *skb)
{
if (skb->h.th->cwr)
tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR;
}
static __inline__ void
TCP_ECN_check_ce(struct tcp_opt *tp, struct sk_buff *skb)
{
if (tp->ecn_flags&TCP_ECN_OK) {
if (INET_ECN_is_ce(TCP_SKB_CB(skb)->flags))
tp->ecn_flags |= TCP_ECN_DEMAND_CWR;
/* Funny extension: if ECT is not set on a segment,
* it is surely retransmit. It is not in ECN RFC,
* but Linux follows this rule. */
else if (!INET_ECN_is_capable((TCP_SKB_CB(skb)->flags)))
tcp_enter_quickack_mode(tp);
}
}
static __inline__ void
TCP_ECN_rcv_synack(struct tcp_opt *tp, struct tcphdr *th)
{
if ((tp->ecn_flags&TCP_ECN_OK) && (!th->ece || th->cwr))
tp->ecn_flags &= ~TCP_ECN_OK;
}
static __inline__ void
TCP_ECN_rcv_syn(struct tcp_opt *tp, struct tcphdr *th)
{
if ((tp->ecn_flags&TCP_ECN_OK) && (!th->ece || !th->cwr))
tp->ecn_flags &= ~TCP_ECN_OK;
}
static __inline__ int
TCP_ECN_rcv_ecn_echo(struct tcp_opt *tp, struct tcphdr *th)
{
if (th->ece && !th->syn && (tp->ecn_flags&TCP_ECN_OK))
return 1;
return 0;
}
static __inline__ void
TCP_ECN_openreq_child(struct tcp_opt *tp, struct open_request *req)
{
tp->ecn_flags = req->ecn_ok ? TCP_ECN_OK : 0;
}
static __inline__ void
TCP_ECN_create_request(struct open_request *req, struct tcphdr *th)
{
if (sysctl_tcp_ecn && th->ece && th->cwr)
req->ecn_ok = 1;
}
#else
#define TCP_HP_BITS (~(TCP_RESERVED_BITS|TCP_FLAG_PSH))
#define TCP_ECN_send_syn(x...) do { } while (0)
#define TCP_ECN_send_synack(x...) do { } while (0)
#define TCP_ECN_make_synack(x...) do { } while (0)
#define TCP_ECN_send(x...) do { } while (0)
#define TCP_ECN_queue_cwr(x...) do { } while (0)
#define TCP_ECN_accept_cwr(x...) do { } while (0)
#define TCP_ECN_check_ce(x...) do { } while (0)
#define TCP_ECN_rcv_synack(x...) do { } while (0)
#define TCP_ECN_rcv_syn(x...) do { } while (0)
#define TCP_ECN_rcv_ecn_echo(x...) (0)
#define TCP_ECN_openreq_child(x...) do { } while (0)
#define TCP_ECN_create_request(x...) do { } while (0)
#endif
#endif
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