1 files changed, 126 insertions, 0 deletions
diff --git a/include/net/tcp_ecn.h b/include/net/tcp_ecn.h
new file mode 100644
index 000000000000..dc1456389a97
--- /dev/null
+++ b/include/net/tcp_ecn.h
@@ -0,0 +1,126 @@
+#ifndef _NET_TCP_ECN_H_
+#define _NET_TCP_ECN_H_ 1
+
+#include <net/inet_ecn.h>
+
+#define TCP_HP_BITS (~(TCP_RESERVED_BITS|TCP_FLAG_PSH))
+
+#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_sock *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_sock *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 sock *sk, struct tcp_sock *tp,
+				    struct sk_buff *skb)
+{
+	tp->ecn_flags = 0;
+	if (sysctl_tcp_ecn && !(sk->sk_route_caps & NETIF_F_TSO)) {
+		TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ECE|TCPCB_FLAG_CWR;
+		tp->ecn_flags = TCP_ECN_OK;
+		sock_set_flag(sk, SOCK_NO_LARGESEND);
+	}
+}
+
+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_sock *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_sock *tp, struct sk_buff *skb)
+{
+	if (skb->h.th->cwr)
+		tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR;
+}
+
+static inline void TCP_ECN_withdraw_cwr(struct tcp_sock *tp)
+{
+	tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR;
+}
+
+static inline void TCP_ECN_check_ce(struct tcp_sock *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_not_ect((TCP_SKB_CB(skb)->flags)))
+			tcp_enter_quickack_mode(tp);
+	}
+}
+
+static inline void TCP_ECN_rcv_synack(struct tcp_sock *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_sock *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_sock *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_sock *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;
+}
+
+#endif