1#ifndef _NET_TCP_ECN_H_ 2#define _NET_TCP_ECN_H_ 1 3 4#include <net/inet_ecn.h> 5 6#define TCP_HP_BITS (~(TCP_RESERVED_BITS|TCP_FLAG_PSH)) 7 8#define TCP_ECN_OK 1 9#define TCP_ECN_QUEUE_CWR 2 10#define TCP_ECN_DEMAND_CWR 4 11 12static __inline__ void 13TCP_ECN_queue_cwr(struct tcp_opt *tp) 14{ 15 if (tp->ecn_flags&TCP_ECN_OK) 16 tp->ecn_flags |= TCP_ECN_QUEUE_CWR; 17} 18 19 20/* Output functions */ 21 22static __inline__ void 23TCP_ECN_send_synack(struct tcp_opt *tp, struct sk_buff *skb) 24{ 25 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_CWR; 26 if (!(tp->ecn_flags&TCP_ECN_OK)) 27 TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_ECE; 28} 29 30static __inline__ void 31TCP_ECN_send_syn(struct tcp_opt *tp, struct sk_buff *skb) 32{ 33 tp->ecn_flags = 0; 34 if (sysctl_tcp_ecn) { 35 TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ECE|TCPCB_FLAG_CWR; 36 tp->ecn_flags = TCP_ECN_OK; 37 } 38} 39 40static __inline__ void 41TCP_ECN_make_synack(struct open_request *req, struct tcphdr *th) 42{ 43 if (req->ecn_ok) 44 th->ece = 1; 45} 46 47static __inline__ void 48TCP_ECN_send(struct sock *sk, struct tcp_opt *tp, struct sk_buff *skb, int tcp_header_len) 49{ 50 if (tp->ecn_flags & TCP_ECN_OK) { 51 /* Not-retransmitted data segment: set ECT and inject CWR. */ 52 if (skb->len != tcp_header_len && 53 !before(TCP_SKB_CB(skb)->seq, tp->snd_nxt)) { 54 INET_ECN_xmit(sk); 55 if (tp->ecn_flags&TCP_ECN_QUEUE_CWR) { 56 tp->ecn_flags &= ~TCP_ECN_QUEUE_CWR; 57 skb->h.th->cwr = 1; 58 } 59 } else { 60 /* ACK or retransmitted segment: clear ECT|CE */ 61 INET_ECN_dontxmit(sk); 62 } 63 if (tp->ecn_flags & TCP_ECN_DEMAND_CWR) 64 skb->h.th->ece = 1; 65 } 66} 67 68/* Input functions */ 69 70static __inline__ void 71TCP_ECN_accept_cwr(struct tcp_opt *tp, struct sk_buff *skb) 72{ 73 if (skb->h.th->cwr) 74 tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR; 75} 76 77static __inline__ void 78TCP_ECN_withdraw_cwr(struct tcp_opt *tp) 79{ 80 tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR; 81} 82 83static __inline__ void 84TCP_ECN_check_ce(struct tcp_opt *tp, struct sk_buff *skb) 85{ 86 if (tp->ecn_flags&TCP_ECN_OK) { 87 if (INET_ECN_is_ce(TCP_SKB_CB(skb)->flags)) 88 tp->ecn_flags |= TCP_ECN_DEMAND_CWR; 89 /* Funny extension: if ECT is not set on a segment, 90 * it is surely retransmit. It is not in ECN RFC, 91 * but Linux follows this rule. */ 92 else if (!INET_ECN_is_capable((TCP_SKB_CB(skb)->flags))) 93 tcp_enter_quickack_mode(tp); 94 } 95} 96 97static __inline__ void 98TCP_ECN_rcv_synack(struct tcp_opt *tp, struct tcphdr *th) 99{ 100 if ((tp->ecn_flags&TCP_ECN_OK) && (!th->ece || th->cwr)) 101 tp->ecn_flags &= ~TCP_ECN_OK; 102} 103 104static __inline__ void 105TCP_ECN_rcv_syn(struct tcp_opt *tp, struct tcphdr *th) 106{ 107 if ((tp->ecn_flags&TCP_ECN_OK) && (!th->ece || !th->cwr)) 108 tp->ecn_flags &= ~TCP_ECN_OK; 109} 110 111static __inline__ int 112TCP_ECN_rcv_ecn_echo(struct tcp_opt *tp, struct tcphdr *th) 113{ 114 if (th->ece && !th->syn && (tp->ecn_flags&TCP_ECN_OK)) 115 return 1; 116 return 0; 117} 118 119static __inline__ void 120TCP_ECN_openreq_child(struct tcp_opt *tp, struct open_request *req) 121{ 122 tp->ecn_flags = req->ecn_ok ? TCP_ECN_OK : 0; 123} 124 125static __inline__ void 126TCP_ECN_create_request(struct open_request *req, struct tcphdr *th) 127{ 128 if (sysctl_tcp_ecn && th->ece && th->cwr) 129 req->ecn_ok = 1; 130} 131 132#endif 133