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