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) { 35 TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_ECE|TCPCB_FLAG_CWR; 36 tp->ecn_flags = TCP_ECN_OK; 37 } 38 } 39 40 static __inline__ void 41 TCP_ECN_make_synack(struct request_sock *req, struct tcphdr *th) 42 { 43 if (inet_rsk(req)->ecn_ok) 44 th->ece = 1; 45 } 46 47 static inline void TCP_ECN_send(struct sock *sk, struct tcp_sock *tp, 48 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 if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) 59 skb_shinfo(skb)->gso_type |= 60 SKB_GSO_TCPV4_ECN; 61 } 62 } else { 63 /* ACK or retransmitted segment: clear ECT|CE */ 64 INET_ECN_dontxmit(sk); 65 } 66 if (tp->ecn_flags & TCP_ECN_DEMAND_CWR) 67 skb->h.th->ece = 1; 68 } 69 } 70 71 /* Input functions */ 72 73 static inline void TCP_ECN_accept_cwr(struct tcp_sock *tp, struct sk_buff *skb) 74 { 75 if (skb->h.th->cwr) 76 tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR; 77 } 78 79 static inline void TCP_ECN_withdraw_cwr(struct tcp_sock *tp) 80 { 81 tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR; 82 } 83 84 static inline void TCP_ECN_check_ce(struct tcp_sock *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_not_ect((TCP_SKB_CB(skb)->flags))) 93 tcp_enter_quickack_mode((struct sock *)tp); 94 } 95 } 96 97 static inline void TCP_ECN_rcv_synack(struct tcp_sock *tp, struct tcphdr *th) 98 { 99 if ((tp->ecn_flags&TCP_ECN_OK) && (!th->ece || th->cwr)) 100 tp->ecn_flags &= ~TCP_ECN_OK; 101 } 102 103 static inline void TCP_ECN_rcv_syn(struct tcp_sock *tp, struct tcphdr *th) 104 { 105 if ((tp->ecn_flags&TCP_ECN_OK) && (!th->ece || !th->cwr)) 106 tp->ecn_flags &= ~TCP_ECN_OK; 107 } 108 109 static inline int TCP_ECN_rcv_ecn_echo(struct tcp_sock *tp, struct tcphdr *th) 110 { 111 if (th->ece && !th->syn && (tp->ecn_flags&TCP_ECN_OK)) 112 return 1; 113 return 0; 114 } 115 116 static inline void TCP_ECN_openreq_child(struct tcp_sock *tp, 117 struct request_sock *req) 118 { 119 tp->ecn_flags = inet_rsk(req)->ecn_ok ? TCP_ECN_OK : 0; 120 } 121 122 static __inline__ void 123 TCP_ECN_create_request(struct request_sock *req, struct tcphdr *th) 124 { 125 if (sysctl_tcp_ecn && th->ece && th->cwr) 126 inet_rsk(req)->ecn_ok = 1; 127 } 128 129 #endif 130