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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
13static 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
22static 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
30static 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
40static __inline__ void
41TCP_ECN_make_synack(struct request_sock *req, struct tcphdr *th)
42{
43 if (inet_rsk(req)->ecn_ok)
44 th->ece = 1;
45}
46
47static 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 skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;
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
71static 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
77static inline void TCP_ECN_withdraw_cwr(struct tcp_sock *tp)
78{
79 tp->ecn_flags &= ~TCP_ECN_DEMAND_CWR;
80}
81
82static 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((struct sock *)tp);
92 }
93}
94
95static 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
101static 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
107static 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
114static 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
120static __inline__ void
121TCP_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