1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
2 | /* |
3 | * Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk> |
4 | */ |
5 | #ifndef _DCCP_CCID2_H_ |
6 | #define _DCCP_CCID2_H_ |
7 | |
8 | #include <linux/timer.h> |
9 | #include <linux/types.h> |
10 | #include "../ccid.h" |
11 | #include "../dccp.h" |
12 | |
13 | /* |
14 | * CCID-2 timestamping faces the same issues as TCP timestamping. |
15 | * Hence we reuse/share as much of the code as possible. |
16 | */ |
17 | #define ccid2_jiffies32 ((u32)jiffies) |
18 | |
19 | /* NUMDUPACK parameter from RFC 4341, p. 6 */ |
20 | #define NUMDUPACK 3 |
21 | |
22 | struct ccid2_seq { |
23 | u64 ccid2s_seq; |
24 | u32 ccid2s_sent; |
25 | int ccid2s_acked; |
26 | struct ccid2_seq *ccid2s_prev; |
27 | struct ccid2_seq *ccid2s_next; |
28 | }; |
29 | |
30 | #define CCID2_SEQBUF_LEN 1024 |
31 | #define CCID2_SEQBUF_MAX 128 |
32 | |
33 | /* |
34 | * Multiple of congestion window to keep the sequence window at |
35 | * (RFC 4340 7.5.2) |
36 | */ |
37 | #define CCID2_WIN_CHANGE_FACTOR 5 |
38 | |
39 | /** |
40 | * struct ccid2_hc_tx_sock - CCID2 TX half connection |
41 | * @tx_{cwnd,ssthresh,pipe}: as per RFC 4341, section 5 |
42 | * @tx_packets_acked: Ack counter for deriving cwnd growth (RFC 3465) |
43 | * @tx_srtt: smoothed RTT estimate, scaled by 2^3 |
44 | * @tx_mdev: smoothed RTT variation, scaled by 2^2 |
45 | * @tx_mdev_max: maximum of @mdev during one flight |
46 | * @tx_rttvar: moving average/maximum of @mdev_max |
47 | * @tx_rto: RTO value deriving from SRTT and RTTVAR (RFC 2988) |
48 | * @tx_rtt_seq: to decay RTTVAR at most once per flight |
49 | * @tx_cwnd_used: actually used cwnd, W_used of RFC 2861 |
50 | * @tx_expected_wnd: moving average of @tx_cwnd_used |
51 | * @tx_cwnd_stamp: to track idle periods in CWV |
52 | * @tx_lsndtime: last time (in jiffies) a data packet was sent |
53 | * @tx_rpseq: last consecutive seqno |
54 | * @tx_rpdupack: dupacks since rpseq |
55 | * @tx_av_chunks: list of Ack Vectors received on current skb |
56 | */ |
57 | struct ccid2_hc_tx_sock { |
58 | u32 tx_cwnd; |
59 | u32 tx_ssthresh; |
60 | u32 tx_pipe; |
61 | u32 tx_packets_acked; |
62 | struct ccid2_seq *tx_seqbuf[CCID2_SEQBUF_MAX]; |
63 | int tx_seqbufc; |
64 | struct ccid2_seq *tx_seqh; |
65 | struct ccid2_seq *tx_seqt; |
66 | |
67 | /* RTT measurement: variables/principles are the same as in TCP */ |
68 | u32 tx_srtt, |
69 | tx_mdev, |
70 | tx_mdev_max, |
71 | tx_rttvar, |
72 | tx_rto; |
73 | u64 tx_rtt_seq:48; |
74 | struct timer_list tx_rtotimer; |
75 | struct sock *sk; |
76 | |
77 | /* Congestion Window validation (optional, RFC 2861) */ |
78 | u32 tx_cwnd_used, |
79 | tx_expected_wnd, |
80 | tx_cwnd_stamp, |
81 | tx_lsndtime; |
82 | |
83 | u64 tx_rpseq; |
84 | int tx_rpdupack; |
85 | u32 tx_last_cong; |
86 | u64 tx_high_ack; |
87 | struct list_head tx_av_chunks; |
88 | }; |
89 | |
90 | static inline bool ccid2_cwnd_network_limited(struct ccid2_hc_tx_sock *hc) |
91 | { |
92 | return hc->tx_pipe >= hc->tx_cwnd; |
93 | } |
94 | |
95 | /* |
96 | * Convert RFC 3390 larger initial window into an equivalent number of packets. |
97 | * This is based on the numbers specified in RFC 5681, 3.1. |
98 | */ |
99 | static inline u32 rfc3390_bytes_to_packets(const u32 smss) |
100 | { |
101 | return smss <= 1095 ? 4 : (smss > 2190 ? 2 : 3); |
102 | } |
103 | |
104 | /** |
105 | * struct ccid2_hc_rx_sock - Receiving end of CCID-2 half-connection |
106 | * @rx_num_data_pkts: number of data packets received since last feedback |
107 | */ |
108 | struct ccid2_hc_rx_sock { |
109 | u32 rx_num_data_pkts; |
110 | }; |
111 | |
112 | static inline struct ccid2_hc_tx_sock *ccid2_hc_tx_sk(const struct sock *sk) |
113 | { |
114 | return ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid); |
115 | } |
116 | |
117 | static inline struct ccid2_hc_rx_sock *ccid2_hc_rx_sk(const struct sock *sk) |
118 | { |
119 | return ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid); |
120 | } |
121 | #endif /* _DCCP_CCID2_H_ */ |
122 | |