1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
2 | /* |
3 | * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand. |
4 | * Copyright (c) 2007 The University of Aberdeen, Scotland, UK |
5 | * |
6 | * An implementation of the DCCP protocol |
7 | * |
8 | * This code has been developed by the University of Waikato WAND |
9 | * research group. For further information please see https://www.wand.net.nz/ |
10 | * or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz |
11 | * |
12 | * This code also uses code from Lulea University, rereleased as GPL by its |
13 | * authors: |
14 | * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon |
15 | * |
16 | * Changes to meet Linux coding standards, to make it meet latest ccid3 draft |
17 | * and to make it work as a loadable module in the DCCP stack written by |
18 | * Arnaldo Carvalho de Melo <acme@conectiva.com.br>. |
19 | * |
20 | * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br> |
21 | */ |
22 | #ifndef _DCCP_CCID3_H_ |
23 | #define _DCCP_CCID3_H_ |
24 | |
25 | #include <linux/ktime.h> |
26 | #include <linux/list.h> |
27 | #include <linux/types.h> |
28 | #include <linux/tfrc.h> |
29 | #include "lib/tfrc.h" |
30 | #include "../ccid.h" |
31 | |
32 | /* Two seconds as per RFC 5348, 4.2 */ |
33 | #define TFRC_INITIAL_TIMEOUT (2 * USEC_PER_SEC) |
34 | |
35 | /* Parameter t_mbi from [RFC 3448, 4.3]: backoff interval in seconds */ |
36 | #define TFRC_T_MBI 64 |
37 | |
38 | /* |
39 | * The t_delta parameter (RFC 5348, 8.3): delays of less than %USEC_PER_MSEC are |
40 | * rounded down to 0, since sk_reset_timer() here uses millisecond granularity. |
41 | * Hence we can use a constant t_delta = %USEC_PER_MSEC when HZ >= 500. A coarse |
42 | * resolution of HZ < 500 means that the error is below one timer tick (t_gran) |
43 | * when using the constant t_delta = t_gran / 2 = %USEC_PER_SEC / (2 * HZ). |
44 | */ |
45 | #if (HZ >= 500) |
46 | # define TFRC_T_DELTA USEC_PER_MSEC |
47 | #else |
48 | # define TFRC_T_DELTA (USEC_PER_SEC / (2 * HZ)) |
49 | #endif |
50 | |
51 | enum ccid3_options { |
52 | TFRC_OPT_LOSS_EVENT_RATE = 192, |
53 | TFRC_OPT_LOSS_INTERVALS = 193, |
54 | TFRC_OPT_RECEIVE_RATE = 194, |
55 | }; |
56 | |
57 | /* TFRC sender states */ |
58 | enum ccid3_hc_tx_states { |
59 | TFRC_SSTATE_NO_SENT = 1, |
60 | TFRC_SSTATE_NO_FBACK, |
61 | TFRC_SSTATE_FBACK, |
62 | }; |
63 | |
64 | /** |
65 | * struct ccid3_hc_tx_sock - CCID3 sender half-connection socket |
66 | * @tx_x: Current sending rate in 64 * bytes per second |
67 | * @tx_x_recv: Receive rate in 64 * bytes per second |
68 | * @tx_x_calc: Calculated rate in bytes per second |
69 | * @tx_rtt: Estimate of current round trip time in usecs |
70 | * @tx_p: Current loss event rate (0-1) scaled by 1000000 |
71 | * @tx_s: Packet size in bytes |
72 | * @tx_t_rto: Nofeedback Timer setting in usecs |
73 | * @tx_t_ipi: Interpacket (send) interval (RFC 3448, 4.6) in usecs |
74 | * @tx_state: Sender state, one of %ccid3_hc_tx_states |
75 | * @tx_last_win_count: Last window counter sent |
76 | * @tx_t_last_win_count: Timestamp of earliest packet |
77 | * with last_win_count value sent |
78 | * @tx_no_feedback_timer: Handle to no feedback timer |
79 | * @tx_t_ld: Time last doubled during slow start |
80 | * @tx_t_nom: Nominal send time of next packet |
81 | * @tx_hist: Packet history |
82 | */ |
83 | struct ccid3_hc_tx_sock { |
84 | u64 tx_x; |
85 | u64 tx_x_recv; |
86 | u32 tx_x_calc; |
87 | u32 tx_rtt; |
88 | u32 tx_p; |
89 | u32 tx_t_rto; |
90 | u32 tx_t_ipi; |
91 | u16 tx_s; |
92 | enum ccid3_hc_tx_states tx_state:8; |
93 | u8 tx_last_win_count; |
94 | ktime_t tx_t_last_win_count; |
95 | struct timer_list tx_no_feedback_timer; |
96 | struct sock *sk; |
97 | ktime_t tx_t_ld; |
98 | ktime_t tx_t_nom; |
99 | struct tfrc_tx_hist_entry *tx_hist; |
100 | }; |
101 | |
102 | static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk) |
103 | { |
104 | struct ccid3_hc_tx_sock *hctx = ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid); |
105 | BUG_ON(hctx == NULL); |
106 | return hctx; |
107 | } |
108 | |
109 | /* TFRC receiver states */ |
110 | enum ccid3_hc_rx_states { |
111 | TFRC_RSTATE_NO_DATA = 1, |
112 | TFRC_RSTATE_DATA, |
113 | }; |
114 | |
115 | /** |
116 | * struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket |
117 | * @rx_last_counter: Tracks window counter (RFC 4342, 8.1) |
118 | * @rx_state: Receiver state, one of %ccid3_hc_rx_states |
119 | * @rx_bytes_recv: Total sum of DCCP payload bytes |
120 | * @rx_x_recv: Receiver estimate of send rate (RFC 3448, sec. 4.3) |
121 | * @rx_rtt: Receiver estimate of RTT |
122 | * @rx_tstamp_last_feedback: Time at which last feedback was sent |
123 | * @rx_hist: Packet history (loss detection + RTT sampling) |
124 | * @rx_li_hist: Loss Interval database |
125 | * @rx_s: Received packet size in bytes |
126 | * @rx_pinv: Inverse of Loss Event Rate (RFC 4342, sec. 8.5) |
127 | */ |
128 | struct ccid3_hc_rx_sock { |
129 | u8 rx_last_counter:4; |
130 | enum ccid3_hc_rx_states rx_state:8; |
131 | u32 rx_bytes_recv; |
132 | u32 rx_x_recv; |
133 | u32 rx_rtt; |
134 | ktime_t rx_tstamp_last_feedback; |
135 | struct tfrc_rx_hist rx_hist; |
136 | struct tfrc_loss_hist rx_li_hist; |
137 | u16 rx_s; |
138 | #define rx_pinv rx_li_hist.i_mean |
139 | }; |
140 | |
141 | static inline struct ccid3_hc_rx_sock *ccid3_hc_rx_sk(const struct sock *sk) |
142 | { |
143 | struct ccid3_hc_rx_sock *hcrx = ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid); |
144 | BUG_ON(hcrx == NULL); |
145 | return hcrx; |
146 | } |
147 | |
148 | #endif /* _DCCP_CCID3_H_ */ |
149 | |