1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0-or-later */
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand.
4*4882a593Smuzhiyun * Copyright (c) 2007 The University of Aberdeen, Scotland, UK
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * An implementation of the DCCP protocol
7*4882a593Smuzhiyun *
8*4882a593Smuzhiyun * This code has been developed by the University of Waikato WAND
9*4882a593Smuzhiyun * research group. For further information please see https://www.wand.net.nz/
10*4882a593Smuzhiyun * or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz
11*4882a593Smuzhiyun *
12*4882a593Smuzhiyun * This code also uses code from Lulea University, rereleased as GPL by its
13*4882a593Smuzhiyun * authors:
14*4882a593Smuzhiyun * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
15*4882a593Smuzhiyun *
16*4882a593Smuzhiyun * Changes to meet Linux coding standards, to make it meet latest ccid3 draft
17*4882a593Smuzhiyun * and to make it work as a loadable module in the DCCP stack written by
18*4882a593Smuzhiyun * Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
19*4882a593Smuzhiyun *
20*4882a593Smuzhiyun * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
21*4882a593Smuzhiyun */
22*4882a593Smuzhiyun #ifndef _DCCP_CCID3_H_
23*4882a593Smuzhiyun #define _DCCP_CCID3_H_
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun #include <linux/ktime.h>
26*4882a593Smuzhiyun #include <linux/list.h>
27*4882a593Smuzhiyun #include <linux/types.h>
28*4882a593Smuzhiyun #include <linux/tfrc.h>
29*4882a593Smuzhiyun #include "lib/tfrc.h"
30*4882a593Smuzhiyun #include "../ccid.h"
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun /* Two seconds as per RFC 5348, 4.2 */
33*4882a593Smuzhiyun #define TFRC_INITIAL_TIMEOUT (2 * USEC_PER_SEC)
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun /* Parameter t_mbi from [RFC 3448, 4.3]: backoff interval in seconds */
36*4882a593Smuzhiyun #define TFRC_T_MBI 64
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun /*
39*4882a593Smuzhiyun * The t_delta parameter (RFC 5348, 8.3): delays of less than %USEC_PER_MSEC are
40*4882a593Smuzhiyun * rounded down to 0, since sk_reset_timer() here uses millisecond granularity.
41*4882a593Smuzhiyun * Hence we can use a constant t_delta = %USEC_PER_MSEC when HZ >= 500. A coarse
42*4882a593Smuzhiyun * resolution of HZ < 500 means that the error is below one timer tick (t_gran)
43*4882a593Smuzhiyun * when using the constant t_delta = t_gran / 2 = %USEC_PER_SEC / (2 * HZ).
44*4882a593Smuzhiyun */
45*4882a593Smuzhiyun #if (HZ >= 500)
46*4882a593Smuzhiyun # define TFRC_T_DELTA USEC_PER_MSEC
47*4882a593Smuzhiyun #else
48*4882a593Smuzhiyun # define TFRC_T_DELTA (USEC_PER_SEC / (2 * HZ))
49*4882a593Smuzhiyun #endif
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun enum ccid3_options {
52*4882a593Smuzhiyun TFRC_OPT_LOSS_EVENT_RATE = 192,
53*4882a593Smuzhiyun TFRC_OPT_LOSS_INTERVALS = 193,
54*4882a593Smuzhiyun TFRC_OPT_RECEIVE_RATE = 194,
55*4882a593Smuzhiyun };
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun /* TFRC sender states */
58*4882a593Smuzhiyun enum ccid3_hc_tx_states {
59*4882a593Smuzhiyun TFRC_SSTATE_NO_SENT = 1,
60*4882a593Smuzhiyun TFRC_SSTATE_NO_FBACK,
61*4882a593Smuzhiyun TFRC_SSTATE_FBACK,
62*4882a593Smuzhiyun };
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun /**
65*4882a593Smuzhiyun * struct ccid3_hc_tx_sock - CCID3 sender half-connection socket
66*4882a593Smuzhiyun * @tx_x: Current sending rate in 64 * bytes per second
67*4882a593Smuzhiyun * @tx_x_recv: Receive rate in 64 * bytes per second
68*4882a593Smuzhiyun * @tx_x_calc: Calculated rate in bytes per second
69*4882a593Smuzhiyun * @tx_rtt: Estimate of current round trip time in usecs
70*4882a593Smuzhiyun * @tx_p: Current loss event rate (0-1) scaled by 1000000
71*4882a593Smuzhiyun * @tx_s: Packet size in bytes
72*4882a593Smuzhiyun * @tx_t_rto: Nofeedback Timer setting in usecs
73*4882a593Smuzhiyun * @tx_t_ipi: Interpacket (send) interval (RFC 3448, 4.6) in usecs
74*4882a593Smuzhiyun * @tx_state: Sender state, one of %ccid3_hc_tx_states
75*4882a593Smuzhiyun * @tx_last_win_count: Last window counter sent
76*4882a593Smuzhiyun * @tx_t_last_win_count: Timestamp of earliest packet
77*4882a593Smuzhiyun * with last_win_count value sent
78*4882a593Smuzhiyun * @tx_no_feedback_timer: Handle to no feedback timer
79*4882a593Smuzhiyun * @tx_t_ld: Time last doubled during slow start
80*4882a593Smuzhiyun * @tx_t_nom: Nominal send time of next packet
81*4882a593Smuzhiyun * @tx_hist: Packet history
82*4882a593Smuzhiyun */
83*4882a593Smuzhiyun struct ccid3_hc_tx_sock {
84*4882a593Smuzhiyun u64 tx_x;
85*4882a593Smuzhiyun u64 tx_x_recv;
86*4882a593Smuzhiyun u32 tx_x_calc;
87*4882a593Smuzhiyun u32 tx_rtt;
88*4882a593Smuzhiyun u32 tx_p;
89*4882a593Smuzhiyun u32 tx_t_rto;
90*4882a593Smuzhiyun u32 tx_t_ipi;
91*4882a593Smuzhiyun u16 tx_s;
92*4882a593Smuzhiyun enum ccid3_hc_tx_states tx_state:8;
93*4882a593Smuzhiyun u8 tx_last_win_count;
94*4882a593Smuzhiyun ktime_t tx_t_last_win_count;
95*4882a593Smuzhiyun struct timer_list tx_no_feedback_timer;
96*4882a593Smuzhiyun struct sock *sk;
97*4882a593Smuzhiyun ktime_t tx_t_ld;
98*4882a593Smuzhiyun ktime_t tx_t_nom;
99*4882a593Smuzhiyun struct tfrc_tx_hist_entry *tx_hist;
100*4882a593Smuzhiyun };
101*4882a593Smuzhiyun
ccid3_hc_tx_sk(const struct sock * sk)102*4882a593Smuzhiyun static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
103*4882a593Smuzhiyun {
104*4882a593Smuzhiyun struct ccid3_hc_tx_sock *hctx = ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
105*4882a593Smuzhiyun BUG_ON(hctx == NULL);
106*4882a593Smuzhiyun return hctx;
107*4882a593Smuzhiyun }
108*4882a593Smuzhiyun
109*4882a593Smuzhiyun /* TFRC receiver states */
110*4882a593Smuzhiyun enum ccid3_hc_rx_states {
111*4882a593Smuzhiyun TFRC_RSTATE_NO_DATA = 1,
112*4882a593Smuzhiyun TFRC_RSTATE_DATA,
113*4882a593Smuzhiyun };
114*4882a593Smuzhiyun
115*4882a593Smuzhiyun /**
116*4882a593Smuzhiyun * struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket
117*4882a593Smuzhiyun * @rx_last_counter: Tracks window counter (RFC 4342, 8.1)
118*4882a593Smuzhiyun * @rx_state: Receiver state, one of %ccid3_hc_rx_states
119*4882a593Smuzhiyun * @rx_bytes_recv: Total sum of DCCP payload bytes
120*4882a593Smuzhiyun * @rx_x_recv: Receiver estimate of send rate (RFC 3448, sec. 4.3)
121*4882a593Smuzhiyun * @rx_rtt: Receiver estimate of RTT
122*4882a593Smuzhiyun * @rx_tstamp_last_feedback: Time at which last feedback was sent
123*4882a593Smuzhiyun * @rx_hist: Packet history (loss detection + RTT sampling)
124*4882a593Smuzhiyun * @rx_li_hist: Loss Interval database
125*4882a593Smuzhiyun * @rx_s: Received packet size in bytes
126*4882a593Smuzhiyun * @rx_pinv: Inverse of Loss Event Rate (RFC 4342, sec. 8.5)
127*4882a593Smuzhiyun */
128*4882a593Smuzhiyun struct ccid3_hc_rx_sock {
129*4882a593Smuzhiyun u8 rx_last_counter:4;
130*4882a593Smuzhiyun enum ccid3_hc_rx_states rx_state:8;
131*4882a593Smuzhiyun u32 rx_bytes_recv;
132*4882a593Smuzhiyun u32 rx_x_recv;
133*4882a593Smuzhiyun u32 rx_rtt;
134*4882a593Smuzhiyun ktime_t rx_tstamp_last_feedback;
135*4882a593Smuzhiyun struct tfrc_rx_hist rx_hist;
136*4882a593Smuzhiyun struct tfrc_loss_hist rx_li_hist;
137*4882a593Smuzhiyun u16 rx_s;
138*4882a593Smuzhiyun #define rx_pinv rx_li_hist.i_mean
139*4882a593Smuzhiyun };
140*4882a593Smuzhiyun
ccid3_hc_rx_sk(const struct sock * sk)141*4882a593Smuzhiyun static inline struct ccid3_hc_rx_sock *ccid3_hc_rx_sk(const struct sock *sk)
142*4882a593Smuzhiyun {
143*4882a593Smuzhiyun struct ccid3_hc_rx_sock *hcrx = ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
144*4882a593Smuzhiyun BUG_ON(hcrx == NULL);
145*4882a593Smuzhiyun return hcrx;
146*4882a593Smuzhiyun }
147*4882a593Smuzhiyun
148*4882a593Smuzhiyun #endif /* _DCCP_CCID3_H_ */
149