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 http://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 51enum 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 */ 58enum 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 */ 83struct 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 102static 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 */ 110enum 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 */ 128struct 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 141static 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