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 22struct 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 */ 57struct 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 90static 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 */ 99static 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 */ 108struct ccid2_hc_rx_sock { 109 u32 rx_num_data_pkts; 110}; 111 112static 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 117static 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