1 /* 2 * Copyright (c) 2005 Andrea Bittau <a.bittau@cs.ucl.ac.uk> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 17 */ 18 #ifndef _DCCP_CCID2_H_ 19 #define _DCCP_CCID2_H_ 20 21 #include <linux/timer.h> 22 #include <linux/types.h> 23 #include "../ccid.h" 24 #include "../dccp.h" 25 26 /* 27 * CCID-2 timestamping faces the same issues as TCP timestamping. 28 * Hence we reuse/share as much of the code as possible. 29 */ 30 #define ccid2_time_stamp tcp_time_stamp 31 32 /* NUMDUPACK parameter from RFC 4341, p. 6 */ 33 #define NUMDUPACK 3 34 35 struct ccid2_seq { 36 u64 ccid2s_seq; 37 u32 ccid2s_sent; 38 int ccid2s_acked; 39 struct ccid2_seq *ccid2s_prev; 40 struct ccid2_seq *ccid2s_next; 41 }; 42 43 #define CCID2_SEQBUF_LEN 1024 44 #define CCID2_SEQBUF_MAX 128 45 46 /* 47 * Multiple of congestion window to keep the sequence window at 48 * (RFC 4340 7.5.2) 49 */ 50 #define CCID2_WIN_CHANGE_FACTOR 5 51 52 /** 53 * struct ccid2_hc_tx_sock - CCID2 TX half connection 54 * @tx_{cwnd,ssthresh,pipe}: as per RFC 4341, section 5 55 * @tx_packets_acked: Ack counter for deriving cwnd growth (RFC 3465) 56 * @tx_srtt: smoothed RTT estimate, scaled by 2^3 57 * @tx_mdev: smoothed RTT variation, scaled by 2^2 58 * @tx_mdev_max: maximum of @mdev during one flight 59 * @tx_rttvar: moving average/maximum of @mdev_max 60 * @tx_rto: RTO value deriving from SRTT and RTTVAR (RFC 2988) 61 * @tx_rtt_seq: to decay RTTVAR at most once per flight 62 * @tx_cwnd_used: actually used cwnd, W_used of RFC 2861 63 * @tx_expected_wnd: moving average of @tx_cwnd_used 64 * @tx_cwnd_stamp: to track idle periods in CWV 65 * @tx_lsndtime: last time (in jiffies) a data packet was sent 66 * @tx_rpseq: last consecutive seqno 67 * @tx_rpdupack: dupacks since rpseq 68 * @tx_av_chunks: list of Ack Vectors received on current skb 69 */ 70 struct ccid2_hc_tx_sock { 71 u32 tx_cwnd; 72 u32 tx_ssthresh; 73 u32 tx_pipe; 74 u32 tx_packets_acked; 75 struct ccid2_seq *tx_seqbuf[CCID2_SEQBUF_MAX]; 76 int tx_seqbufc; 77 struct ccid2_seq *tx_seqh; 78 struct ccid2_seq *tx_seqt; 79 80 /* RTT measurement: variables/principles are the same as in TCP */ 81 u32 tx_srtt, 82 tx_mdev, 83 tx_mdev_max, 84 tx_rttvar, 85 tx_rto; 86 u64 tx_rtt_seq:48; 87 struct timer_list tx_rtotimer; 88 89 /* Congestion Window validation (optional, RFC 2861) */ 90 u32 tx_cwnd_used, 91 tx_expected_wnd, 92 tx_cwnd_stamp, 93 tx_lsndtime; 94 95 u64 tx_rpseq; 96 int tx_rpdupack; 97 u32 tx_last_cong; 98 u64 tx_high_ack; 99 struct list_head tx_av_chunks; 100 }; 101 102 static inline bool ccid2_cwnd_network_limited(struct ccid2_hc_tx_sock *hc) 103 { 104 return hc->tx_pipe >= hc->tx_cwnd; 105 } 106 107 /* 108 * Convert RFC 3390 larger initial window into an equivalent number of packets. 109 * This is based on the numbers specified in RFC 5681, 3.1. 110 */ 111 static inline u32 rfc3390_bytes_to_packets(const u32 smss) 112 { 113 return smss <= 1095 ? 4 : (smss > 2190 ? 2 : 3); 114 } 115 116 /** 117 * struct ccid2_hc_rx_sock - Receiving end of CCID-2 half-connection 118 * @rx_num_data_pkts: number of data packets received since last feedback 119 */ 120 struct ccid2_hc_rx_sock { 121 u32 rx_num_data_pkts; 122 }; 123 124 static inline struct ccid2_hc_tx_sock *ccid2_hc_tx_sk(const struct sock *sk) 125 { 126 return ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid); 127 } 128 129 static inline struct ccid2_hc_rx_sock *ccid2_hc_rx_sk(const struct sock *sk) 130 { 131 return ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid); 132 } 133 #endif /* _DCCP_CCID2_H_ */ 134