2 * net/dccp/ccids/ccid3.h
4 * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand.
5 * Copyright (c) 2007 The University of Aberdeen, Scotland, UK
7 * An implementation of the DCCP protocol
9 * This code has been developed by the University of Waikato WAND
10 * research group. For further information please see http://www.wand.net.nz/
11 * or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz
13 * This code also uses code from Lulea University, rereleased as GPL by its
15 * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
17 * Changes to meet Linux coding standards, to make it meet latest ccid3 draft
18 * and to make it work as a loadable module in the DCCP stack written by
19 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
21 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
23 * This program is free software; you can redistribute it and/or modify
24 * it under the terms of the GNU General Public License as published by
25 * the Free Software Foundation; either version 2 of the License, or
26 * (at your option) any later version.
28 * This program is distributed in the hope that it will be useful,
29 * but WITHOUT ANY WARRANTY; without even the implied warranty of
30 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
31 * GNU General Public License for more details.
33 * You should have received a copy of the GNU General Public License
34 * along with this program; if not, write to the Free Software
35 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
37 #ifndef _DCCP_CCID3_H_
38 #define _DCCP_CCID3_H_
40 #include <linux/ktime.h>
41 #include <linux/list.h>
42 #include <linux/types.h>
43 #include <linux/tfrc.h>
47 /* Two seconds as per RFC 3448 4.2 */
48 #define TFRC_INITIAL_TIMEOUT (2 * USEC_PER_SEC)
50 /* Parameter t_mbi from [RFC 3448, 4.3]: backoff interval in seconds */
54 * The t_delta parameter (RFC 3448, 4.6): delays of less than %USEC_PER_MSEC are
55 * rounded down to 0, since sk_reset_timer() here uses millisecond granularity.
56 * Hence we can use a constant t_delta = %USEC_PER_MSEC when HZ >= 500. A coarse
57 * resolution of HZ < 500 means that the error is below one timer tick (t_gran)
58 * when using the constant t_delta = t_gran / 2 = %USEC_PER_SEC / (2 * HZ).
61 # define TFRC_T_DELTA USEC_PER_MSEC
63 # define TFRC_T_DELTA (USEC_PER_SEC / (2 * HZ))
64 #warning Coarse CONFIG_HZ resolution -- higher value recommended for TFRC.
68 TFRC_OPT_LOSS_EVENT_RATE = 192,
69 TFRC_OPT_LOSS_INTERVALS = 193,
70 TFRC_OPT_RECEIVE_RATE = 194,
73 /* TFRC sender states */
74 enum ccid3_hc_tx_states {
75 TFRC_SSTATE_NO_SENT = 1,
80 /** struct ccid3_hc_tx_sock - CCID3 sender half-connection socket
82 * @x - Current sending rate in 64 * bytes per second
83 * @x_recv - Receive rate in 64 * bytes per second
84 * @x_calc - Calculated rate in bytes per second
85 * @rtt - Estimate of current round trip time in usecs
86 * @p - Current loss event rate (0-1) scaled by 1000000
87 * @s - Packet size in bytes
88 * @t_rto - Nofeedback Timer setting in usecs
89 * @t_ipi - Interpacket (send) interval (RFC 3448, 4.6) in usecs
90 * @state - Sender state, one of %ccid3_hc_tx_states
91 * @last_win_count - Last window counter sent
92 * @t_last_win_count - Timestamp of earliest packet with
93 * last_win_count value sent
94 * @no_feedback_timer - Handle to no feedback timer
95 * @t_ld - Time last doubled during slow start
96 * @t_nom - Nominal send time of next packet
97 * @hist - Packet history
99 struct ccid3_hc_tx_sock {
108 enum ccid3_hc_tx_states state:8;
110 ktime_t t_last_win_count;
111 struct timer_list no_feedback_timer;
114 struct tfrc_tx_hist_entry *hist;
117 static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
119 struct ccid3_hc_tx_sock *hctx = ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
120 BUG_ON(hctx == NULL);
124 /* TFRC receiver states */
125 enum ccid3_hc_rx_states {
126 TFRC_RSTATE_NO_DATA = 1,
130 /** struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket
132 * @last_counter - Tracks window counter (RFC 4342, 8.1)
133 * @state - Receiver state, one of %ccid3_hc_rx_states
134 * @bytes_recv - Total sum of DCCP payload bytes
135 * @x_recv - Receiver estimate of send rate (RFC 3448, sec. 4.3)
136 * @rtt - Receiver estimate of RTT
137 * @tstamp_last_feedback - Time at which last feedback was sent
138 * @hist - Packet history (loss detection + RTT sampling)
139 * @li_hist - Loss Interval database
140 * @s - Received packet size in bytes
141 * @p_inverse - Inverse of Loss Event Rate (RFC 4342, sec. 8.5)
143 struct ccid3_hc_rx_sock {
145 enum ccid3_hc_rx_states state:8;
149 ktime_t tstamp_last_feedback;
150 struct tfrc_rx_hist hist;
151 struct tfrc_loss_hist li_hist;
153 #define p_inverse li_hist.i_mean
156 static inline struct ccid3_hc_rx_sock *ccid3_hc_rx_sk(const struct sock *sk)
158 struct ccid3_hc_rx_sock *hcrx = ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
159 BUG_ON(hcrx == NULL);
163 #endif /* _DCCP_CCID3_H_ */