1/*
2 *  net/dccp/ccids/ccid3.h
3 *
4 *  Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand.
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 *  This program is free software; you can redistribute it and/or modify
23 *  it under the terms of the GNU General Public License as published by
24 *  the Free Software Foundation; either version 2 of the License, or
25 *  (at your option) any later version.
26 *
27 *  This program is distributed in the hope that it will be useful,
28 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
29 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
30 *  GNU General Public License for more details.
31 *
32 *  You should have received a copy of the GNU General Public License
33 *  along with this program; if not, write to the Free Software
34 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
35 */
36#ifndef _DCCP_CCID3_H_
37#define _DCCP_CCID3_H_
38
39#include <linux/list.h>
40#include <linux/time.h>
41#include <linux/types.h>
42#include <linux/tfrc.h>
43#include "../ccid.h"
44
45/* Two seconds as per RFC 3448 4.2 */
46#define TFRC_INITIAL_TIMEOUT	   (2 * USEC_PER_SEC)
47
48/* In usecs - half the scheduling granularity as per RFC3448 4.6 */
49#define TFRC_OPSYS_HALF_TIME_GRAN  (USEC_PER_SEC / (2 * HZ))
50
51/* Parameter t_mbi from [RFC 3448, 4.3]: backoff interval in seconds */
52#define TFRC_T_MBI		   64
53
54enum ccid3_options {
55	TFRC_OPT_LOSS_EVENT_RATE = 192,
56	TFRC_OPT_LOSS_INTERVALS	 = 193,
57	TFRC_OPT_RECEIVE_RATE	 = 194,
58};
59
60struct ccid3_options_received {
61	u64 ccid3or_seqno:48,
62	    ccid3or_loss_intervals_idx:16;
63	u16 ccid3or_loss_intervals_len;
64	u32 ccid3or_loss_event_rate;
65	u32 ccid3or_receive_rate;
66};
67
68/* TFRC sender states */
69enum ccid3_hc_tx_states {
70	TFRC_SSTATE_NO_SENT = 1,
71	TFRC_SSTATE_NO_FBACK,
72	TFRC_SSTATE_FBACK,
73	TFRC_SSTATE_TERM,
74};
75
76/** struct ccid3_hc_tx_sock - CCID3 sender half-connection socket
77 *
78 * @ccid3hctx_x - Current sending rate in 64 * bytes per second
79 * @ccid3hctx_x_recv - Receive rate    in 64 * bytes per second
80 * @ccid3hctx_x_calc - Calculated rate in bytes per second
81 * @ccid3hctx_rtt - Estimate of current round trip time in usecs
82 * @ccid3hctx_p - Current loss event rate (0-1) scaled by 1000000
83 * @ccid3hctx_s - Packet size in bytes
84 * @ccid3hctx_t_rto - Nofeedback Timer setting in usecs
85 * @ccid3hctx_t_ipi - Interpacket (send) interval (RFC 3448, 4.6) in usecs
86 * @ccid3hctx_state - Sender state, one of %ccid3_hc_tx_states
87 * @ccid3hctx_last_win_count - Last window counter sent
88 * @ccid3hctx_t_last_win_count - Timestamp of earliest packet
89 *				 with last_win_count value sent
90 * @ccid3hctx_no_feedback_timer - Handle to no feedback timer
91 * @ccid3hctx_idle - Flag indicating that sender is idling
92 * @ccid3hctx_t_ld - Time last doubled during slow start
93 * @ccid3hctx_t_nom - Nominal send time of next packet
94 * @ccid3hctx_delta - Send timer delta (RFC 3448, 4.6) in usecs
95 * @ccid3hctx_hist - Packet history
96 * @ccid3hctx_options_received - Parsed set of retrieved options
97 */
98struct ccid3_hc_tx_sock {
99	struct tfrc_tx_info		ccid3hctx_tfrc;
100#define ccid3hctx_x			ccid3hctx_tfrc.tfrctx_x
101#define ccid3hctx_x_recv		ccid3hctx_tfrc.tfrctx_x_recv
102#define ccid3hctx_x_calc		ccid3hctx_tfrc.tfrctx_x_calc
103#define ccid3hctx_rtt			ccid3hctx_tfrc.tfrctx_rtt
104#define ccid3hctx_p			ccid3hctx_tfrc.tfrctx_p
105#define ccid3hctx_t_rto			ccid3hctx_tfrc.tfrctx_rto
106#define ccid3hctx_t_ipi			ccid3hctx_tfrc.tfrctx_ipi
107	u16				ccid3hctx_s;
108	enum ccid3_hc_tx_states		ccid3hctx_state:8;
109	u8				ccid3hctx_last_win_count;
110	u8				ccid3hctx_idle;
111	struct timeval			ccid3hctx_t_last_win_count;
112	struct timer_list		ccid3hctx_no_feedback_timer;
113	struct timeval			ccid3hctx_t_ld;
114	struct timeval			ccid3hctx_t_nom;
115	u32				ccid3hctx_delta;
116	struct list_head		ccid3hctx_hist;
117	struct ccid3_options_received	ccid3hctx_options_received;
118};
119
120/* TFRC receiver states */
121enum ccid3_hc_rx_states {
122	TFRC_RSTATE_NO_DATA = 1,
123	TFRC_RSTATE_DATA,
124	TFRC_RSTATE_TERM    = 127,
125};
126
127/** struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket
128 *
129 *  @ccid3hcrx_x_recv  -  Receiver estimate of send rate (RFC 3448 4.3)
130 *  @ccid3hcrx_rtt  -  Receiver estimate of rtt (non-standard)
131 *  @ccid3hcrx_p  -  current loss event rate (RFC 3448 5.4)
132 *  @ccid3hcrx_seqno_nonloss  -  Last received non-loss sequence number
133 *  @ccid3hcrx_ccval_nonloss  -  Last received non-loss Window CCVal
134 *  @ccid3hcrx_ccval_last_counter  -  Tracks window counter (RFC 4342, 8.1)
135 *  @ccid3hcrx_state  -  receiver state, one of %ccid3_hc_rx_states
136 *  @ccid3hcrx_bytes_recv  -  Total sum of DCCP payload bytes
137 *  @ccid3hcrx_tstamp_last_feedback  -  Time at which last feedback was sent
138 *  @ccid3hcrx_tstamp_last_ack  -  Time at which last feedback was sent
139 *  @ccid3hcrx_hist  -  Packet history
140 *  @ccid3hcrx_li_hist  -  Loss Interval History
141 *  @ccid3hcrx_s  -  Received packet size in bytes
142 *  @ccid3hcrx_pinv  -  Inverse of Loss Event Rate (RFC 4342, sec. 8.5)
143 *  @ccid3hcrx_elapsed_time  -  Time since packet reception
144 */
145struct ccid3_hc_rx_sock {
146	struct tfrc_rx_info		ccid3hcrx_tfrc;
147#define ccid3hcrx_x_recv		ccid3hcrx_tfrc.tfrcrx_x_recv
148#define ccid3hcrx_rtt			ccid3hcrx_tfrc.tfrcrx_rtt
149#define ccid3hcrx_p			ccid3hcrx_tfrc.tfrcrx_p
150	u64				ccid3hcrx_seqno_nonloss:48,
151					ccid3hcrx_ccval_nonloss:4,
152					ccid3hcrx_ccval_last_counter:4;
153	enum ccid3_hc_rx_states		ccid3hcrx_state:8;
154	u32				ccid3hcrx_bytes_recv;
155	struct timeval			ccid3hcrx_tstamp_last_feedback;
156	struct timeval			ccid3hcrx_tstamp_last_ack;
157	struct list_head		ccid3hcrx_hist;
158	struct list_head		ccid3hcrx_li_hist;
159	u16				ccid3hcrx_s;
160	u32				ccid3hcrx_pinv;
161	u32				ccid3hcrx_elapsed_time;
162};
163
164static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
165{
166    return ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
167}
168
169static inline struct ccid3_hc_rx_sock *ccid3_hc_rx_sk(const struct sock *sk)
170{
171    return ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
172}
173
174#endif /* _DCCP_CCID3_H_ */
175