xref: /openbmc/linux/net/dccp/ccids/ccid3.h (revision 384740dc)
1 /*
2  *  net/dccp/ccids/ccid3.h
3  *
4  *  Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand.
5  *  Copyright (c) 2007   The University of Aberdeen, Scotland, UK
6  *
7  *  An implementation of the DCCP protocol
8  *
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
12  *
13  *  This code also uses code from Lulea University, rereleased as GPL by its
14  *  authors:
15  *  Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
16  *
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>.
20  *
21  *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
22  *
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.
27  *
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.
32  *
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.
36  */
37 #ifndef _DCCP_CCID3_H_
38 #define _DCCP_CCID3_H_
39 
40 #include <linux/ktime.h>
41 #include <linux/list.h>
42 #include <linux/types.h>
43 #include <linux/tfrc.h>
44 #include "lib/tfrc.h"
45 #include "../ccid.h"
46 
47 /* Two seconds as per RFC 3448 4.2 */
48 #define TFRC_INITIAL_TIMEOUT	   (2 * USEC_PER_SEC)
49 
50 /* In usecs - half the scheduling granularity as per RFC3448 4.6 */
51 #define TFRC_OPSYS_HALF_TIME_GRAN  (USEC_PER_SEC / (2 * HZ))
52 
53 /* Parameter t_mbi from [RFC 3448, 4.3]: backoff interval in seconds */
54 #define TFRC_T_MBI		   64
55 
56 enum ccid3_options {
57 	TFRC_OPT_LOSS_EVENT_RATE = 192,
58 	TFRC_OPT_LOSS_INTERVALS	 = 193,
59 	TFRC_OPT_RECEIVE_RATE	 = 194,
60 };
61 
62 struct ccid3_options_received {
63 	u64 ccid3or_seqno:48,
64 	    ccid3or_loss_intervals_idx:16;
65 	u16 ccid3or_loss_intervals_len;
66 	u32 ccid3or_loss_event_rate;
67 	u32 ccid3or_receive_rate;
68 };
69 
70 /* TFRC sender states */
71 enum ccid3_hc_tx_states {
72 	TFRC_SSTATE_NO_SENT = 1,
73 	TFRC_SSTATE_NO_FBACK,
74 	TFRC_SSTATE_FBACK,
75 	TFRC_SSTATE_TERM,
76 };
77 
78 /** struct ccid3_hc_tx_sock - CCID3 sender half-connection socket
79  *
80  * @ccid3hctx_x - Current sending rate in 64 * bytes per second
81  * @ccid3hctx_x_recv - Receive rate    in 64 * bytes per second
82  * @ccid3hctx_x_calc - Calculated rate in bytes per second
83  * @ccid3hctx_rtt - Estimate of current round trip time in usecs
84  * @ccid3hctx_p - Current loss event rate (0-1) scaled by 1000000
85  * @ccid3hctx_s - Packet size in bytes
86  * @ccid3hctx_t_rto - Nofeedback Timer setting in usecs
87  * @ccid3hctx_t_ipi - Interpacket (send) interval (RFC 3448, 4.6) in usecs
88  * @ccid3hctx_state - Sender state, one of %ccid3_hc_tx_states
89  * @ccid3hctx_last_win_count - Last window counter sent
90  * @ccid3hctx_t_last_win_count - Timestamp of earliest packet
91  *				 with last_win_count value sent
92  * @ccid3hctx_no_feedback_timer - Handle to no feedback timer
93  * @ccid3hctx_t_ld - Time last doubled during slow start
94  * @ccid3hctx_t_nom - Nominal send time of next packet
95  * @ccid3hctx_delta - Send timer delta (RFC 3448, 4.6) in usecs
96  * @ccid3hctx_hist - Packet history
97  * @ccid3hctx_options_received - Parsed set of retrieved options
98  */
99 struct ccid3_hc_tx_sock {
100 	struct tfrc_tx_info		ccid3hctx_tfrc;
101 #define ccid3hctx_x			ccid3hctx_tfrc.tfrctx_x
102 #define ccid3hctx_x_recv		ccid3hctx_tfrc.tfrctx_x_recv
103 #define ccid3hctx_x_calc		ccid3hctx_tfrc.tfrctx_x_calc
104 #define ccid3hctx_rtt			ccid3hctx_tfrc.tfrctx_rtt
105 #define ccid3hctx_p			ccid3hctx_tfrc.tfrctx_p
106 #define ccid3hctx_t_rto			ccid3hctx_tfrc.tfrctx_rto
107 #define ccid3hctx_t_ipi			ccid3hctx_tfrc.tfrctx_ipi
108 	u16				ccid3hctx_s;
109 	enum ccid3_hc_tx_states		ccid3hctx_state:8;
110 	u8				ccid3hctx_last_win_count;
111 	ktime_t				ccid3hctx_t_last_win_count;
112 	struct timer_list		ccid3hctx_no_feedback_timer;
113 	ktime_t				ccid3hctx_t_ld;
114 	ktime_t				ccid3hctx_t_nom;
115 	u32				ccid3hctx_delta;
116 	struct tfrc_tx_hist_entry	*ccid3hctx_hist;
117 	struct ccid3_options_received	ccid3hctx_options_received;
118 };
119 
120 static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
121 {
122     struct ccid3_hc_tx_sock *hctx = ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
123     BUG_ON(hctx == NULL);
124     return hctx;
125 }
126 
127 /* TFRC receiver states */
128 enum ccid3_hc_rx_states {
129 	TFRC_RSTATE_NO_DATA = 1,
130 	TFRC_RSTATE_DATA,
131 	TFRC_RSTATE_TERM    = 127,
132 };
133 
134 /** struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket
135  *
136  *  @ccid3hcrx_x_recv  -  Receiver estimate of send rate (RFC 3448 4.3)
137  *  @ccid3hcrx_rtt  -  Receiver estimate of rtt (non-standard)
138  *  @ccid3hcrx_p  -  Current loss event rate (RFC 3448 5.4)
139  *  @ccid3hcrx_last_counter  -  Tracks window counter (RFC 4342, 8.1)
140  *  @ccid3hcrx_state  -  Receiver state, one of %ccid3_hc_rx_states
141  *  @ccid3hcrx_bytes_recv  -  Total sum of DCCP payload bytes
142  *  @ccid3hcrx_x_recv  -  Receiver estimate of send rate (RFC 3448, sec. 4.3)
143  *  @ccid3hcrx_rtt  -  Receiver estimate of RTT
144  *  @ccid3hcrx_tstamp_last_feedback  -  Time at which last feedback was sent
145  *  @ccid3hcrx_tstamp_last_ack  -  Time at which last feedback was sent
146  *  @ccid3hcrx_hist  -  Packet history (loss detection + RTT sampling)
147  *  @ccid3hcrx_li_hist  -  Loss Interval database
148  *  @ccid3hcrx_s  -  Received packet size in bytes
149  *  @ccid3hcrx_pinv  -  Inverse of Loss Event Rate (RFC 4342, sec. 8.5)
150  */
151 struct ccid3_hc_rx_sock {
152 	u8				ccid3hcrx_last_counter:4;
153 	enum ccid3_hc_rx_states		ccid3hcrx_state:8;
154 	u32				ccid3hcrx_bytes_recv;
155 	u32				ccid3hcrx_x_recv;
156 	u32				ccid3hcrx_rtt;
157 	ktime_t				ccid3hcrx_tstamp_last_feedback;
158 	struct tfrc_rx_hist		ccid3hcrx_hist;
159 	struct tfrc_loss_hist		ccid3hcrx_li_hist;
160 	u16				ccid3hcrx_s;
161 #define ccid3hcrx_pinv			ccid3hcrx_li_hist.i_mean
162 };
163 
164 static inline struct ccid3_hc_rx_sock *ccid3_hc_rx_sk(const struct sock *sk)
165 {
166     struct ccid3_hc_rx_sock *hcrx = ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
167     BUG_ON(hcrx == NULL);
168     return hcrx;
169 }
170 
171 #endif /* _DCCP_CCID3_H_ */
172