1 /*
2 * Copyright (c) 2005-7 The University of Waikato, Hamilton, New Zealand.
3 * Copyright (c) 2007 The University of Aberdeen, Scotland, UK
4 *
5 * An implementation of the DCCP protocol
6 *
7 * This code has been developed by the University of Waikato WAND
8 * research group. For further information please see http://www.wand.net.nz/
9 * or e-mail Ian McDonald - ian.mcdonald@jandi.co.nz
10 *
11 * This code also uses code from Lulea University, rereleased as GPL by its
12 * authors:
13 * Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
14 *
15 * Changes to meet Linux coding standards, to make it meet latest ccid3 draft
16 * and to make it work as a loadable module in the DCCP stack written by
17 * Arnaldo Carvalho de Melo <acme@conectiva.com.br>.
18 *
19 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
20 *
21 * This program is free software; you can redistribute it and/or modify
22 * it under the terms of the GNU General Public License as published by
23 * the Free Software Foundation; either version 2 of the License, or
24 * (at your option) any later version.
25 *
26 * This program is distributed in the hope that it will be useful,
27 * but WITHOUT ANY WARRANTY; without even the implied warranty of
28 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
29 * GNU General Public License for more details.
30 *
31 * You should have received a copy of the GNU General Public License
32 * along with this program; if not, write to the Free Software
33 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
34 */
35 #ifndef _DCCP_CCID3_H_
36 #define _DCCP_CCID3_H_
37
38 #include <linux/ktime.h>
39 #include <linux/list.h>
40 #include <linux/types.h>
41 #include <linux/tfrc.h>
42 #include "lib/tfrc.h"
43 #include "../ccid.h"
44
45 /* Two seconds as per RFC 5348, 4.2 */
46 #define TFRC_INITIAL_TIMEOUT (2 * USEC_PER_SEC)
47
48 /* Parameter t_mbi from [RFC 3448, 4.3]: backoff interval in seconds */
49 #define TFRC_T_MBI 64
50
51 /*
52 * The t_delta parameter (RFC 5348, 8.3): delays of less than %USEC_PER_MSEC are
53 * rounded down to 0, since sk_reset_timer() here uses millisecond granularity.
54 * Hence we can use a constant t_delta = %USEC_PER_MSEC when HZ >= 500. A coarse
55 * resolution of HZ < 500 means that the error is below one timer tick (t_gran)
56 * when using the constant t_delta = t_gran / 2 = %USEC_PER_SEC / (2 * HZ).
57 */
58 #if (HZ >= 500)
59 # define TFRC_T_DELTA USEC_PER_MSEC
60 #else
61 # define TFRC_T_DELTA (USEC_PER_SEC / (2 * HZ))
62 #endif
63
64 enum ccid3_options {
65 TFRC_OPT_LOSS_EVENT_RATE = 192,
66 TFRC_OPT_LOSS_INTERVALS = 193,
67 TFRC_OPT_RECEIVE_RATE = 194,
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 };
76
77 /**
78 * struct ccid3_hc_tx_sock - CCID3 sender half-connection socket
79 * @tx_x: Current sending rate in 64 * bytes per second
80 * @tx_x_recv: Receive rate in 64 * bytes per second
81 * @tx_x_calc: Calculated rate in bytes per second
82 * @tx_rtt: Estimate of current round trip time in usecs
83 * @tx_p: Current loss event rate (0-1) scaled by 1000000
84 * @tx_s: Packet size in bytes
85 * @tx_t_rto: Nofeedback Timer setting in usecs
86 * @tx_t_ipi: Interpacket (send) interval (RFC 3448, 4.6) in usecs
87 * @tx_state: Sender state, one of %ccid3_hc_tx_states
88 * @tx_last_win_count: Last window counter sent
89 * @tx_t_last_win_count: Timestamp of earliest packet
90 * with last_win_count value sent
91 * @tx_no_feedback_timer: Handle to no feedback timer
92 * @tx_t_ld: Time last doubled during slow start
93 * @tx_t_nom: Nominal send time of next packet
94 * @tx_hist: Packet history
95 */
96 struct ccid3_hc_tx_sock {
97 u64 tx_x;
98 u64 tx_x_recv;
99 u32 tx_x_calc;
100 u32 tx_rtt;
101 u32 tx_p;
102 u32 tx_t_rto;
103 u32 tx_t_ipi;
104 u16 tx_s;
105 enum ccid3_hc_tx_states tx_state:8;
106 u8 tx_last_win_count;
107 ktime_t tx_t_last_win_count;
108 struct timer_list tx_no_feedback_timer;
109 ktime_t tx_t_ld;
110 ktime_t tx_t_nom;
111 struct tfrc_tx_hist_entry *tx_hist;
112 };
113
ccid3_hc_tx_sk(const struct sock * sk)114 static inline struct ccid3_hc_tx_sock *ccid3_hc_tx_sk(const struct sock *sk)
115 {
116 struct ccid3_hc_tx_sock *hctx = ccid_priv(dccp_sk(sk)->dccps_hc_tx_ccid);
117 BUG_ON(hctx == NULL);
118 return hctx;
119 }
120
121 /* TFRC receiver states */
122 enum ccid3_hc_rx_states {
123 TFRC_RSTATE_NO_DATA = 1,
124 TFRC_RSTATE_DATA,
125 };
126
127 /**
128 * struct ccid3_hc_rx_sock - CCID3 receiver half-connection socket
129 * @rx_last_counter: Tracks window counter (RFC 4342, 8.1)
130 * @rx_state: Receiver state, one of %ccid3_hc_rx_states
131 * @rx_bytes_recv: Total sum of DCCP payload bytes
132 * @rx_x_recv: Receiver estimate of send rate (RFC 3448, sec. 4.3)
133 * @rx_rtt: Receiver estimate of RTT
134 * @rx_tstamp_last_feedback: Time at which last feedback was sent
135 * @rx_hist: Packet history (loss detection + RTT sampling)
136 * @rx_li_hist: Loss Interval database
137 * @rx_s: Received packet size in bytes
138 * @rx_pinv: Inverse of Loss Event Rate (RFC 4342, sec. 8.5)
139 */
140 struct ccid3_hc_rx_sock {
141 u8 rx_last_counter:4;
142 enum ccid3_hc_rx_states rx_state:8;
143 u32 rx_bytes_recv;
144 u32 rx_x_recv;
145 u32 rx_rtt;
146 ktime_t rx_tstamp_last_feedback;
147 struct tfrc_rx_hist rx_hist;
148 struct tfrc_loss_hist rx_li_hist;
149 u16 rx_s;
150 #define rx_pinv rx_li_hist.i_mean
151 };
152
ccid3_hc_rx_sk(const struct sock * sk)153 static inline struct ccid3_hc_rx_sock *ccid3_hc_rx_sk(const struct sock *sk)
154 {
155 struct ccid3_hc_rx_sock *hcrx = ccid_priv(dccp_sk(sk)->dccps_hc_rx_ccid);
156 BUG_ON(hcrx == NULL);
157 return hcrx;
158 }
159
160 #endif /* _DCCP_CCID3_H_ */
161