[TFRC]: Provide central source file and debug facility
[linux-2.6.git] / net / dccp / ccids / lib / packet_history.h
1 /*
2  *  Packet RX/TX history data structures and routines for TFRC-based protocols.
3  *
4  *  Copyright (c) 2007   The University of Aberdeen, Scotland, UK
5  *  Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand.
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
36 #ifndef _DCCP_PKT_HIST_
37 #define _DCCP_PKT_HIST_
38
39 #include <linux/ktime.h>
40 #include <linux/list.h>
41 #include <linux/slab.h>
42 #include "tfrc.h"
43
44 /* Number of later packets received before one is considered lost */
45 #define TFRC_RECV_NUM_LATE_LOSS  3
46
47 #define TFRC_WIN_COUNT_PER_RTT   4
48 #define TFRC_WIN_COUNT_LIMIT    16
49
50 struct tfrc_tx_hist_entry;
51
52 extern int  tfrc_tx_hist_add(struct tfrc_tx_hist_entry **headp, u64 seqno);
53 extern void tfrc_tx_hist_purge(struct tfrc_tx_hist_entry **headp);
54 extern u32  tfrc_tx_hist_rtt(struct tfrc_tx_hist_entry *head,
55                              const u64 seqno, const ktime_t now);
56
57 /*
58  *      Receiver History data structures and declarations
59  */
60 struct dccp_rx_hist_entry {
61         struct list_head dccphrx_node;
62         u64              dccphrx_seqno:48,
63                          dccphrx_ccval:4,
64                          dccphrx_type:4;
65         u32              dccphrx_ndp; /* In fact it is from 8 to 24 bits */
66         ktime_t          dccphrx_tstamp;
67 };
68
69 struct dccp_rx_hist {
70         struct kmem_cache *dccprxh_slab;
71 };
72
73 extern struct dccp_rx_hist *dccp_rx_hist_new(const char *name);
74 extern void             dccp_rx_hist_delete(struct dccp_rx_hist *hist);
75
76 static inline struct dccp_rx_hist_entry *
77                         dccp_rx_hist_entry_new(struct dccp_rx_hist *hist,
78                                                const u32 ndp,
79                                                const struct sk_buff *skb,
80                                                const gfp_t prio)
81 {
82         struct dccp_rx_hist_entry *entry = kmem_cache_alloc(hist->dccprxh_slab,
83                                                             prio);
84
85         if (entry != NULL) {
86                 const struct dccp_hdr *dh = dccp_hdr(skb);
87
88                 entry->dccphrx_seqno = DCCP_SKB_CB(skb)->dccpd_seq;
89                 entry->dccphrx_ccval = dh->dccph_ccval;
90                 entry->dccphrx_type  = dh->dccph_type;
91                 entry->dccphrx_ndp   = ndp;
92                 entry->dccphrx_tstamp = ktime_get_real();
93         }
94
95         return entry;
96 }
97
98 static inline struct dccp_rx_hist_entry *
99                         dccp_rx_hist_head(struct list_head *list)
100 {
101         struct dccp_rx_hist_entry *head = NULL;
102
103         if (!list_empty(list))
104                 head = list_entry(list->next, struct dccp_rx_hist_entry,
105                                   dccphrx_node);
106         return head;
107 }
108
109 extern int dccp_rx_hist_find_entry(const struct list_head *list, const u64 seq,
110                                    u8 *ccval);
111 extern struct dccp_rx_hist_entry *
112                 dccp_rx_hist_find_data_packet(const struct list_head *list);
113
114 extern void dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
115                                     struct list_head *rx_list,
116                                     struct list_head *li_list,
117                                     struct dccp_rx_hist_entry *packet,
118                                     u64 nonloss_seqno);
119
120 static inline void dccp_rx_hist_entry_delete(struct dccp_rx_hist *hist,
121                                              struct dccp_rx_hist_entry *entry)
122 {
123         if (entry != NULL)
124                 kmem_cache_free(hist->dccprxh_slab, entry);
125 }
126
127 extern void dccp_rx_hist_purge(struct dccp_rx_hist *hist,
128                                struct list_head *list);
129
130 static inline int
131         dccp_rx_hist_entry_data_packet(const struct dccp_rx_hist_entry *entry)
132 {
133         return entry->dccphrx_type == DCCP_PKT_DATA ||
134                entry->dccphrx_type == DCCP_PKT_DATAACK;
135 }
136
137 extern u64 dccp_rx_hist_detect_loss(struct list_head *rx_list,
138                                     struct list_head *li_list, u8 *win_loss);
139
140 #endif /* _DCCP_PKT_HIST_ */