1 /*
2  *  net/dccp/packet_history.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 
37 #ifndef _DCCP_PKT_HIST_
38 #define _DCCP_PKT_HIST_
39 
40 #include <linux/list.h>
41 #include <linux/slab.h>
42 #include <linux/time.h>
43 
44 #include "../../dccp.h"
45 
46 /* Number of later packets received before one is considered lost */
47 #define TFRC_RECV_NUM_LATE_LOSS	 3
48 
49 #define TFRC_WIN_COUNT_PER_RTT	 4
50 #define TFRC_WIN_COUNT_LIMIT	16
51 
52 /*
53  * 	Transmitter History data structures and declarations
54  */
55 struct dccp_tx_hist_entry {
56 	struct list_head dccphtx_node;
57 	u64		 dccphtx_seqno:48,
58 			 dccphtx_sent:1;
59 	u32		 dccphtx_rtt;
60 	struct timeval	 dccphtx_tstamp;
61 };
62 
63 struct dccp_tx_hist {
64 	struct kmem_cache *dccptxh_slab;
65 };
66 
67 extern struct dccp_tx_hist *dccp_tx_hist_new(const char *name);
68 extern void 		    dccp_tx_hist_delete(struct dccp_tx_hist *hist);
69 
70 static inline struct dccp_tx_hist_entry *
71 			dccp_tx_hist_entry_new(struct dccp_tx_hist *hist,
72 					       const gfp_t prio)
73 {
74 	struct dccp_tx_hist_entry *entry = kmem_cache_alloc(hist->dccptxh_slab,
75 							    prio);
76 
77 	if (entry != NULL)
78 		entry->dccphtx_sent = 0;
79 
80 	return entry;
81 }
82 
83 static inline struct dccp_tx_hist_entry *
84 			dccp_tx_hist_head(struct list_head *list)
85 {
86 	struct dccp_tx_hist_entry *head = NULL;
87 
88 	if (!list_empty(list))
89 		head = list_entry(list->next, struct dccp_tx_hist_entry,
90 				  dccphtx_node);
91 	return head;
92 }
93 
94 extern struct dccp_tx_hist_entry *
95 			dccp_tx_hist_find_entry(const struct list_head *list,
96 						const u64 seq);
97 
98 static inline void dccp_tx_hist_add_entry(struct list_head *list,
99 					  struct dccp_tx_hist_entry *entry)
100 {
101 	list_add(&entry->dccphtx_node, list);
102 }
103 
104 static inline void dccp_tx_hist_entry_delete(struct dccp_tx_hist *hist,
105 					     struct dccp_tx_hist_entry *entry)
106 {
107 	if (entry != NULL)
108 		kmem_cache_free(hist->dccptxh_slab, entry);
109 }
110 
111 extern void dccp_tx_hist_purge(struct dccp_tx_hist *hist,
112 			       struct list_head *list);
113 
114 extern void dccp_tx_hist_purge_older(struct dccp_tx_hist *hist,
115 				     struct list_head *list,
116 				     struct dccp_tx_hist_entry *next);
117 
118 /*
119  * 	Receiver History data structures and declarations
120  */
121 struct dccp_rx_hist_entry {
122 	struct list_head dccphrx_node;
123 	u64		 dccphrx_seqno:48,
124 			 dccphrx_ccval:4,
125 			 dccphrx_type:4;
126 	u32		 dccphrx_ndp; /* In fact it is from 8 to 24 bits */
127 	struct timeval	 dccphrx_tstamp;
128 };
129 
130 struct dccp_rx_hist {
131 	struct kmem_cache *dccprxh_slab;
132 };
133 
134 extern struct dccp_rx_hist *dccp_rx_hist_new(const char *name);
135 extern void 		dccp_rx_hist_delete(struct dccp_rx_hist *hist);
136 
137 static inline struct dccp_rx_hist_entry *
138 			dccp_rx_hist_entry_new(struct dccp_rx_hist *hist,
139 					       const struct sock *sk,
140 					       const u32 ndp,
141 					       const struct sk_buff *skb,
142 					       const gfp_t prio)
143 {
144 	struct dccp_rx_hist_entry *entry = kmem_cache_alloc(hist->dccprxh_slab,
145 							    prio);
146 
147 	if (entry != NULL) {
148 		const struct dccp_hdr *dh = dccp_hdr(skb);
149 
150 		entry->dccphrx_seqno = DCCP_SKB_CB(skb)->dccpd_seq;
151 		entry->dccphrx_ccval = dh->dccph_ccval;
152 		entry->dccphrx_type  = dh->dccph_type;
153 		entry->dccphrx_ndp   = ndp;
154 		dccp_timestamp(sk, &entry->dccphrx_tstamp);
155 	}
156 
157 	return entry;
158 }
159 
160 static inline struct dccp_rx_hist_entry *
161 			dccp_rx_hist_head(struct list_head *list)
162 {
163 	struct dccp_rx_hist_entry *head = NULL;
164 
165 	if (!list_empty(list))
166 		head = list_entry(list->next, struct dccp_rx_hist_entry,
167 				  dccphrx_node);
168 	return head;
169 }
170 
171 extern int dccp_rx_hist_find_entry(const struct list_head *list, const u64 seq,
172 				   u8 *ccval);
173 extern struct dccp_rx_hist_entry *
174 		dccp_rx_hist_find_data_packet(const struct list_head *list);
175 
176 extern void dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
177 				    struct list_head *rx_list,
178 				    struct list_head *li_list,
179 				    struct dccp_rx_hist_entry *packet,
180 				    u64 nonloss_seqno);
181 
182 static inline void dccp_rx_hist_entry_delete(struct dccp_rx_hist *hist,
183 					     struct dccp_rx_hist_entry *entry)
184 {
185 	if (entry != NULL)
186 		kmem_cache_free(hist->dccprxh_slab, entry);
187 }
188 
189 extern void dccp_rx_hist_purge(struct dccp_rx_hist *hist,
190 			       struct list_head *list);
191 
192 static inline int
193 	dccp_rx_hist_entry_data_packet(const struct dccp_rx_hist_entry *entry)
194 {
195 	return entry->dccphrx_type == DCCP_PKT_DATA ||
196 	       entry->dccphrx_type == DCCP_PKT_DATAACK;
197 }
198 
199 extern u64 dccp_rx_hist_detect_loss(struct list_head *rx_list,
200 				    struct list_head *li_list, u8 *win_loss);
201 
202 #endif /* _DCCP_PKT_HIST_ */
203