1 /*
2  *  net/dccp/packet_history.h
3  *
4  *  Copyright (c) 2005 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 - iam4@cs.waikato.ac.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/config.h>
41 #include <linux/list.h>
42 #include <linux/slab.h>
43 #include <linux/time.h>
44 
45 #include "../../dccp.h"
46 
47 /* Number of later packets received before one is considered lost */
48 #define TFRC_RECV_NUM_LATE_LOSS	 3
49 
50 #define TFRC_WIN_COUNT_PER_RTT	 4
51 #define TFRC_WIN_COUNT_LIMIT	16
52 
53 struct dccp_tx_hist_entry {
54 	struct list_head dccphtx_node;
55 	u64		 dccphtx_seqno:48,
56 			 dccphtx_ccval:4,
57 			 dccphtx_sent:1;
58 	u32		 dccphtx_rtt;
59 	struct timeval	 dccphtx_tstamp;
60 };
61 
62 struct dccp_rx_hist_entry {
63 	struct list_head dccphrx_node;
64 	u64		 dccphrx_seqno:48,
65 			 dccphrx_ccval:4,
66 			 dccphrx_type:4;
67 	u32		 dccphrx_ndp; /* In fact it is from 8 to 24 bits */
68 	struct timeval	 dccphrx_tstamp;
69 };
70 
71 struct dccp_tx_hist {
72 	kmem_cache_t *dccptxh_slab;
73 };
74 
75 extern struct dccp_tx_hist *dccp_tx_hist_new(const char *name);
76 extern void dccp_tx_hist_delete(struct dccp_tx_hist *hist);
77 
78 struct dccp_rx_hist {
79 	kmem_cache_t *dccprxh_slab;
80 };
81 
82 extern struct dccp_rx_hist *dccp_rx_hist_new(const char *name);
83 extern void dccp_rx_hist_delete(struct dccp_rx_hist *hist);
84 extern struct dccp_rx_hist_entry *
85 		dccp_rx_hist_find_data_packet(const struct list_head *list);
86 
87 static inline struct dccp_tx_hist_entry *
88 		dccp_tx_hist_entry_new(struct dccp_tx_hist *hist,
89 				       const gfp_t prio)
90 {
91 	struct dccp_tx_hist_entry *entry = kmem_cache_alloc(hist->dccptxh_slab,
92 							    prio);
93 
94 	if (entry != NULL)
95 		entry->dccphtx_sent = 0;
96 
97 	return entry;
98 }
99 
100 static inline void dccp_tx_hist_entry_delete(struct dccp_tx_hist *hist,
101 					     struct dccp_tx_hist_entry *entry)
102 {
103 	if (entry != NULL)
104 		kmem_cache_free(hist->dccptxh_slab, entry);
105 }
106 
107 extern struct dccp_tx_hist_entry *
108 			dccp_tx_hist_find_entry(const struct list_head *list,
109 						const u64 seq);
110 
111 static inline void dccp_tx_hist_add_entry(struct list_head *list,
112 					  struct dccp_tx_hist_entry *entry)
113 {
114 	list_add(&entry->dccphtx_node, list);
115 }
116 
117 extern void dccp_tx_hist_purge_older(struct dccp_tx_hist *hist,
118 				     struct list_head *list,
119 				     struct dccp_tx_hist_entry *next);
120 
121 extern void dccp_tx_hist_purge(struct dccp_tx_hist *hist,
122 			       struct list_head *list);
123 
124 static inline struct dccp_tx_hist_entry *
125 		dccp_tx_hist_head(struct list_head *list)
126 {
127 	struct dccp_tx_hist_entry *head = NULL;
128 
129 	if (!list_empty(list))
130 		head = list_entry(list->next, struct dccp_tx_hist_entry,
131 				  dccphtx_node);
132 	return head;
133 }
134 
135 static inline struct dccp_rx_hist_entry *
136 		     dccp_rx_hist_entry_new(struct dccp_rx_hist *hist,
137 				     	    const struct sock *sk,
138 				     	    const u32 ndp,
139 					    const struct sk_buff *skb,
140 					    const gfp_t prio)
141 {
142 	struct dccp_rx_hist_entry *entry = kmem_cache_alloc(hist->dccprxh_slab,
143 							    prio);
144 
145 	if (entry != NULL) {
146 		const struct dccp_hdr *dh = dccp_hdr(skb);
147 
148 		entry->dccphrx_seqno = DCCP_SKB_CB(skb)->dccpd_seq;
149 		entry->dccphrx_ccval = dh->dccph_ccval;
150 		entry->dccphrx_type  = dh->dccph_type;
151 		entry->dccphrx_ndp   = ndp;
152 		dccp_timestamp(sk, &entry->dccphrx_tstamp);
153 	}
154 
155 	return entry;
156 }
157 
158 static inline void dccp_rx_hist_entry_delete(struct dccp_rx_hist *hist,
159 					     struct dccp_rx_hist_entry *entry)
160 {
161 	if (entry != NULL)
162 		kmem_cache_free(hist->dccprxh_slab, entry);
163 }
164 
165 extern void dccp_rx_hist_purge(struct dccp_rx_hist *hist,
166 			       struct list_head *list);
167 
168 static inline void dccp_rx_hist_add_entry(struct list_head *list,
169 					  struct dccp_rx_hist_entry *entry)
170 {
171 	list_add(&entry->dccphrx_node, list);
172 }
173 
174 static inline struct dccp_rx_hist_entry *
175 		dccp_rx_hist_head(struct list_head *list)
176 {
177 	struct dccp_rx_hist_entry *head = NULL;
178 
179 	if (!list_empty(list))
180 		head = list_entry(list->next, struct dccp_rx_hist_entry,
181 				  dccphrx_node);
182 	return head;
183 }
184 
185 static inline int
186 	dccp_rx_hist_entry_data_packet(const struct dccp_rx_hist_entry *entry)
187 {
188 	return entry->dccphrx_type == DCCP_PKT_DATA ||
189 	       entry->dccphrx_type == DCCP_PKT_DATAACK;
190 }
191 
192 extern int dccp_rx_hist_add_packet(struct dccp_rx_hist *hist,
193 				   struct list_head *rx_list,
194 				   struct list_head *li_list,
195 				   struct dccp_rx_hist_entry *packet);
196 
197 extern u64 dccp_rx_hist_detect_loss(struct list_head *rx_list,
198 				    struct list_head *li_list, u8 *win_loss);
199 
200 #endif /* _DCCP_PKT_HIST_ */
201