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irttp.h
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1 /*********************************************************************
2  *
3  * Filename: irttp.h
4  * Version: 1.0
5  * Description: Tiny Transport Protocol (TTP) definitions
6  * Status: Experimental.
7  * Author: Dag Brattli <[email protected]>
8  * Created at: Sun Aug 31 20:14:31 1997
9  * Modified at: Sun Dec 12 13:09:07 1999
10  * Modified by: Dag Brattli <[email protected]>
11  *
12  * Copyright (c) 1998-1999 Dag Brattli <[email protected]>,
13  * All Rights Reserved.
14  * Copyright (c) 2000-2002 Jean Tourrilhes <[email protected]>
15  *
16  * This program is free software; you can redistribute it and/or
17  * modify it under the terms of the GNU General Public License as
18  * published by the Free Software Foundation; either version 2 of
19  * the License, or (at your option) any later version.
20  *
21  * Neither Dag Brattli nor University of Tromsø admit liability nor
22  * provide warranty for any of this software. This material is
23  * provided "AS-IS" and at no charge.
24  *
25  ********************************************************************/
26 
27 #ifndef IRTTP_H
28 #define IRTTP_H
29 
30 #include <linux/types.h>
31 #include <linux/skbuff.h>
32 #include <linux/spinlock.h>
33 
34 #include <net/irda/irda.h>
35 #include <net/irda/irlmp.h> /* struct lsap_cb */
36 #include <net/irda/qos.h> /* struct qos_info */
37 #include <net/irda/irqueue.h>
38 
39 #define TTP_MAX_CONNECTIONS LM_MAX_CONNECTIONS
40 #define TTP_HEADER 1
41 #define TTP_MAX_HEADER (TTP_HEADER + LMP_MAX_HEADER)
42 #define TTP_SAR_HEADER 5
43 #define TTP_PARAMETERS 0x80
44 #define TTP_MORE 0x80
45 
46 /* Transmission queue sizes */
47 /* Worst case scenario, two window of data - Jean II */
48 #define TTP_TX_MAX_QUEUE 14
49 /* We need to keep at least 5 frames to make sure that we can refill
50  * appropriately the LAP layer. LAP keeps only two buffers, and we need
51  * to have 7 to make a full window - Jean II */
52 #define TTP_TX_LOW_THRESHOLD 5
53 /* Most clients are synchronous with respect to flow control, so we can
54  * keep a low number of Tx buffers in TTP - Jean II */
55 #define TTP_TX_HIGH_THRESHOLD 7
56 
57 /* Receive queue sizes */
58 /* Minimum of credit that the peer should hold.
59  * If the peer has less credits than 9 frames, we will explicitly send
60  * him some credits (through irttp_give_credit() and a specific frame).
61  * Note that when we give credits it's likely that it won't be sent in
62  * this LAP window, but in the next one. So, we make sure that the peer
63  * has something to send while waiting for credits (one LAP window == 7
64  * + 1 frames while he process the credits). - Jean II */
65 #define TTP_RX_MIN_CREDIT 8
66 /* This is the default maximum number of credits held by the peer, so the
67  * default maximum number of frames he can send us before needing flow
68  * control answer from us (this may be negociated differently at TSAP setup).
69  * We want to minimise the number of times we have to explicitly send some
70  * credit to the peer, hoping we can piggyback it on the return data. In
71  * particular, it doesn't make sense for us to send credit more than once
72  * per LAP window.
73  * Moreover, giving credits has some latency, so we need strictly more than
74  * a LAP window, otherwise we may already have credits in our Tx queue.
75  * But on the other hand, we don't want to keep too many Rx buffer here
76  * before starting to flow control the other end, so make it exactly one
77  * LAP window + 1 + MIN_CREDITS. - Jean II */
78 #define TTP_RX_DEFAULT_CREDIT 16
79 /* Maximum number of credits we can allow the peer to have, and therefore
80  * maximum Rx queue size.
81  * Note that we try to deliver packets to the higher layer every time we
82  * receive something, so in normal mode the Rx queue will never contains
83  * more than one or two packets. - Jean II */
84 #define TTP_RX_MAX_CREDIT 21
85 
86 /* What clients should use when calling ttp_open_tsap() */
87 #define DEFAULT_INITIAL_CREDIT TTP_RX_DEFAULT_CREDIT
88 
89 /* Some priorities for disconnect requests */
90 #define P_NORMAL 0
91 #define P_HIGH 1
92 
93 #define TTP_SAR_DISABLE 0
94 #define TTP_SAR_UNBOUND 0xffffffff
95 
96 /* Parameters */
97 #define TTP_MAX_SDU_SIZE 0x01
98 
99 /*
100  * This structure contains all data associated with one instance of a TTP
101  * connection.
102  */
103 struct tsap_cb {
104  irda_queue_t q; /* Must be first */
105  magic_t magic; /* Just in case */
106 
107  __u8 stsap_sel; /* Source TSAP */
108  __u8 dtsap_sel; /* Destination TSAP */
109 
110  struct lsap_cb *lsap; /* Corresponding LSAP to this TSAP */
111 
112  __u8 connected; /* TSAP connected */
113 
114  __u8 initial_credit; /* Initial credit to give peer */
115 
116  int avail_credit; /* Available credit to return to peer */
117  int remote_credit; /* Credit held by peer TTP entity */
118  int send_credit; /* Credit held by local TTP entity */
119 
120  struct sk_buff_head tx_queue; /* Frames to be transmitted */
121  struct sk_buff_head rx_queue; /* Received frames */
126 
127  notify_t notify; /* Callbacks to client layer */
128 
131 
132  __u32 max_seg_size; /* Max data that fit into an IrLAP frame */
134 
135  int rx_sdu_busy; /* RxSdu.busy */
136  __u32 rx_sdu_size; /* Current size of a partially received frame */
137  __u32 rx_max_sdu_size; /* Max receive user data size */
138 
139  int tx_sdu_busy; /* TxSdu.busy */
140  __u32 tx_max_sdu_size; /* Max transmit user data size */
141 
142  int close_pend; /* Close, but disconnect_pend */
143  unsigned long disconnect_pend; /* Disconnect, but still data to send */
145 };
146 
147 struct irttp_cb {
150 };
151 
152 int irttp_init(void);
153 void irttp_cleanup(void);
154 
155 struct tsap_cb *irttp_open_tsap(__u8 stsap_sel, int credit, notify_t *notify);
156 int irttp_close_tsap(struct tsap_cb *self);
157 
158 int irttp_data_request(struct tsap_cb *self, struct sk_buff *skb);
159 int irttp_udata_request(struct tsap_cb *self, struct sk_buff *skb);
160 
161 int irttp_connect_request(struct tsap_cb *self, __u8 dtsap_sel,
163  struct qos_info *qos, __u32 max_sdu_size,
164  struct sk_buff *userdata);
165 int irttp_connect_response(struct tsap_cb *self, __u32 max_sdu_size,
166  struct sk_buff *userdata);
167 int irttp_disconnect_request(struct tsap_cb *self, struct sk_buff *skb,
168  int priority);
169 void irttp_flow_request(struct tsap_cb *self, LOCAL_FLOW flow);
170 struct tsap_cb *irttp_dup(struct tsap_cb *self, void *instance);
171 
172 static inline __u32 irttp_get_saddr(struct tsap_cb *self)
173 {
174  return irlmp_get_saddr(self->lsap);
175 }
176 
177 static inline __u32 irttp_get_daddr(struct tsap_cb *self)
178 {
179  return irlmp_get_daddr(self->lsap);
180 }
181 
182 static inline __u32 irttp_get_max_seg_size(struct tsap_cb *self)
183 {
184  return self->max_seg_size;
185 }
186 
187 /* After doing a irttp_dup(), this get one of the two socket back into
188  * a state where it's waiting incomming connections.
189  * Note : this can be used *only* if the socket is not yet connected
190  * (i.e. NO irttp_connect_response() done on this socket).
191  * - Jean II */
192 static inline void irttp_listen(struct tsap_cb *self)
193 {
194  irlmp_listen(self->lsap);
195  self->dtsap_sel = LSAP_ANY;
196 }
197 
198 /* Return TRUE if the node is in primary mode (i.e. master)
199  * - Jean II */
200 static inline int irttp_is_primary(struct tsap_cb *self)
201 {
202  if ((self == NULL) ||
203  (self->lsap == NULL) ||
204  (self->lsap->lap == NULL) ||
205  (self->lsap->lap->irlap == NULL))
206  return -2;
207  return irlap_is_primary(self->lsap->lap->irlap);
208 }
209 
210 #endif /* IRTTP_H */