1 /*********************************************************************
2  *
3  * Filename:      irttp.h
4  * Version:       1.0
5  * Description:   Tiny Transport Protocol (TTP) definitions
6  * Status:        Experimental.
7  * Author:        Dag Brattli <dagb@cs.uit.no>
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 <dagb@cs.uit.no>
11  *
12  *     Copyright (c) 1998-1999 Dag Brattli <dagb@cs.uit.no>,
13  *     All Rights Reserved.
14  *     Copyright (c) 2000-2002 Jean Tourrilhes <jt@hpl.hp.com>
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 */
122 	struct sk_buff_head rx_fragments;
123 	int tx_queue_lock;
124 	int rx_queue_lock;
125 	spinlock_t lock;
126 
127 	notify_t notify;       /* Callbacks to client layer */
128 
129 	struct net_device_stats stats;
130 	struct timer_list todo_timer;
131 
132 	__u32 max_seg_size;     /* Max data that fit into an IrLAP frame */
133 	__u8  max_header_size;
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 */
144 	struct sk_buff *disconnect_skb;
145 };
146 
147 struct irttp_cb {
148 	magic_t    magic;
149 	hashbin_t *tsaps;
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,
162 			  __u32 saddr, __u32 daddr,
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 
irttp_get_saddr(struct tsap_cb * self)172 static inline __u32 irttp_get_saddr(struct tsap_cb *self)
173 {
174 	return irlmp_get_saddr(self->lsap);
175 }
176 
irttp_get_daddr(struct tsap_cb * self)177 static inline __u32 irttp_get_daddr(struct tsap_cb *self)
178 {
179 	return irlmp_get_daddr(self->lsap);
180 }
181 
irttp_get_max_seg_size(struct tsap_cb * self)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 */
irttp_listen(struct tsap_cb * self)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 */
irttp_is_primary(struct tsap_cb * self)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 */
211