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  *
15  *     This program is free software; you can redistribute it and/or
16  *     modify it under the terms of the GNU General Public License as
17  *     published by the Free Software Foundation; either version 2 of
18  *     the License, or (at your option) any later version.
19  *
20  *     Neither Dag Brattli nor University of Troms� admit liability nor
21  *     provide warranty for any of this software. This material is
22  *     provided "AS-IS" and at no charge.
23  *
24  ********************************************************************/
25 
26 #ifndef IRTTP_H
27 #define IRTTP_H
28 
29 #include <linux/types.h>
30 #include <linux/skbuff.h>
31 #include <linux/spinlock.h>
32 
33 #include <net/irda/irda.h>
34 #include <net/irda/irlmp.h>
35 #include <net/irda/qos.h>
36 #include <net/irda/irqueue.h>
37 
38 #define TTP_MAX_CONNECTIONS    LM_MAX_CONNECTIONS
39 #define TTP_HEADER             1
40 #define TTP_MAX_HEADER         (TTP_HEADER + LMP_MAX_HEADER)
41 #define TTP_SAR_HEADER         5
42 #define TTP_PARAMETERS         0x80
43 #define TTP_MORE               0x80
44 
45 /* Transmission queue sizes */
46 /* Worst case scenario, two window of data - Jean II */
47 #define TTP_TX_MAX_QUEUE	14
48 /* We need to keep at least 5 frames to make sure that we can refill
49  * appropriately the LAP layer. LAP keeps only two buffers, and we need
50  * to have 7 to make a full window - Jean II */
51 #define TTP_TX_LOW_THRESHOLD	5
52 /* Most clients are synchronous with respect to flow control, so we can
53  * keep a low number of Tx buffers in TTP - Jean II */
54 #define TTP_TX_HIGH_THRESHOLD	7
55 
56 /* Receive queue sizes */
57 /* Minimum of credit that the peer should hold.
58  * If the peer has less credits than 9 frames, we will explicitely send
59  * him some credits (through irttp_give_credit() and a specific frame).
60  * Note that when we give credits it's likely that it won't be sent in
61  * this LAP window, but in the next one. So, we make sure that the peer
62  * has something to send while waiting for credits (one LAP window == 7
63  * + 1 frames while he process the credits). - Jean II */
64 #define TTP_RX_MIN_CREDIT	8
65 /* This is the default maximum number of credits held by the peer, so the
66  * default maximum number of frames he can send us before needing flow
67  * control answer from us (this may be negociated differently at TSAP setup).
68  * We want to minimise the number of times we have to explicitely send some
69  * credit to the peer, hoping we can piggyback it on the return data. In
70  * particular, it doesn't make sense for us to send credit more than once
71  * per LAP window.
72  * Moreover, giving credits has some latency, so we need strictly more than
73  * a LAP window, otherwise we may already have credits in our Tx queue.
74  * But on the other hand, we don't want to keep too many Rx buffer here
75  * before starting to flow control the other end, so make it exactly one
76  * LAP window + 1 + MIN_CREDITS. - Jean II */
77 #define TTP_RX_DEFAULT_CREDIT	16
78 /* Maximum number of credits we can allow the peer to have, and therefore
79  * maximum Rx queue size.
80  * Note that we try to deliver packets to the higher layer every time we
81  * receive something, so in normal mode the Rx queue will never contains
82  * more than one or two packets. - Jean II */
83 #define TTP_RX_MAX_CREDIT	21
84 
85 /* What clients should use when calling ttp_open_tsap() */
86 #define DEFAULT_INITIAL_CREDIT	TTP_RX_DEFAULT_CREDIT
87 
88 /* Some priorities for disconnect requests */
89 #define P_NORMAL    0
90 #define P_HIGH      1
91 
92 #define TTP_SAR_DISABLE 0
93 #define TTP_SAR_UNBOUND 0xffffffff
94 
95 /* Parameters */
96 #define TTP_MAX_SDU_SIZE 0x01
97 
98 /*
99  *  This structure contains all data assosiated with one instance of a TTP
100  *  connection.
101  */
102 struct tsap_cb {
103 	irda_queue_t q;            /* Must be first */
104 	magic_t magic;        /* Just in case */
105 
106 	__u8 stsap_sel;       /* Source TSAP */
107 	__u8 dtsap_sel;       /* Destination TSAP */
108 
109 	struct lsap_cb *lsap; /* Corresponding LSAP to this TSAP */
110 
111 	__u8 connected;       /* TSAP connected */
112 
113 	__u8 initial_credit;  /* Initial credit to give peer */
114 
115         int avail_credit;    /* Available credit to return to peer */
116 	int remote_credit;   /* Credit held by peer TTP entity */
117 	int send_credit;     /* Credit held by local TTP entity */
118 
119 	struct sk_buff_head tx_queue; /* Frames to be transmitted */
120 	struct sk_buff_head rx_queue; /* Received frames */
121 	struct sk_buff_head rx_fragments;
122 	int tx_queue_lock;
123 	int rx_queue_lock;
124 	spinlock_t lock;
125 
126 	notify_t notify;       /* Callbacks to client layer */
127 
128 	struct net_device_stats stats;
129 	struct timer_list todo_timer;
130 
131 	__u32 max_seg_size;     /* Max data that fit into an IrLAP frame */
132 	__u8  max_header_size;
133 
134 	int   rx_sdu_busy;     /* RxSdu.busy */
135 	__u32 rx_sdu_size;     /* Current size of a partially received frame */
136 	__u32 rx_max_sdu_size; /* Max receive user data size */
137 
138 	int tx_sdu_busy;       /* TxSdu.busy */
139 	__u32 tx_max_sdu_size; /* Max transmit user data size */
140 
141 	int close_pend;        /* Close, but disconnect_pend */
142 	int disconnect_pend;   /* Disconnect, but still data to send */
143 	struct sk_buff *disconnect_skb;
144 };
145 
146 struct irttp_cb {
147 	magic_t    magic;
148 	hashbin_t *tsaps;
149 };
150 
151 int  irttp_init(void);
152 void irttp_cleanup(void);
153 
154 struct tsap_cb *irttp_open_tsap(__u8 stsap_sel, int credit, notify_t *notify);
155 int irttp_close_tsap(struct tsap_cb *self);
156 
157 int irttp_data_request(struct tsap_cb *self, struct sk_buff *skb);
158 int irttp_udata_request(struct tsap_cb *self, struct sk_buff *skb);
159 
160 int irttp_connect_request(struct tsap_cb *self, __u8 dtsap_sel,
161 			  __u32 saddr, __u32 daddr,
162 			  struct qos_info *qos, __u32 max_sdu_size,
163 			  struct sk_buff *userdata);
164 int irttp_connect_response(struct tsap_cb *self, __u32 max_sdu_size,
165 			    struct sk_buff *userdata);
166 int irttp_disconnect_request(struct tsap_cb *self, struct sk_buff *skb,
167 			     int priority);
168 void irttp_flow_request(struct tsap_cb *self, LOCAL_FLOW flow);
169 void irttp_status_indication(void *instance,
170 			     LINK_STATUS link, LOCK_STATUS lock);
171 void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow);
172 struct tsap_cb *irttp_dup(struct tsap_cb *self, void *instance);
173 
irttp_get_saddr(struct tsap_cb * self)174 static __inline __u32 irttp_get_saddr(struct tsap_cb *self)
175 {
176 	return irlmp_get_saddr(self->lsap);
177 }
178 
irttp_get_daddr(struct tsap_cb * self)179 static __inline __u32 irttp_get_daddr(struct tsap_cb *self)
180 {
181 	return irlmp_get_daddr(self->lsap);
182 }
183 
irttp_get_max_seg_size(struct tsap_cb * self)184 static __inline __u32 irttp_get_max_seg_size(struct tsap_cb *self)
185 {
186 	return self->max_seg_size;
187 }
188 
189 /* After doing a irttp_dup(), this get one of the two socket back into
190  * a state where it's waiting incomming connections.
191  * Note : this can be used *only* if the socket is not yet connected
192  * (i.e. NO irttp_connect_response() done on this socket).
193  * - Jean II */
irttp_listen(struct tsap_cb * self)194 static inline void irttp_listen(struct tsap_cb *self)
195 {
196 	irlmp_listen(self->lsap);
197 	self->dtsap_sel = LSAP_ANY;
198 }
199 
200 /* Return TRUE if the node is in primary mode (i.e. master)
201  * - Jean II */
irttp_is_primary(struct tsap_cb * self)202 static inline int irttp_is_primary(struct tsap_cb *self)
203 {
204 	if ((self == NULL) ||
205 	    (self->lsap == NULL) ||
206 	    (self->lsap->lap == NULL) ||
207 	    (self->lsap->lap->irlap == NULL))
208 		return -2;
209 	return(irlap_is_primary(self->lsap->lap->irlap));
210 }
211 
212 #endif /* IRTTP_H */
213