1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
|
#ifndef _NET_DN_NSP_H
#define _NET_DN_NSP_H
/******************************************************************************
(c) 1995-1998 E.M. Serrat emserrat@geocities.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
*******************************************************************************/
/* dn_nsp.c functions prototyping */
extern void dn_nsp_send_data_ack(struct sock *sk);
extern void dn_nsp_send_oth_ack(struct sock *sk);
extern void dn_nsp_delayed_ack(struct sock *sk);
extern void dn_send_conn_ack(struct sock *sk);
extern void dn_send_conn_conf(struct sock *sk);
extern void dn_send_disc(struct sock *sk, unsigned char type, unsigned short reason);
extern void dn_nsp_send_lnk(struct sock *sk, unsigned short flags);
extern void dn_nsp_send_conninit(struct sock *sk, unsigned char flags);
extern void dn_nsp_output(struct sock *sk);
extern int dn_nsp_check_xmit_queue(struct sock *sk, struct sk_buff *skb, struct sk_buff_head *q, unsigned short acknum);
extern void dn_nsp_queue_xmit(struct sock *sk, struct sk_buff *skb, int oob);
extern unsigned long dn_nsp_persist(struct sock *sk);
extern int dn_nsp_xmit_timeout(struct sock *sk);
extern int dn_nsp_rx(struct sk_buff *);
extern int dn_nsp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
extern struct sk_buff *dn_alloc_skb(struct sock *sk, int size, int pri);
extern struct sk_buff *dn_alloc_send_skb(struct sock *sk, int *size, int noblock, int *err);
#define NSP_REASON_NR 1
#define NSP_REASON_DC 42
#define NSP_REASON_NL 41
#define NSP_DISCINIT 0x38
#define NSP_DISCCONF 0x48
/*------------------------- NSP - messages ------------------------------*/
/* Data Messages */
/*---------------*/
/* Data Messages (data segment/interrupt/link service) */
struct nsp_data_seg_msg
{
unsigned char msgflg __attribute__((packed));
unsigned short dstaddr __attribute__((packed));
unsigned short srcaddr __attribute__((packed));
};
struct nsp_data_opt_msg
{
unsigned short acknum __attribute__((packed));
unsigned short segnum __attribute__((packed));
unsigned short lsflgs __attribute__((packed));
};
struct nsp_data_opt_msg1
{
unsigned short acknum __attribute__((packed));
unsigned short segnum __attribute__((packed));
};
/* Acknowledgment Messages */
/*-------------------------*/
/* Acknowledgment Messages (data/other data) */
struct nsp_data_ack_msg
{
unsigned char msgflg __attribute__((packed));
unsigned short dstaddr __attribute__((packed));
unsigned short srcaddr __attribute__((packed));
unsigned short acknum __attribute__((packed));
};
/* Connect Acknowledgment Message */
struct nsp_conn_ack_msg
{
unsigned char msgflg __attribute__((packed));
unsigned short dstaddr __attribute__((packed));
};
/* Control Messages */
/*------------------*/
/* Connect Initiate/Retransmit Initiate/Connect Confirm */
struct nsp_conn_init_msg
{
unsigned char msgflg __attribute__((packed));
#define NSP_CI 0x18 /* Connect Initiate */
#define NSP_RCI 0x68 /* Retrans. Conn Init */
unsigned short dstaddr __attribute__((packed));
unsigned short srcaddr __attribute__((packed));
unsigned char services __attribute__((packed));
#define NSP_FC_NONE 0x00 /* Flow Control None */
#define NSP_FC_SRC 0x04 /* Seg Req. Count */
#define NSP_FC_SCMC 0x08 /* Sess. Control Mess */
unsigned char info __attribute__((packed));
unsigned short segsize __attribute__((packed));
};
/* Disconnect Initiate/Disconnect Confirm */
struct nsp_disconn_init_msg
{
unsigned char msgflg __attribute__((packed));
unsigned short dstaddr __attribute__((packed));
unsigned short srcaddr __attribute__((packed));
unsigned short reason __attribute__((packed));
};
/*------------------------- SCP - messages ------------------------------*/
struct srcobj_fmt
{
char format __attribute__((packed));
unsigned char task __attribute__((packed));
unsigned short grpcode __attribute__((packed));
unsigned short usrcode __attribute__((packed));
char dlen __attribute__((packed));
};
/*
* A collection of functions for manipulating the sequence
* numbers used in NSP. Similar in operation to the functions
* of the same name in TCP.
*/
static __inline__ int before(unsigned short seq1, unsigned short seq2)
{
seq1 &= 0x0fff;
seq2 &= 0x0fff;
return (int)((seq1 - seq2) & 0x0fff) > 2048;
}
static __inline__ int after(unsigned short seq1, unsigned short seq2)
{
seq1 &= 0x0fff;
seq2 &= 0x0fff;
return (int)((seq2 - seq1) & 0x0fff) > 2048;
}
static __inline__ int equal(unsigned short seq1, unsigned short seq2)
{
return ((seq1 ^ seq2) & 0x0fff) == 0;
}
static __inline__ int before_or_equal(unsigned short seq1, unsigned short seq2)
{
return (before(seq1, seq2) || equal(seq1, seq2));
}
static __inline__ void seq_add(unsigned short *seq, unsigned short off)
{
*seq += off;
*seq &= 0x0fff;
}
static __inline__ int seq_next(unsigned short seq1, unsigned short seq2)
{
return (((seq2&0x0fff) - (seq1&0x0fff)) == 1);
}
/*
* Can we delay the ack ?
*/
static __inline__ int sendack(unsigned short seq)
{
return (int)((seq & 0x1000) ? 0 : 1);
}
/*
* Is socket congested ?
*/
static __inline__ int dn_congested(struct sock *sk)
{
return atomic_read(&sk->rmem_alloc) > (sk->rcvbuf >> 1);
}
#endif /* _NET_DN_NSP_H */
|
