1 /*        $NetBSD: ddp.h,v 1.2 2005/12/10 23:29:05 elad Exp $          */
2 
3 /*
4  * Copyright (c) 1990,1991 Regents of The University of Michigan.
5  * All Rights Reserved.
6  *
7  * Permission to use, copy, modify, and distribute this software and
8  * its documentation for any purpose and without fee is hereby granted,
9  * provided that the above copyright notice appears in all copies and
10  * that both that copyright notice and this permission notice appear
11  * in supporting documentation, and that the name of The University
12  * of Michigan not be used in advertising or publicity pertaining to
13  * distribution of the software without specific, written prior
14  * permission. This software is supplied as is without expressed or
15  * implied warranties of any kind.
16  *
17  * This product includes software developed by the University of
18  * California, Berkeley and its contributors.
19  *
20  *        Research Systems Unix Group
21  *        The University of Michigan
22  *        c/o Wesley Craig
23  *        535 W. William Street
24  *        Ann Arbor, Michigan
25  *        +1-313-764-2278
26  *        netatalk@umich.edu
27  */
28 
29 #ifndef _NETATALK_DDP_H_
30 #define _NETATALK_DDP_H_
31 
32 #ifndef BYTE_ORDER
33   #error "Undefined Byte order"
34 #endif
35 
36 /*
37  * <-1byte(8bits) ->
38  * +---------------+
39  * | 0 | hopc  |len|
40  * +---------------+
41  * | len (cont)    |
42  * +---------------+
43  * |               |
44  * +- DDP csum    -+
45  * |               |
46  * +---------------+
47  * |               |
48  * +- Dest NET    -+
49  * |               |
50  * +---------------+
51  * |               |
52  * +- Src NET     -+
53  * |               |
54  * +---------------+
55  * | Dest NODE     |
56  * +---------------+
57  * | Src NODE      |
58  * +---------------+
59  * | Dest PORT     |
60  * +---------------+
61  * | Src PORT      |
62  * +---------------+
63  *
64  * On Apples, there is also a ddp_type field, after src_port. However,
65  * under this unix implementation, user level processes need to be able
66  * to set the ddp_type. In later revisions, the ddp_type may only be
67  * available in a raw_appletalk interface.
68  */
69 
70 struct elaphdr {
71           u_char          el_dnode;
72           u_char          el_snode;
73           u_char          el_type;
74 };
75 
76 #define   SZ_ELAPHDR          3
77 
78 #define ELAP_DDPSHORT         0x01
79 #define ELAP_DDPEXTEND        0x02
80 
81 /*
82  * Extended DDP header. Includes sickness for dealing with arbitrary
83  * bitfields on a little-endian arch.
84  */
85 struct ddpehdr {
86           union {
87                     struct {
88 #if BYTE_ORDER == BIG_ENDIAN
89                               unsigned        dub_pad:2;
90                               unsigned        dub_hops:4;
91                               unsigned        dub_len:10;
92                               unsigned        dub_sum:16;
93 #endif
94 #if BYTE_ORDER == LITTLE_ENDIAN
95                               unsigned        dub_sum:16;
96                               unsigned        dub_len:10;
97                               unsigned        dub_hops:4;
98                               unsigned        dub_pad:2;
99 #endif
100                     }                   du_bits;
101                     unsigned        du_bytes;
102           }               deh_u;
103 #define deh_pad               deh_u.du_bits.dub_pad
104 #define deh_hops    deh_u.du_bits.dub_hops
105 #define deh_len               deh_u.du_bits.dub_len
106 #define deh_sum               deh_u.du_bits.dub_sum
107 #define deh_bytes   deh_u.du_bytes
108           u_short         deh_dnet;
109           u_short         deh_snet;
110           u_char          deh_dnode;
111           u_char          deh_snode;
112           u_char          deh_dport;
113           u_char          deh_sport;
114 };
115 
116 #define DDP_MAXHOPS 15
117 
118 struct ddpshdr {
119           union {
120                     struct {
121 #if BYTE_ORDER == BIG_ENDIAN
122                               unsigned        dub_pad:6;
123                               unsigned        dub_len:10;
124                               unsigned        dub_dport:8;
125                               unsigned        dub_sport:8;
126 #endif
127 #if BYTE_ORDER == LITTLE_ENDIAN
128                               unsigned        dub_sport:8;
129                               unsigned        dub_dport:8;
130                               unsigned        dub_len:10;
131                               unsigned        dub_pad:6;
132 #endif
133                     }               du_bits;
134                     unsigned        du_bytes;
135           }               dsh_u;
136 #define dsh_pad               dsh_u.du_bits.dub_pad
137 #define dsh_len               dsh_u.du_bits.dub_len
138 #define dsh_dport   dsh_u.du_bits.dub_dport
139 #define dsh_sport   dsh_u.du_bits.dub_sport
140 #define dsh_bytes   dsh_u.du_bytes
141 };
142 
143 #endif /* !_NETATALK_DDP_H_ */
144