sys/netproto/atalk/ddp.h

   1 /*
   2  * Copyright (c) 1990,1991 Regents of The University of Michigan.
   3  * All Rights Reserved.
   4  *
   5  * Permission to use, copy, modify, and distribute this software and
   6  * its documentation for any purpose and without fee is hereby granted,
   7  * provided that the above copyright notice appears in all copies and
   8  * that both that copyright notice and this permission notice appear
   9  * in supporting documentation, and that the name of The University
  10  * of Michigan not be used in advertising or publicity pertaining to
  11  * distribution of the software without specific, written prior
  12  * permission. This software is supplied as is without expressed or
  13  * implied warranties of any kind.
  14  *
  15  *      Research Systems Unix Group
  16  *      The University of Michigan
  17  *      c/o Mike Clark
  18  *      535 W. William Street
  19  *      Ann Arbor, Michigan
  20  *      +1-313-763-0525
  21  *      netatalk@itd.umich.edu
  22  */
  23 #ifndef _NETATALK_DDP_H_
  24 #define _NETATALK_DDP_H_ 1
  25
  26 /*
  27  * <-1byte(8bits) ->
  28  * +---------------+
  29  * | 0 | hopc  |len|
  30  * +---------------+
  31  * | len (cont)    |
  32  * +---------------+
  33  * |               |
  34  * +- DDP csum    -+
  35  * |               |
  36  * +---------------+
  37  * |               |
  38  * +- Dest NET    -+
  39  * |               |
  40  * +---------------+
  41  * |               |
  42  * +- Src NET     -+
  43  * |               |
  44  * +---------------+
  45  * | Dest NODE     |
  46  * +---------------+
  47  * | Src NODE      |
  48  * +---------------+
  49  * | Dest PORT     |
  50  * +---------------+
  51  * | Src PORT      |
  52  * +---------------+
  53  *
  54  * On Apples, there is also a ddp_type field, after src_port. However,
  55  * under this unix implementation, user level processes need to be able
  56  * to set the ddp_type. In later revisions, the ddp_type may only be
  57  * available in a raw_appletalk interface.
  58  */
  59
  60 struct elaphdr {
  61     u_char      el_dnode;
  62     u_char      el_snode;
  63     u_char      el_type;
  64 };
  65
  66 #define SZ_ELAPHDR      3
  67
  68 #define ELAP_DDPSHORT   0x01
  69 #define ELAP_DDPEXTEND  0x02
  70
  71 /*
  72  * Extended DDP header. Includes sickness for dealing with arbitrary
  73  * bitfields on a little-endian arch.
  74  */
  75 struct ddpehdr {
  76     union {
  77         struct {
  78 #if BYTE_ORDER == BIG_ENDIAN
  79     unsigned            dub_pad:2;
  80     unsigned            dub_hops:4;
  81     unsigned            dub_len:10;
  82     unsigned            dub_sum:16;
  83 #endif
  84 #if BYTE_ORDER == LITTLE_ENDIAN
  85     unsigned            dub_sum:16;
  86     unsigned            dub_len:10;
  87     unsigned            dub_hops:4;
  88     unsigned            dub_pad:2;
  89 #endif
  90         } du_bits;
  91         unsigned        du_bytes;
  92     } deh_u;
  93 #define deh_pad         deh_u.du_bits.dub_pad
  94 #define deh_hops        deh_u.du_bits.dub_hops
  95 #define deh_len         deh_u.du_bits.dub_len
  96 #define deh_sum         deh_u.du_bits.dub_sum
  97 #define deh_bytes       deh_u.du_bytes
  98     u_short             deh_dnet;
  99     u_short             deh_snet;
 100     u_char              deh_dnode;
 101     u_char              deh_snode;
 102     u_char              deh_dport;
 103     u_char              deh_sport;
 104 };
 105
 106 #define DDP_MAXHOPS     15
 107
 108 struct ddpshdr {
 109     union {
 110         struct {
 111 #if BYTE_ORDER == BIG_ENDIAN
 112     unsigned            dub_pad:6;
 113     unsigned            dub_len:10;
 114     unsigned            dub_dport:8;
 115     unsigned            dub_sport:8;
 116 #endif
 117 #if BYTE_ORDER == LITTLE_ENDIAN
 118     unsigned            dub_sport:8;
 119     unsigned            dub_dport:8;
 120     unsigned            dub_len:10;
 121     unsigned            dub_pad:6;
 122 #endif
 123         } du_bits;
 124         unsigned        du_bytes;
 125     } dsh_u;
 126 #define dsh_pad         dsh_u.du_bits.dub_pad
 127 #define dsh_len         dsh_u.du_bits.dub_len
 128 #define dsh_dport       dsh_u.du_bits.dub_dport
 129 #define dsh_sport       dsh_u.du_bits.dub_sport
 130 #define dsh_bytes       dsh_u.du_bytes
 131 };
 132
 133 #endif /* _NETATALK_DDP_H_ */