1 /* $NetBSD: get.c,v 1.8 2024/12/03 05:57:02 kalvisd Exp $ */
2
3 /*
4 * Copyright (c) 1993-95 Mats O Jansson. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #if defined (HAVE_NBTOOL_CONFIG_H)
28 # include "nbtool_config.h"
29 #else
30 # include "port.h"
31 #endif /* defined (HAVE_NBTOOL_CONFIG_H) */
32 #ifndef lint
33 __RCSID("$NetBSD: get.c,v 1.8 2024/12/03 05:57:02 kalvisd Exp $");
34 #endif
35
36 #include "os.h"
37 #include "get.h"
38 #include "mopdef.h"
39
40 u_char
mopGetChar(const u_char * pkt,int * idx)41 mopGetChar(const u_char *pkt, int *idx)
42 {
43 u_char ret;
44
45 ret = pkt[*idx];
46 *idx = *idx + 1;
47 return(ret);
48 }
49
50 u_short
mopGetShort(const u_char * pkt,int * idx)51 mopGetShort(const u_char *pkt, int *idx)
52 {
53 u_short ret;
54
55 ret = pkt[*idx] + pkt[*idx+1]*256;
56 *idx = *idx + 2;
57 return(ret);
58 }
59
60 u_int32_t
mopGetLong(const u_char * pkt,int * idx)61 mopGetLong(const u_char *pkt, int *idx)
62 {
63 u_int32_t ret;
64
65 ret = pkt[*idx] +
66 pkt[*idx+1]*0x100 +
67 pkt[*idx+2]*0x10000 +
68 pkt[*idx+3]*0x1000000;
69 *idx = *idx + 4;
70 return(ret);
71 }
72
73 void
mopGetMulti(const u_char * pkt,int * idx,u_char * dest,int size)74 mopGetMulti(const u_char *pkt, int *idx, u_char *dest, int size)
75 {
76 int i;
77
78 for (i = 0; i < size; i++) {
79 dest[i] = pkt[*idx+i];
80 }
81 *idx = *idx + size;
82
83 }
84
85 int
mopGetTrans(const u_char * pkt,int trans)86 mopGetTrans(const u_char *pkt, int trans)
87 {
88 const u_short *ptype;
89
90 if (trans == 0) {
91 ptype = (const u_short *)(pkt+12);
92 if (ntohs(*ptype) < 1600) {
93 trans = TRANS_8023;
94 } else {
95 trans = TRANS_ETHER;
96 }
97 }
98 return(trans);
99 }
100
101 void
mopGetHeader(const u_char * pkt,int * idx,const u_char ** dst,const u_char ** src,u_short * proto,int * len,int trans)102 mopGetHeader(const u_char *pkt, int *idx, const u_char **dst, const u_char **src,
103 u_short *proto, int *len, int trans)
104 {
105 *dst = pkt;
106 *src = pkt + 6;
107 *idx = *idx + 12;
108
109 switch(trans) {
110 case TRANS_ETHER:
111 *proto = (u_short)(pkt[*idx]*256 + pkt[*idx+1]);
112 *idx = *idx + 2;
113 *len = (int)(pkt[*idx+1]*256 + pkt[*idx]);
114 *idx = *idx + 2;
115 break;
116 case TRANS_8023:
117 *len = (int)(pkt[*idx]*256 + pkt[*idx+1]);
118 *idx = *idx + 8;
119 *proto = (u_short)(pkt[*idx]*256 + pkt[*idx+1]);
120 *idx = *idx + 2;
121 break;
122 }
123 }
124
125 u_short
mopGetLength(const u_char * pkt,int trans)126 mopGetLength(const u_char *pkt, int trans)
127 {
128 switch(trans) {
129 case TRANS_ETHER:
130 return(pkt[15]*256 + pkt[14]);
131 break;
132 case TRANS_8023:
133 return(pkt[12]*256 + pkt[13]);
134 break;
135 }
136 return(0);
137 }
138