1 /* $OpenBSD: get.c,v 1.8 2009/10/27 23:59:52 deraadt Exp $ */
2
3 /*
4 * Copyright (c) 1993-2006 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 #include <sys/types.h>
28 #include "common/mopdef.h"
29
30 u_char
mopGetChar(u_char * pkt,int * idx)31 mopGetChar(u_char *pkt, int *idx)
32 {
33 u_char ret;
34
35 ret = pkt[*idx];
36 *idx = *idx + 1;
37 return (ret);
38 }
39
40 u_short
mopGetShort(u_char * pkt,int * idx)41 mopGetShort(u_char *pkt, int *idx)
42 {
43 u_short ret;
44
45 ret = pkt[*idx] + pkt[*idx+1]*256;
46 *idx = *idx + 2;
47 return (ret);
48 }
49
50 u_short
mopGetNShort(u_char * pkt,int * idx)51 mopGetNShort(u_char *pkt, int *idx)
52 {
53 u_short ret;
54
55 ret = pkt[*idx]*256 + pkt[*idx+1];
56 *idx = *idx + 2;
57 return (ret);
58 }
59
60 u_long
mopGetLong(u_char * pkt,int * idx)61 mopGetLong(u_char *pkt, int *idx)
62 {
63 u_long ret;
64
65 ret = pkt[*idx] + pkt[*idx+1]*0x100 + pkt[*idx+2]*0x10000 +
66 pkt[*idx+3]*0x1000000;
67 *idx = *idx + 4;
68 return (ret);
69 }
70
71 void
mopGetMulti(u_char * pkt,int * idx,u_char * dest,int size)72 mopGetMulti(u_char *pkt, int *idx, u_char *dest, int size)
73 {
74 int i;
75
76 for (i = 0; i < size; i++)
77 dest[i] = pkt[*idx+i];
78 *idx = *idx + size;
79 }
80
81 int
mopGetTrans(u_char * pkt,int trans)82 mopGetTrans(u_char *pkt, int trans)
83 {
84 u_short ptype;
85
86 if (trans == 0) {
87 ptype = pkt[12]*256 + pkt[13];
88 if (ptype < 1600)
89 trans = TRANS_8023;
90 else
91 trans = TRANS_ETHER;
92 }
93 return (trans);
94 }
95
96 void
mopGetHeader(u_char * pkt,int * idx,u_char ** dst,u_char ** src,u_short * proto,int * len,int trans)97 mopGetHeader(u_char *pkt, int *idx, u_char **dst, u_char **src,
98 u_short *proto, int *len, int trans)
99 {
100 *dst = pkt;
101 *src = pkt + 6;
102 *idx = *idx + 12;
103
104 switch (trans) {
105 case TRANS_ETHER:
106 *proto = mopGetNShort(pkt, idx);
107 *len = (int)mopGetShort(pkt, idx);
108 break;
109 case TRANS_8023:
110 *len = (int)mopGetNShort(pkt, idx);
111 *idx = *idx + 6;
112 *proto = mopGetNShort(pkt, idx);
113 break;
114 }
115 }
116
117 u_short
mopGetLength(u_char * pkt,int trans)118 mopGetLength(u_char *pkt, int trans)
119 {
120 switch (trans) {
121 case TRANS_ETHER:
122 return (pkt[14] + pkt[15]*256);
123 case TRANS_8023:
124 return (pkt[12]*256 + pkt[13]);
125 }
126 return (0);
127 }
128