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 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 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 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 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 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 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 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