1 /* $NetBSD: get.c,v 1.6 2009/11/17 18:58:07 drochner 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 #include <sys/cdefs.h> 28 #ifndef lint 29 __RCSID("$NetBSD: get.c,v 1.6 2009/11/17 18:58:07 drochner Exp $"); 30 #endif 31 32 #include "os.h" 33 #include "get.h" 34 #include "mopdef.h" 35 36 u_char 37 mopGetChar(const u_char *pkt, int *idx) 38 { 39 u_char ret; 40 41 ret = pkt[*idx]; 42 *idx = *idx + 1; 43 return(ret); 44 } 45 46 u_short 47 mopGetShort(const u_char *pkt, int *idx) 48 { 49 u_short ret; 50 51 ret = pkt[*idx] + pkt[*idx+1]*256; 52 *idx = *idx + 2; 53 return(ret); 54 } 55 56 u_int32_t 57 mopGetLong(const u_char *pkt, int *idx) 58 { 59 u_int32_t ret; 60 61 ret = pkt[*idx] + 62 pkt[*idx+1]*0x100 + 63 pkt[*idx+2]*0x10000 + 64 pkt[*idx+3]*0x1000000; 65 *idx = *idx + 4; 66 return(ret); 67 } 68 69 void 70 mopGetMulti(const u_char *pkt, int *idx, u_char *dest, int size) 71 { 72 int i; 73 74 for (i = 0; i < size; i++) { 75 dest[i] = pkt[*idx+i]; 76 } 77 *idx = *idx + size; 78 79 } 80 81 int 82 mopGetTrans(const u_char *pkt, int trans) 83 { 84 const u_short *ptype; 85 86 if (trans == 0) { 87 ptype = (const u_short *)(pkt+12); 88 if (ntohs(*ptype) < 1600) { 89 trans = TRANS_8023; 90 } else { 91 trans = TRANS_ETHER; 92 } 93 } 94 return(trans); 95 } 96 97 void 98 mopGetHeader(const u_char *pkt, int *idx, const u_char **dst, const u_char **src, 99 u_short *proto, int *len, int trans) 100 { 101 *dst = pkt; 102 *src = pkt + 6; 103 *idx = *idx + 12; 104 105 switch(trans) { 106 case TRANS_ETHER: 107 *proto = (u_short)(pkt[*idx]*256 + pkt[*idx+1]); 108 *idx = *idx + 2; 109 *len = (int)(pkt[*idx+1]*256 + pkt[*idx]); 110 *idx = *idx + 2; 111 break; 112 case TRANS_8023: 113 *len = (int)(pkt[*idx]*256 + pkt[*idx+1]); 114 *idx = *idx + 8; 115 *proto = (u_short)(pkt[*idx]*256 + pkt[*idx+1]); 116 *idx = *idx + 2; 117 break; 118 } 119 } 120 121 u_short 122 mopGetLength(const u_char *pkt, int trans) 123 { 124 switch(trans) { 125 case TRANS_ETHER: 126 return(pkt[15]*256 + pkt[14]); 127 break; 128 case TRANS_8023: 129 return(pkt[12]*256 + pkt[13]); 130 break; 131 } 132 return(0); 133 } 134