epan/crc16-tvb.c

   1 /* crc16-tvb.c
   2  * CRC-16 tvb routines
   3  *
   4  * 2004 Richard van der Hoff <richardv@mxtelecom.com>
   5  *
   6  * Wireshark - Network traffic analyzer
   7  * By Gerald Combs <gerald@wireshark.org>
   8  * Copyright 1998 Gerald Combs
   9  *
  10  * SPDX-License-Identifier: GPL-2.0-or-later
  11  *
  12  * References:
  13  *  "A Painless Guide to CRC Error Detection Algorithms", Ross Williams
  14  *      http://www.repairfaq.org/filipg/LINK/F_crc_v3.html
  15  *
  16  *  ITU-T Recommendation V.42 (2002), "Error-Correcting Procedures for
  17  *      DCEs using asynchronous-to-synchronous conversion", Para. 8.1.1.6.1
  18  */
  19
  20 #include "config.h"
  21
  22 #include <glib.h>
  23 #include <epan/tvbuff.h>
  24 #include <wsutil/crc16.h>
  25 #include <epan/crc16-tvb.h>
  26 #include <wsutil/crc16-plain.h>
  27
  28
  29 uint16_t crc16_ccitt_tvb(tvbuff_t *tvb, unsigned len)
  30 {
  31     const uint8_t *buf;
  32
  33     tvb_ensure_bytes_exist(tvb, 0, len);  /* len == -1 not allowed */
  34     buf = tvb_get_ptr(tvb, 0, len);
  35
  36     return crc16_ccitt(buf, len);
  37 }
  38
  39 uint16_t crc16_x25_ccitt_tvb(tvbuff_t *tvb, unsigned len)
  40 {
  41     const uint8_t *buf;
  42
  43     tvb_ensure_bytes_exist(tvb, 0, len);  /* len == -1 not allowed */
  44     buf = tvb_get_ptr(tvb, 0, len);
  45
  46     return crc16_x25_ccitt_seed(buf, len, 0xFFFF);
  47 }
  48
  49 uint16_t crc16_r3_ccitt_tvb(tvbuff_t *tvb, int offset, unsigned len)
  50 {
  51     const uint8_t *buf;
  52
  53     tvb_ensure_bytes_exist(tvb, offset, len);  /* len == -1 not allowed */
  54     buf = tvb_get_ptr(tvb, offset, len);
  55
  56     return crc16_x25_ccitt_seed(buf, len, 0);
  57 }
  58
  59 uint16_t crc16_ccitt_tvb_offset(tvbuff_t *tvb, unsigned offset, unsigned len)
  60 {
  61     const uint8_t *buf;
  62
  63     tvb_ensure_bytes_exist(tvb, offset, len);  /* len == -1 not allowed */
  64     buf = tvb_get_ptr(tvb, offset, len);
  65
  66     return crc16_ccitt(buf, len);
  67 }
  68
  69 uint16_t crc16_ccitt_tvb_seed(tvbuff_t *tvb, unsigned len, uint16_t seed)
  70 {
  71     const uint8_t *buf;
  72
  73     tvb_ensure_bytes_exist(tvb, 0, len);  /* len == -1 not allowed */
  74     buf = tvb_get_ptr(tvb, 0, len);
  75
  76     return crc16_ccitt_seed(buf, len, seed);
  77 }
  78
  79 uint16_t crc16_ccitt_tvb_offset_seed(tvbuff_t *tvb, unsigned offset, unsigned len, uint16_t seed)
  80 {
  81     const uint8_t *buf;
  82
  83     tvb_ensure_bytes_exist(tvb, offset, len);  /* len == -1 not allowed */
  84     buf = tvb_get_ptr(tvb, offset, len);
  85
  86     return crc16_ccitt_seed(buf, len, seed);
  87 }
  88
  89 uint16_t crc16_iso14443a_tvb_offset(tvbuff_t *tvb, unsigned offset, unsigned len)
  90 {
  91     const uint8_t *buf;
  92
  93     tvb_ensure_bytes_exist(tvb, offset, len);  /* len == -1 not allowed */
  94     buf = tvb_get_ptr(tvb, offset, len);
  95
  96     return crc16_iso14443a(buf, len);
  97 }
  98
  99 uint16_t crc16_usb_tvb_offset(tvbuff_t *tvb, unsigned offset, unsigned len)
 100 {
 101     const uint8_t *buf;
 102
 103     tvb_ensure_bytes_exist(tvb, offset, len);  /* len == -1 not allowed */
 104     buf = tvb_get_ptr(tvb, offset, len);
 105
 106     return crc16_usb(buf, len);
 107 }
 108
 109 uint16_t crc16_plain_tvb_offset(tvbuff_t *tvb, unsigned offset, unsigned len)
 110 {
 111     uint16_t crc = crc16_plain_init();
 112     const uint8_t *buf;
 113
 114     tvb_ensure_bytes_exist(tvb, offset, len);  /* len == -1 not allowed */
 115     buf = tvb_get_ptr(tvb, offset, len);
 116
 117     crc = crc16_plain_update(crc, buf, len);
 118
 119     return crc16_plain_finalize(crc);
 120 }
 121
 122 uint16_t crc16_plain_tvb_offset_seed(tvbuff_t *tvb, unsigned offset, unsigned len, uint16_t crc)
 123 {
 124     const uint8_t *buf;
 125
 126     tvb_ensure_bytes_exist(tvb, offset, len);  /* len == -1 not allowed */
 127     buf = tvb_get_ptr(tvb, offset, len);
 128
 129     crc = crc16_plain_update(crc, buf, len);
 130
 131     return crc16_plain_finalize(crc);
 132 }
 133
 134 uint16_t crc16_0x9949_tvb_offset_seed(tvbuff_t *tvb, unsigned offset, unsigned len, uint16_t seed)
 135 {
 136     const uint8_t *buf;
 137
 138     tvb_ensure_bytes_exist(tvb, offset, len);  /* len == -1 not allowed */
 139     buf = tvb_get_ptr(tvb, offset, len);
 140
 141     return crc16_0x9949_seed(buf, len, seed);
 142 }
 143
 144 uint16_t crc16_0x3D65_tvb_offset_seed(tvbuff_t *tvb, unsigned offset, unsigned len, uint16_t seed)
 145 {
 146     const uint8_t *buf;
 147
 148     tvb_ensure_bytes_exist(tvb, offset, len);  /* len == -1 not allowed */
 149     buf = tvb_get_ptr(tvb, offset, len);
 150
 151     return crc16_0x3D65_seed(buf, len, seed);
 152 }
 153
 154 /*
 155  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 156  *
 157  * Local variables:
 158  * c-basic-offset: 4
 159  * tab-width: 8
 160  * indent-tabs-mode: nil
 161  * End:
 162  *
 163  * vi: set shiftwidth=4 tabstop=8 expandtab:
 164  * :indentSize=4:tabSize=8:noTabs=true:
 165  */