The Tcpdump Group git mirrors - tcpdump/blob - print-ascii.c

   1 /*      $NetBSD: print-ascii.c,v 1.1 1999/09/30 14:49:12 sjg Exp $      */
   2
   3 /*-
   4  * Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
   5  * All rights reserved.
   6  *
   7  * This code is derived from software contributed to The NetBSD Foundation
   8  * by Alan Barrett and Simon J. Gerraty.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *        This product includes software developed by the NetBSD
  21  *        Foundation, Inc. and its contributors.
  22  * 4. Neither the name of The NetBSD Foundation nor the names of its
  23  *    contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  36  * POSSIBILITY OF SUCH DAMAGE.
  37  */
  38
  39 /* \summary: ASCII packet dump printer */
  40
  41 #ifdef HAVE_CONFIG_H
  42 #include <config.h>
  43 #endif
  44
  45 #include "netdissect-stdinc.h"
  46 #include <stdio.h>
  47
  48 #include "netdissect.h"
  49 #include "extract.h"
  50
  51 #define ASCII_LINELENGTH 300
  52 #define HEXDUMP_BYTES_PER_LINE 16
  53 #define HEXDUMP_SHORTS_PER_LINE (HEXDUMP_BYTES_PER_LINE / 2)
  54 #define HEXDUMP_HEXSTUFF_PER_SHORT 5 /* 4 hex digits and a space */
  55 #define HEXDUMP_HEXSTUFF_PER_LINE \
  56                 (HEXDUMP_HEXSTUFF_PER_SHORT * HEXDUMP_SHORTS_PER_LINE)
  57
  58 static void hex_and_ascii_print_with_offset(netdissect_options *, const char *, const u_char *, u_int, u_int);
  59
  60 void
  61 ascii_print(netdissect_options *ndo,
  62             const u_char *cp, u_int length)
  63 {
  64         u_int caplength;
  65         u_char s;
  66
  67         ndo->ndo_protocol = "ascii";
  68         caplength = (ndo->ndo_snapend > cp) ? ND_BYTES_AVAILABLE_AFTER(cp) : 0;
  69         if (length > caplength)
  70                 length = caplength;
  71         ND_PRINT("\n");
  72         while (length > 0) {
  73                 s = GET_U_1(cp);
  74                 cp++;
  75                 length--;
  76                 if (s == '\r') {
  77                         /*
  78                          * Don't print CRs at the end of the line; they
  79                          * don't belong at the ends of lines on UN*X,
  80                          * and the standard I/O library will give us one
  81                          * on Windows so we don't need to print one
  82                          * ourselves.
  83                          *
  84                          * In the middle of a line, just print a '.'.
  85                          */
  86                         if (length > 1 && GET_U_1(cp) != '\n')
  87                                 ND_PRINT(".");
  88                 } else {
  89                         if (!ND_ISGRAPH(s) &&
  90                             (s != '\t' && s != ' ' && s != '\n'))
  91                                 ND_PRINT(".");
  92                         else
  93                                 ND_PRINT("%c", s);
  94                 }
  95         }
  96 }
  97
  98 static void
  99 hex_and_ascii_print_with_offset(netdissect_options *ndo, const char *ident,
 100     const u_char *cp, u_int length, u_int oset)
 101 {
 102         u_int caplength;
 103         u_int i;
 104         u_int s1, s2;
 105         u_int nshorts;
 106         char hexstuff[HEXDUMP_SHORTS_PER_LINE*HEXDUMP_HEXSTUFF_PER_SHORT+1], *hsp;
 107         char asciistuff[ASCII_LINELENGTH+1], *asp;
 108
 109         caplength = (ndo->ndo_snapend > cp) ? ND_BYTES_AVAILABLE_AFTER(cp) : 0;
 110         if (length > caplength)
 111                 length = caplength;
 112         nshorts = length / sizeof(u_short);
 113         i = 0;
 114         hsp = hexstuff; asp = asciistuff;
 115         while (nshorts != 0) {
 116                 s1 = GET_U_1(cp);
 117                 cp++;
 118                 s2 = GET_U_1(cp);
 119                 cp++;
 120                 (void)snprintf(hsp, sizeof(hexstuff) - (hsp - hexstuff),
 121                     " %02x%02x", s1, s2);
 122                 hsp += HEXDUMP_HEXSTUFF_PER_SHORT;
 123                 *(asp++) = (char)(ND_ISGRAPH(s1) ? s1 : '.');
 124                 *(asp++) = (char)(ND_ISGRAPH(s2) ? s2 : '.');
 125                 i++;
 126                 if (i >= HEXDUMP_SHORTS_PER_LINE) {
 127                         *hsp = *asp = '\0';
 128                         ND_PRINT("%s0x%04x: %-*s  %s",
 129                             ident, oset, HEXDUMP_HEXSTUFF_PER_LINE,
 130                             hexstuff, asciistuff);
 131                         i = 0; hsp = hexstuff; asp = asciistuff;
 132                         oset += HEXDUMP_BYTES_PER_LINE;
 133                 }
 134                 nshorts--;
 135         }
 136         if (length & 1) {
 137                 s1 = GET_U_1(cp);
 138                 cp++;
 139                 (void)snprintf(hsp, sizeof(hexstuff) - (hsp - hexstuff),
 140                     " %02x", s1);
 141                 hsp += 3;
 142                 *(asp++) = (char)(ND_ISGRAPH(s1) ? s1 : '.');
 143                 ++i;
 144         }
 145         if (i > 0) {
 146                 *hsp = *asp = '\0';
 147                 ND_PRINT("%s0x%04x: %-*s  %s",
 148                      ident, oset, HEXDUMP_HEXSTUFF_PER_LINE,
 149                      hexstuff, asciistuff);
 150         }
 151 }
 152
 153 void
 154 hex_and_ascii_print(netdissect_options *ndo, const char *ident,
 155     const u_char *cp, u_int length)
 156 {
 157         hex_and_ascii_print_with_offset(ndo, ident, cp, length, 0);
 158 }
 159
 160 /*
 161  * telnet_print() wants this.  It is essentially default_print_unaligned()
 162  */
 163 void
 164 hex_print_with_offset(netdissect_options *ndo,
 165                       const char *ident, const u_char *cp, u_int length,
 166                       u_int oset)
 167 {
 168         u_int caplength;
 169         u_int i, s;
 170         u_int nshorts;
 171
 172         caplength = (ndo->ndo_snapend > cp) ? ND_BYTES_AVAILABLE_AFTER(cp) : 0;
 173         if (length > caplength)
 174                 length = caplength;
 175         nshorts = length / sizeof(u_short);
 176         i = 0;
 177         while (nshorts != 0) {
 178                 if ((i++ % 8) == 0) {
 179                         ND_PRINT("%s0x%04x: ", ident, oset);
 180                         oset += HEXDUMP_BYTES_PER_LINE;
 181                 }
 182                 s = GET_U_1(cp);
 183                 cp++;
 184                 ND_PRINT(" %02x%02x", s, GET_U_1(cp));
 185                 cp++;
 186                 nshorts--;
 187         }
 188         if (length & 1) {
 189                 if ((i % 8) == 0)
 190                         ND_PRINT("%s0x%04x: ", ident, oset);
 191                 ND_PRINT(" %02x", GET_U_1(cp));
 192         }
 193 }
 194
 195 /*
 196  * just for completeness
 197  */
 198 void
 199 hex_print(netdissect_options *ndo,const char *ident, const u_char *cp, u_int length)
 200 {
 201   hex_print_with_offset(ndo, ident, cp, length, 0);
 202 }
 203
 204 #ifdef MAIN
 205 int
 206 main(int argc, char *argv[])
 207 {
 208         hex_print("\n\t", "Hello, World!\n", 14);
 209         printf("\n");
 210         hex_and_ascii_print("\n\t", "Hello, World!\n", 14);
 211         printf("\n");
 212         ascii_print("Hello, World!\n", 14);
 213         printf("\n");
 214 #define TMSG "Now is the winter of our discontent...\n"
 215         hex_print_with_offset("\n\t", TMSG, sizeof(TMSG) - 1, 0x100);
 216         printf("\n");
 217         hex_and_ascii_print_with_offset("\n\t", TMSG, sizeof(TMSG) - 1, 0x100);
 218         printf("\n");
 219         exit(0);
 220 }
 221 #endif /* MAIN */