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
  47 #include <stdio.h>
  48
  49 #include "netdissect-ctype.h"
  50
  51 #include "netdissect.h"
  52 #include "extract.h"
  53
  54 #define ASCII_LINELENGTH 300
  55 #define HEXDUMP_BYTES_PER_LINE 16
  56 #define HEXDUMP_SHORTS_PER_LINE (HEXDUMP_BYTES_PER_LINE / 2)
  57 #define HEXDUMP_HEXSTUFF_PER_SHORT 5 /* 4 hex digits and a space */
  58 #define HEXDUMP_HEXSTUFF_PER_LINE \
  59                 (HEXDUMP_HEXSTUFF_PER_SHORT * HEXDUMP_SHORTS_PER_LINE)
  60
  61 void
  62 ascii_print(netdissect_options *ndo,
  63             const u_char *cp, u_int length)
  64 {
  65         u_int caplength;
  66         u_char s;
  67
  68         ndo->ndo_protocol = "ascii";
  69         caplength = (ndo->ndo_snapend > cp) ? ND_BYTES_AVAILABLE_AFTER(cp) : 0;
  70         if (length > caplength)
  71                 length = caplength;
  72         ND_PRINT("\n");
  73         while (length > 0) {
  74                 s = GET_U_1(cp);
  75                 cp++;
  76                 length--;
  77                 if (s == '\r') {
  78                         /*
  79                          * Don't print CRs at the end of the line; they
  80                          * don't belong at the ends of lines on UN*X,
  81                          * and the standard I/O library will give us one
  82                          * on Windows so we don't need to print one
  83                          * ourselves.
  84                          *
  85                          * In the middle of a line, just print a '.'.
  86                          */
  87                         if (length > 1 && GET_U_1(cp) != '\n')
  88                                 ND_PRINT(".");
  89                 } else {
  90                         if (!ND_ASCII_ISGRAPH(s) &&
  91                             (s != '\t' && s != ' ' && s != '\n'))
  92                                 ND_PRINT(".");
  93                         else
  94                                 ND_PRINT("%c", s);
  95                 }
  96         }
  97 }
  98
  99 static void
 100 hex_and_ascii_print_with_offset(netdissect_options *ndo, const char *ident,
 101     const u_char *cp, u_int length, u_int oset)
 102 {
 103         u_int caplength;
 104         u_int i;
 105         u_int s1, s2;
 106         u_int nshorts;
 107         char hexstuff[HEXDUMP_SHORTS_PER_LINE*HEXDUMP_HEXSTUFF_PER_SHORT+1], *hsp;
 108         char asciistuff[ASCII_LINELENGTH+1], *asp;
 109
 110         caplength = (ndo->ndo_snapend > cp) ? ND_BYTES_AVAILABLE_AFTER(cp) : 0;
 111         if (length > caplength)
 112                 length = caplength;
 113         nshorts = length / sizeof(u_short);
 114         i = 0;
 115         hsp = hexstuff; asp = asciistuff;
 116         while (nshorts != 0) {
 117                 s1 = GET_U_1(cp);
 118                 cp++;
 119                 s2 = GET_U_1(cp);
 120                 cp++;
 121                 (void)snprintf(hsp, sizeof(hexstuff) - (hsp - hexstuff),
 122                     " %02x%02x", s1, s2);
 123                 hsp += HEXDUMP_HEXSTUFF_PER_SHORT;
 124                 *(asp++) = (char)(ND_ASCII_ISGRAPH(s1) ? s1 : '.');
 125                 *(asp++) = (char)(ND_ASCII_ISGRAPH(s2) ? s2 : '.');
 126                 i++;
 127                 if (i >= HEXDUMP_SHORTS_PER_LINE) {
 128                         *hsp = *asp = '\0';
 129                         ND_PRINT("%s0x%04x: %-*s  %s",
 130                             ident, oset, HEXDUMP_HEXSTUFF_PER_LINE,
 131                             hexstuff, asciistuff);
 132                         i = 0; hsp = hexstuff; asp = asciistuff;
 133                         oset += HEXDUMP_BYTES_PER_LINE;
 134                 }
 135                 nshorts--;
 136         }
 137         if (length & 1) {
 138                 s1 = GET_U_1(cp);
 139                 cp++;
 140                 (void)snprintf(hsp, sizeof(hexstuff) - (hsp - hexstuff),
 141                     " %02x", s1);
 142                 hsp += 3;
 143                 *(asp++) = (char)(ND_ASCII_ISGRAPH(s1) ? s1 : '.');
 144                 ++i;
 145         }
 146         if (i > 0) {
 147                 *hsp = *asp = '\0';
 148                 ND_PRINT("%s0x%04x: %-*s  %s",
 149                      ident, oset, HEXDUMP_HEXSTUFF_PER_LINE,
 150                      hexstuff, asciistuff);
 151         }
 152 }
 153
 154 void
 155 hex_and_ascii_print(netdissect_options *ndo, const char *ident,
 156     const u_char *cp, u_int length)
 157 {
 158         hex_and_ascii_print_with_offset(ndo, ident, cp, length, 0);
 159 }
 160
 161 /*
 162  * telnet_print() wants this.  It is essentially default_print_unaligned()
 163  */
 164 void
 165 hex_print_with_offset(netdissect_options *ndo,
 166                       const char *ident, const u_char *cp, u_int length,
 167                       u_int oset)
 168 {
 169         u_int caplength;
 170         u_int i, s;
 171         u_int nshorts;
 172
 173         caplength = (ndo->ndo_snapend > cp) ? ND_BYTES_AVAILABLE_AFTER(cp) : 0;
 174         if (length > caplength)
 175                 length = caplength;
 176         nshorts = length / sizeof(u_short);
 177         i = 0;
 178         while (nshorts != 0) {
 179                 if ((i++ % 8) == 0) {
 180                         ND_PRINT("%s0x%04x: ", ident, oset);
 181                         oset += HEXDUMP_BYTES_PER_LINE;
 182                 }
 183                 s = GET_U_1(cp);
 184                 cp++;
 185                 ND_PRINT(" %02x%02x", s, GET_U_1(cp));
 186                 cp++;
 187                 nshorts--;
 188         }
 189         if (length & 1) {
 190                 if ((i % 8) == 0)
 191                         ND_PRINT("%s0x%04x: ", ident, oset);
 192                 ND_PRINT(" %02x", GET_U_1(cp));
 193         }
 194 }
 195
 196 /*
 197  * just for completeness
 198  */
 199 void
 200 hex_print(netdissect_options *ndo,const char *ident, const u_char *cp, u_int length)
 201 {
 202   hex_print_with_offset(ndo, ident, cp, length, 0);
 203 }
 204
 205 #ifdef MAIN
 206 int
 207 main(int argc, char *argv[])
 208 {
 209         hex_print("\n\t", "Hello, World!\n", 14);
 210         printf("\n");
 211         hex_and_ascii_print("\n\t", "Hello, World!\n", 14);
 212         printf("\n");
 213         ascii_print("Hello, World!\n", 14);
 214         printf("\n");
 215 #define TMSG "Now is the winter of our discontent...\n"
 216         hex_print_with_offset("\n\t", TMSG, sizeof(TMSG) - 1, 0x100);
 217         printf("\n");
 218         hex_and_ascii_print_with_offset("\n\t", TMSG, sizeof(TMSG) - 1, 0x100);
 219         printf("\n");
 220         exit(0);
 221 }
 222 #endif /* MAIN */