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 static void hex_and_ascii_print_with_offset(netdissect_options *, const char *, const u_char *, u_int, u_int);
  62
  63 void
  64 ascii_print(netdissect_options *ndo,
  65             const u_char *cp, u_int length)
  66 {
  67         u_int caplength;
  68         u_char s;
  69
  70         ndo->ndo_protocol = "ascii";
  71         caplength = (ndo->ndo_snapend > cp) ? ND_BYTES_AVAILABLE_AFTER(cp) : 0;
  72         if (length > caplength)
  73                 length = caplength;
  74         ND_PRINT("\n");
  75         while (length > 0) {
  76                 s = GET_U_1(cp);
  77                 cp++;
  78                 length--;
  79                 if (s == '\r') {
  80                         /*
  81                          * Don't print CRs at the end of the line; they
  82                          * don't belong at the ends of lines on UN*X,
  83                          * and the standard I/O library will give us one
  84                          * on Windows so we don't need to print one
  85                          * ourselves.
  86                          *
  87                          * In the middle of a line, just print a '.'.
  88                          */
  89                         if (length > 1 && GET_U_1(cp) != '\n')
  90                                 ND_PRINT(".");
  91                 } else {
  92                         if (!ND_ASCII_ISGRAPH(s) &&
  93                             (s != '\t' && s != ' ' && s != '\n'))
  94                                 ND_PRINT(".");
  95                         else
  96                                 ND_PRINT("%c", s);
  97                 }
  98         }
  99 }
 100
 101 static void
 102 hex_and_ascii_print_with_offset(netdissect_options *ndo, const char *ident,
 103     const u_char *cp, u_int length, u_int oset)
 104 {
 105         u_int caplength;
 106         u_int i;
 107         u_int s1, s2;
 108         u_int nshorts;
 109         char hexstuff[HEXDUMP_SHORTS_PER_LINE*HEXDUMP_HEXSTUFF_PER_SHORT+1], *hsp;
 110         char asciistuff[ASCII_LINELENGTH+1], *asp;
 111
 112         caplength = (ndo->ndo_snapend > cp) ? ND_BYTES_AVAILABLE_AFTER(cp) : 0;
 113         if (length > caplength)
 114                 length = caplength;
 115         nshorts = length / sizeof(u_short);
 116         i = 0;
 117         hsp = hexstuff; asp = asciistuff;
 118         while (nshorts != 0) {
 119                 s1 = GET_U_1(cp);
 120                 cp++;
 121                 s2 = GET_U_1(cp);
 122                 cp++;
 123                 (void)snprintf(hsp, sizeof(hexstuff) - (hsp - hexstuff),
 124                     " %02x%02x", s1, s2);
 125                 hsp += HEXDUMP_HEXSTUFF_PER_SHORT;
 126                 *(asp++) = (char)(ND_ASCII_ISGRAPH(s1) ? s1 : '.');
 127                 *(asp++) = (char)(ND_ASCII_ISGRAPH(s2) ? s2 : '.');
 128                 i++;
 129                 if (i >= HEXDUMP_SHORTS_PER_LINE) {
 130                         *hsp = *asp = '\0';
 131                         ND_PRINT("%s0x%04x: %-*s  %s",
 132                             ident, oset, HEXDUMP_HEXSTUFF_PER_LINE,
 133                             hexstuff, asciistuff);
 134                         i = 0; hsp = hexstuff; asp = asciistuff;
 135                         oset += HEXDUMP_BYTES_PER_LINE;
 136                 }
 137                 nshorts--;
 138         }
 139         if (length & 1) {
 140                 s1 = GET_U_1(cp);
 141                 cp++;
 142                 (void)snprintf(hsp, sizeof(hexstuff) - (hsp - hexstuff),
 143                     " %02x", s1);
 144                 hsp += 3;
 145                 *(asp++) = (char)(ND_ASCII_ISGRAPH(s1) ? s1 : '.');
 146                 ++i;
 147         }
 148         if (i > 0) {
 149                 *hsp = *asp = '\0';
 150                 ND_PRINT("%s0x%04x: %-*s  %s",
 151                      ident, oset, HEXDUMP_HEXSTUFF_PER_LINE,
 152                      hexstuff, asciistuff);
 153         }
 154 }
 155
 156 void
 157 hex_and_ascii_print(netdissect_options *ndo, const char *ident,
 158     const u_char *cp, u_int length)
 159 {
 160         hex_and_ascii_print_with_offset(ndo, ident, cp, length, 0);
 161 }
 162
 163 /*
 164  * telnet_print() wants this.  It is essentially default_print_unaligned()
 165  */
 166 void
 167 hex_print_with_offset(netdissect_options *ndo,
 168                       const char *ident, const u_char *cp, u_int length,
 169                       u_int oset)
 170 {
 171         u_int caplength;
 172         u_int i, s;
 173         u_int nshorts;
 174
 175         caplength = (ndo->ndo_snapend > cp) ? ND_BYTES_AVAILABLE_AFTER(cp) : 0;
 176         if (length > caplength)
 177                 length = caplength;
 178         nshorts = length / sizeof(u_short);
 179         i = 0;
 180         while (nshorts != 0) {
 181                 if ((i++ % 8) == 0) {
 182                         ND_PRINT("%s0x%04x: ", ident, oset);
 183                         oset += HEXDUMP_BYTES_PER_LINE;
 184                 }
 185                 s = GET_U_1(cp);
 186                 cp++;
 187                 ND_PRINT(" %02x%02x", s, GET_U_1(cp));
 188                 cp++;
 189                 nshorts--;
 190         }
 191         if (length & 1) {
 192                 if ((i % 8) == 0)
 193                         ND_PRINT("%s0x%04x: ", ident, oset);
 194                 ND_PRINT(" %02x", GET_U_1(cp));
 195         }
 196 }
 197
 198 /*
 199  * just for completeness
 200  */
 201 void
 202 hex_print(netdissect_options *ndo,const char *ident, const u_char *cp, u_int length)
 203 {
 204   hex_print_with_offset(ndo, ident, cp, length, 0);
 205 }
 206
 207 #ifdef MAIN
 208 int
 209 main(int argc, char *argv[])
 210 {
 211         hex_print("\n\t", "Hello, World!\n", 14);
 212         printf("\n");
 213         hex_and_ascii_print("\n\t", "Hello, World!\n", 14);
 214         printf("\n");
 215         ascii_print("Hello, World!\n", 14);
 216         printf("\n");
 217 #define TMSG "Now is the winter of our discontent...\n"
 218         hex_print_with_offset("\n\t", TMSG, sizeof(TMSG) - 1, 0x100);
 219         printf("\n");
 220         hex_and_ascii_print_with_offset("\n\t", TMSG, sizeof(TMSG) - 1, 0x100);
 221         printf("\n");
 222         exit(0);
 223 }
 224 #endif /* MAIN */