contrib/tcpdump/print-beep.c

   1 /*
   2  * Copyright (C) 2000, Richard Sharpe
   3  *
   4  * This software may be distributed either under the terms of the
   5  * BSD-style license that accompanies tcpdump or under the GNU GPL
   6  * version 2 or later.
   7  *
   8  * print-beep.c
   9  *
  10  */
  11
  12 /* \summary: Blocks Extensible Exchange Protocol (BEEP) printer */
  13
  14 #ifdef HAVE_CONFIG_H
  15 #include <config.h>
  16 #endif
  17
  18 #include "netdissect-stdinc.h"
  19
  20 #include <string.h>
  21
  22 #include "netdissect.h"
  23
  24 /* Check for a string but not go beyond length
  25  * Return TRUE on match, FALSE otherwise
  26  *
  27  * Looks at the first few chars up to tl1 ...
  28  */
  29
  30 static int
  31 l_strnstart(netdissect_options *ndo, const char *tstr1, u_int tl1,
  32     const char *str2, u_int l2)
  33 {
  34         if (!ND_TTEST_LEN(str2, tl1)) {
  35                 /*
  36                  * We don't have tl1 bytes worth of captured data
  37                  * for the string, so we can't check for this
  38                  * string.
  39                  */
  40                 return 0;
  41         }
  42         if (tl1 > l2)
  43                 return 0;
  44
  45         return (strncmp(tstr1, str2, tl1) == 0 ? 1 : 0);
  46 }
  47
  48 void
  49 beep_print(netdissect_options *ndo, const u_char *bp, u_int length)
  50 {
  51
  52         ndo->ndo_protocol = "beep";
  53         if (l_strnstart(ndo, "MSG", 4, (const char *)bp, length)) /* A REQuest */
  54                 ND_PRINT(" BEEP MSG");
  55         else if (l_strnstart(ndo, "RPY ", 4, (const char *)bp, length))
  56                 ND_PRINT(" BEEP RPY");
  57         else if (l_strnstart(ndo, "ERR ", 4, (const char *)bp, length))
  58                 ND_PRINT(" BEEP ERR");
  59         else if (l_strnstart(ndo, "ANS ", 4, (const char *)bp, length))
  60                 ND_PRINT(" BEEP ANS");
  61         else if (l_strnstart(ndo, "NUL ", 4, (const char *)bp, length))
  62                 ND_PRINT(" BEEP NUL");
  63         else if (l_strnstart(ndo, "SEQ ", 4, (const char *)bp, length))
  64                 ND_PRINT(" BEEP SEQ");
  65         else if (l_strnstart(ndo, "END", 4, (const char *)bp, length))
  66                 ND_PRINT(" BEEP END");
  67         else
  68                 ND_PRINT(" BEEP (payload or undecoded)");
  69 }