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 #include <config.h>
15
16 #include "netdissect-stdinc.h"
17
18 #include <string.h>
19
20 #include "netdissect.h"
21
22 /* Check for a string but not go beyond length
23 * Return TRUE on match, FALSE otherwise
24 *
25 * Looks at the first few chars up to tl1 ...
26 */
27
28 static int
l_strnstart(netdissect_options * ndo,const char * tstr1,u_int tl1,const char * str2,u_int l2)29 l_strnstart(netdissect_options *ndo, const char *tstr1, u_int tl1,
30 const char *str2, u_int l2)
31 {
32 if (!ND_TTEST_LEN(str2, tl1)) {
33 /*
34 * We don't have tl1 bytes worth of captured data
35 * for the string, so we can't check for this
36 * string.
37 */
38 return 0;
39 }
40 if (tl1 > l2)
41 return 0;
42
43 return (strncmp(tstr1, str2, tl1) == 0 ? 1 : 0);
44 }
45
46 void
beep_print(netdissect_options * ndo,const u_char * bp,u_int length)47 beep_print(netdissect_options *ndo, const u_char *bp, u_int length)
48 {
49
50 ndo->ndo_protocol = "beep";
51 if (l_strnstart(ndo, "MSG", 4, (const char *)bp, length)) /* A REQuest */
52 ND_PRINT(" BEEP MSG");
53 else if (l_strnstart(ndo, "RPY ", 4, (const char *)bp, length))
54 ND_PRINT(" BEEP RPY");
55 else if (l_strnstart(ndo, "ERR ", 4, (const char *)bp, length))
56 ND_PRINT(" BEEP ERR");
57 else if (l_strnstart(ndo, "ANS ", 4, (const char *)bp, length))
58 ND_PRINT(" BEEP ANS");
59 else if (l_strnstart(ndo, "NUL ", 4, (const char *)bp, length))
60 ND_PRINT(" BEEP NUL");
61 else if (l_strnstart(ndo, "SEQ ", 4, (const char *)bp, length))
62 ND_PRINT(" BEEP SEQ");
63 else if (l_strnstart(ndo, "END", 4, (const char *)bp, length))
64 ND_PRINT(" BEEP END");
65 else
66 ND_PRINT(" BEEP (payload or undecoded)");
67 }
68