xref: /freebsd/contrib/tcpdump/print-beep.c (revision f3c5273d315a64826d2149ac453ff8c4583ddbe8)
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_TTEST2(*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 	if (l_strnstart(ndo, "MSG", 4, (const char *)bp, length)) /* A REQuest */
53 		ND_PRINT((ndo, " BEEP MSG"));
54 	else if (l_strnstart(ndo, "RPY ", 4, (const char *)bp, length))
55 		ND_PRINT((ndo, " BEEP RPY"));
56 	else if (l_strnstart(ndo, "ERR ", 4, (const char *)bp, length))
57 		ND_PRINT((ndo, " BEEP ERR"));
58 	else if (l_strnstart(ndo, "ANS ", 4, (const char *)bp, length))
59 		ND_PRINT((ndo, " BEEP ANS"));
60 	else if (l_strnstart(ndo, "NUL ", 4, (const char *)bp, length))
61 		ND_PRINT((ndo, " BEEP NUL"));
62 	else if (l_strnstart(ndo, "SEQ ", 4, (const char *)bp, length))
63 		ND_PRINT((ndo, " BEEP SEQ"));
64 	else if (l_strnstart(ndo, "END", 4, (const char *)bp, length))
65 		ND_PRINT((ndo, " BEEP END"));
66 	else
67 		ND_PRINT((ndo, " BEEP (payload or undecoded)"));
68 }
69