xref: /freebsd/contrib/tcpdump/print-beep.c (revision b64c5a0ace59af62eff52bfe110a521dc73c937b)
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
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
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