xref: /freebsd/contrib/tcpdump/netdissect.c (revision f5147e312f43a9050468de539aeafa072caa1a60)
1 /*
2  * Copyright (c) 1988-1997
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Copyright (c) 1998-2012  Michael Richardson <mcr@tcpdump.org>
6  *      The TCPDUMP project
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that: (1) source code distributions
10  * retain the above copyright notice and this paragraph in its entirety, (2)
11  * distributions including binary code include the above copyright notice and
12  * this paragraph in its entirety in the documentation or other materials
13  * provided with the distribution, and (3) all advertising materials mentioning
14  * features or use of this software display the following acknowledgement:
15  * ``This product includes software developed by the University of California,
16  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
17  * the University nor the names of its contributors may be used to endorse
18  * or promote products derived from this software without specific prior
19  * written permission.
20  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
21  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
22  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
23  */
24 
25 #ifdef HAVE_CONFIG_H
26 #include "config.h"
27 #endif
28 
29 #include <netdissect-stdinc.h>
30 #include "netdissect.h"
31 #include <string.h>
32 #include <stdio.h>
33 
34 #ifdef USE_LIBSMI
35 #include <smi.h>
36 #endif
37 
38 /*
39  * Initialize anything that must be initialized before dissecting
40  * packets.
41  *
42  * This should be called at the beginning of the program; it does
43  * not need to be called, and should not be called, for every
44  * netdissect_options structure.
45  */
46 int
47 nd_init(char *errbuf, size_t errbuf_size)
48 {
49 #ifdef _WIN32
50 	WORD wVersionRequested;
51 	WSADATA wsaData;
52 	int err;
53 
54 	/*
55 	 * Request Winsock 2.2; we expect Winsock 2.
56 	 */
57 	wVersionRequested = MAKEWORD(2, 2);
58 	err = WSAStartup(wVersionRequested, &wsaData);
59 	if (err != 0) {
60 		strlcpy(errbuf, "Attempting to initialize Winsock failed",
61 		    errbuf_size);
62 		return (-1);
63 	}
64 #endif /* _WIN32 */
65 
66 #ifdef USE_LIBSMI
67 	/*
68 	 * XXX - should we just fail if this fails?  Some of the
69 	 * libsmi calls may fail.
70 	 */
71 	smiInit("tcpdump");
72 #endif
73 
74 	/*
75 	 * Clears the error buffer, and uses it so we don't get
76 	 * "unused argument" warnings at compile time.
77 	 */
78 	strlcpy(errbuf, "", errbuf_size);
79 	return (0);
80 }
81 
82 /*
83  * Clean up anything that ndo_init() did.
84  */
85 void
86 nd_cleanup(void)
87 {
88 #ifdef USE_LIBSMI
89 	/*
90 	 * This appears, in libsmi 0.4.8, to do nothing if smiInit()
91 	 * wasn't done or failed, so we call it unconditionally.
92 	 */
93 	smiExit();
94 #endif
95 
96 #ifdef _WIN32
97 	/*
98 	 * Undo the WSAStartup() call above.
99 	 */
100 	WSACleanup();
101 #endif
102 }
103 
104 int
105 nd_have_smi_support(void)
106 {
107 #ifdef USE_LIBSMI
108 	return (1);
109 #else
110 	return (0);
111 #endif
112 }
113 
114 /*
115  * Indicates whether an SMI module has been loaded, so that we can use
116  * libsmi to translate OIDs.
117  */
118 int nd_smi_module_loaded;
119 
120 int
121 nd_load_smi_module(const char *module, char *errbuf, size_t errbuf_size)
122 {
123 #ifdef USE_LIBSMI
124 	if (smiLoadModule(module) == 0) {
125 		snprintf(errbuf, errbuf_size, "could not load MIB module %s",
126 		    module);
127 		return (-1);
128 	}
129 	nd_smi_module_loaded = 1;
130 	return (0);
131 #else
132 	snprintf(errbuf, errbuf_size, "MIB module %s not loaded: no libsmi support",
133 	    module);
134 	return (-1);
135 #endif
136 }
137 
138 const char *
139 nd_smi_version_string(void)
140 {
141 #ifdef USE_LIBSMI
142 	return (smi_version_string);
143 #else
144 	return (NULL);
145 #endif
146 }
147