aboutsummaryrefslogtreecommitdiffstats
path: root/capture-wpcap.c
blob: 618dd58747070373ab272291bb5cdfed31a14dda (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
/* capture-wpcap.c
 * WinPcap-specific interfaces for capturing.  We load WinPcap at run
 * time, so that we only need one Ethereal binary and one Tethereal binary
 * for Windows, regardless of whether WinPcap is installed or not.
 *
 * $Id: capture-wpcap.c,v 1.8 2004/01/05 19:31:42 ulfl Exp $
 *
 * Ethereal - Network traffic analyzer
 * By Gerald Combs <gerald@ethereal.com>
 * Copyright 2001 Gerald Combs
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#ifdef HAVE_LIBPCAP
#include <pcap.h>
#endif

#include <glib.h>
#include <gmodule.h>

#include "pcap-util.h"
#include "pcap-util-int.h"

/* XXX - yes, I know, I should move cppmagic.h to a generic location. */
#include "tools/lemon/cppmagic.h"

gboolean has_wpcap = FALSE;

#ifdef HAVE_LIBPCAP

static char*   (*p_pcap_lookupdev) (char *);
static void    (*p_pcap_close) (pcap_t *);
static int     (*p_pcap_stats) (pcap_t *, struct pcap_stat *);
static int     (*p_pcap_dispatch) (pcap_t *, int, pcap_handler, guchar *);
static int     (*p_pcap_snapshot) (pcap_t *);
static int     (*p_pcap_datalink) (pcap_t *);
static int     (*p_pcap_setfilter) (pcap_t *, struct bpf_program *);
static char*   (*p_pcap_geterr) (pcap_t *);
static int     (*p_pcap_compile) (pcap_t *, struct bpf_program *, char *, int,
			bpf_u_int32);
#ifdef WPCAP_CONSTIFIED
static int     (*p_pcap_lookupnet) (const char *, bpf_u_int32 *, bpf_u_int32 *,
			char *);
static pcap_t* (*p_pcap_open_live) (const char *, int, int, int, char *);
#else
static int     (*p_pcap_lookupnet) (char *, bpf_u_int32 *, bpf_u_int32 *,
			char *);
static pcap_t* (*p_pcap_open_live) (char *, int, int, int, char *);
#endif
static int     (*p_pcap_loop) (pcap_t *, int, pcap_handler, guchar *);
#ifdef HAVE_PCAP_FINDALLDEVS
static int     (*p_pcap_findalldevs) (pcap_if_t **, char *);
static void    (*p_pcap_freealldevs) (pcap_if_t *);
#endif
static const char *(*p_pcap_lib_version) (void);

typedef struct {
	const char	*name;
	gpointer	*ptr;
	gboolean	optional;
} symbol_table_t;

#define SYM(x, y)	{ STRINGIFY(x) , (gpointer) &CONCAT(p_,x), y }

void
load_wpcap(void)
{

	/* These are the symbols I need or want from Wpcap */
	static const symbol_table_t	symbols[] = {
		SYM(pcap_lookupdev, FALSE),
		SYM(pcap_close, FALSE),
		SYM(pcap_stats, FALSE),
		SYM(pcap_dispatch, FALSE),
		SYM(pcap_snapshot, FALSE),
		SYM(pcap_datalink, FALSE),
		SYM(pcap_setfilter, FALSE),
		SYM(pcap_geterr, FALSE),
		SYM(pcap_compile, FALSE),
		SYM(pcap_lookupnet, FALSE),
		SYM(pcap_open_live, FALSE),
		SYM(pcap_loop, FALSE),
#ifdef HAVE_PCAP_FINDALLDEVS
		SYM(pcap_findalldevs, TRUE),
		SYM(pcap_freealldevs, TRUE),
#endif
		SYM(pcap_lib_version, TRUE),
		{ NULL, NULL, FALSE }
	};

	GModule		*wh; /* wpcap handle */
	const symbol_table_t	*sym;

	wh = g_module_open("wpcap", 0);

	if (!wh) {
		return;
	}

	sym = symbols;
	while (sym->name) {
		if (!g_module_symbol(wh, sym->name, sym->ptr)) {
			if (sym->optional) {
				/*
				 * We don't care if it's missing; we just
				 * don't use it.
				 */
				*sym->ptr = NULL;
			} else {
				/*
				 * We require this symbol.
				 */
				return;
			}
		}
		sym++;
	}


	has_wpcap = TRUE;
}

char*
pcap_lookupdev (char *a)
{
	g_assert(has_wpcap);
	return p_pcap_lookupdev(a);
}

void
pcap_close(pcap_t *a)
{
	g_assert(has_wpcap);
	p_pcap_close(a);
}

int
pcap_stats(pcap_t *a, struct pcap_stat *b)
{
	g_assert(has_wpcap);
	return p_pcap_stats(a, b);
}

int
pcap_dispatch(pcap_t *a, int b, pcap_handler c, guchar *d)
{
	g_assert(has_wpcap);
	return p_pcap_dispatch(a, b, c, d);
}


int
pcap_snapshot(pcap_t *a)
{
	g_assert(has_wpcap);
	return p_pcap_snapshot(a);
}


int
pcap_datalink(pcap_t *a)
{
	g_assert(has_wpcap);
	return p_pcap_datalink(a);
}

int
pcap_setfilter(pcap_t *a, struct bpf_program *b)
{
	g_assert(has_wpcap);
	return p_pcap_setfilter(a, b);
}

char*
pcap_geterr(pcap_t *a)
{
	g_assert(has_wpcap);
	return p_pcap_geterr(a);
}

int
pcap_compile(pcap_t *a, struct bpf_program *b, char *c, int d,
            bpf_u_int32 e)
{
	g_assert(has_wpcap);
	return p_pcap_compile(a, b, c, d, e);
}

int
#ifdef WPCAP_CONSTIFIED
pcap_lookupnet(const char *a, bpf_u_int32 *b, bpf_u_int32 *c, char *d)
#else
pcap_lookupnet(char *a, bpf_u_int32 *b, bpf_u_int32 *c, char *d)
#endif
{
	g_assert(has_wpcap);
	return p_pcap_lookupnet(a, b, c, d);
}

pcap_t*
#ifdef WPCAP_CONSTIFIED
pcap_open_live(const char *a, int b, int c, int d, char *e)
#else
pcap_open_live(char *a, int b, int c, int d, char *e)
#endif
{
	g_assert(has_wpcap);
	return p_pcap_open_live(a, b, c, d, e);
}

int
pcap_loop(pcap_t *a, int b, pcap_handler c, guchar *d)
{
	g_assert(has_wpcap);
	return p_pcap_loop(a, b, c, d);
}

#ifdef HAVE_PCAP_FINDALLDEVS
int
pcap_findalldevs(pcap_if_t **a, char *b)
{
	g_assert(has_wpcap && p_pcap_findalldevs != NULL);
	return p_pcap_findalldevs(a, b);
}

void
pcap_freealldevs(pcap_if_t *a)
{
	g_assert(has_wpcap && p_pcap_freealldevs != NULL);
	p_pcap_freealldevs(a);
}
#endif

/*
 * This will use "pcap_findalldevs()" if we have it, otherwise it'll
 * fall back on "pcap_lookupdev()".
 */
GList *
get_interface_list(int *err, char *err_str)
{
	GList  *il = NULL;
	wchar_t *names;
	char *win95names;
	char ascii_name[MAX_WIN_IF_NAME_LEN + 1];
	char ascii_desc[MAX_WIN_IF_NAME_LEN + 1];
	int i, j;

#ifdef HAVE_PCAP_FINDALLDEVS
	if (p_pcap_findalldevs != NULL)
		return get_interface_list_findalldevs(err, err_str);
#endif

	/*
	 * In WinPcap, pcap_lookupdev is implemented by calling
	 * PacketGetAdapterNames.  According to the documentation
	 * I could find:
	 *
	 *	http://winpcap.polito.it/docs/man/html/Packet32_8c.html#a43
	 *
	 * this means that:
	 *
	 * On Windows OT (95, 98, Me), pcap_lookupdev returns a sequence
	 * of bytes consisting of:
	 *
	 *	a sequence of null-terminated ASCII strings (i.e., each
	 *	one is terminated by a single 0 byte), giving the names
	 *	of the interfaces;
	 *
	 *	an empty ASCII string (i.e., a single 0 byte);
	 *
	 *	a sequence of null-terminated ASCII strings, giving the
	 *	descriptions of the interfaces;
	 *
	 *	an empty ASCII string.
	 *
	 * On Windows NT (NT 4.0, W2K, WXP, W2K3, etc.), pcap_lookupdev
	 * returns a sequence of bytes consisting of:
	 *
	 *	a sequence of null-terminated double-byte Unicode strings
	 *	(i.e., each one consits of a sequence of double-byte
	 *	characters, terminated by a double-byte 0), giving the
	 *	names of the interfaces;
	 *
	 *	an empty Unicode string (i.e., a double 0 byte);
	 *
	 *	a sequence of null-terminated ASCII strings, giving the
	 *	descriptions of the interfaces;
	 *
	 *	an empty ASCII string.
	 *
	 * The Nth string in the first sequence is the name of the Nth
	 * adapter; the Nth string in the second sequence is the
	 * description of the Nth adapter.
	 */

	names = (wchar_t *)pcap_lookupdev(err_str);
	i = 0;

	if (names) {
		char* desc = 0;
		int desc_pos = 0;

		if (names[0]<256) {
			/*
			 * If names[0] is less than 256 it means the first
			 * byte is 0.  This implies that we are using Unicode
			 * characters.
			 */
			while (*(names+desc_pos) || *(names+desc_pos-1))
				desc_pos++;
			desc_pos++;	/* Step over the extra '\0' */
			desc = (char*)(names + desc_pos); /* cast *after* addition */

			while (names[i] != 0) {
				/*
				 * Copy the Unicode description to an ASCII
				 * string.
				 */
				j = 0;
				while (*desc != 0) {
					if (j < MAX_WIN_IF_NAME_LEN)
						ascii_desc[j++] = *desc;
					desc++;
				}
				ascii_desc[j] = '\0';
				desc++;

				/*
				 * Copy the Unicode name to an ASCII string.
				 */
				j = 0;
				while (names[i] != 0) {
					if (j < MAX_WIN_IF_NAME_LEN)
					ascii_name[j++] = (char) names[i++];
				}
				ascii_name[j] = '\0';
				i++;
				il = g_list_append(il,
				    if_info_new(ascii_name, ascii_desc));
			}
		} else {
			/*
			 * Otherwise we are in Windows 95/98 and using ASCII
			 * (8-bit) characters.
			 */
			win95names=(char *)names;
			while (*(win95names+desc_pos) || *(win95names+desc_pos-1))
				desc_pos++;
			desc_pos++;	/* Step over the extra '\0' */
			desc = win95names + desc_pos;

			while (win95names[i] != '\0') {
				/*
				 * "&win95names[i]" points to the current
				 * interface name, and "desc" points to
				 * that interface's description.
				 */
				il = g_list_append(il,
				    if_info_new(&win95names[i], desc));

				/*
				 * Skip to the next description.
				 */
				while (*desc != 0)
					desc++;
				desc++;

				/*
				 * Skip to the next name.
				 */
				while (win95names[i] != 0)
					i++;
				i++;
			}
		}
	}

	if (il == NULL) {
		/*
		 * No interfaces found.
		 */
		*err = NO_INTERFACES_FOUND;
	}

	return il;
}

/*
 * Append the version of WinPcap with which we were compiled to a GString.
 */
void
get_compiled_pcap_version(GString *str)
{
	g_string_append(str, "with WinPcap (version unknown)");
}

/*
 * Append the version of WinPcap with which we we're running to a GString.
 */
void
get_runtime_pcap_version(GString *str)
{
	/*
	 * On Windows, we might have been compiled with WinPcap but
	 * might not have it loaded; indicate whether we have it or
	 * not and, if we have it and we have "pcap_lib_version()",
	 * what version we have.
	 */
	if (has_wpcap) {
		g_string_sprintfa(str, "with ");
		if (p_pcap_lib_version != NULL)
			g_string_sprintfa(str, p_pcap_lib_version());
		else
			g_string_append(str, "WinPcap (version unknown)");
	} else
		g_string_append(str, "without WinPcap");
	g_string_append(str, " ");
}

#else /* HAVE_LIBPCAP */

void
load_wpcap(void)
{
	return;
}

/*
 * Append an indication that we were not compiled with WinPcap
 * to a GString.
 */
void
get_compiled_pcap_version(GString *str)
{
	g_string_append(str, "without WinPcap");
}

/*
 * Don't append anything, as we weren't even compiled to use WinPcap.
 */
void
get_runtime_pcap_version(GString *str _U_)
{
}

#endif /* HAVE_LIBPCAP */