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
|
/*
* $Id: libnet_link_bpf.c,v 1.6 2004/01/28 19:45:00 mike Exp $
*
* libnet
* libnet_link_bpf.c - low-level bpf routines
*
* Copyright (c) 1998 - 2004 Mike D. Schiffman <mike@infonexus.com>
* All rights reserved.
*
* Copyright (c) 1993, 1994, 1995, 1996, 1998
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that: (1) source code distributions
* retain the above copyright notice and this paragraph in its entirety, (2)
* distributions including binary code include the above copyright notice and
* this paragraph in its entirety in the documentation or other materials
* provided with the distribution, and (3) all advertising materials mentioning
* features or use of this software display the following acknowledgement:
* ``This product includes software developed by the University of California,
* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
* the University nor the names of its contributors may be used to endorse
* or promote products derived from this software without specific prior
* written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#include "common.h"
#include <sys/param.h> /* optionally get BSD define */
#if !defined(__OpenBSD__) && !defined(__FreeBSD__)
#include <sys/timeb.h>
#endif
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/time.h>
#include <net/bpf.h>
#include <sys/sysctl.h>
#include <net/route.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include "../include/gnuc.h"
#include "../include/bpf.h"
#ifdef HAVE_OS_PROTO_H
#include "../include/os-proto.h"
#endif
int
libnet_bpf_open(char *err_buf)
{
int i, fd;
char device[] = "/dev/bpf000";
/*
* Go through all the minors and find one that isn't in use.
*/
for (i = 0; i < 1000; i++)
{
snprintf(device, sizeof(device), "/dev/bpf%d", i);
fd = open(device, O_RDWR);
if (fd == -1 && errno == EBUSY)
{
/*
* Device is busy.
*/
continue;
}
else
{
/*
* Either we've got a valid file descriptor, or errno is not
* EBUSY meaning we've probably run out of devices.
*/
break;
}
}
if (fd == -1)
{
snprintf(err_buf, LIBNET_ERRBUF_SIZE, "%s(): open(): (%s): %s",
__func__, device, strerror(errno));
}
return (fd);
}
int
libnet_open_link(libnet_t *l)
{
struct ifreq ifr;
struct bpf_version bv;
uint v;
#if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT) && !(__APPLE__)
uint spoof_eth_src = 1;
#endif
if (l == NULL)
{
return (-1);
}
if (l->device == NULL)
{
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, "%s(): NULL device",
__func__);
goto bad;
}
l->fd = libnet_bpf_open((char*)l->err_buf);
if (l->fd == -1)
{
goto bad;
}
/*
* Get bpf version.
*/
if (ioctl(l->fd, BIOCVERSION, (caddr_t)&bv) < 0)
{
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, "%s(): BIOCVERSION: %s",
__func__, strerror(errno));
goto bad;
}
if (bv.bv_major != BPF_MAJOR_VERSION || bv.bv_minor < BPF_MINOR_VERSION)
{
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
"%s(): kernel bpf filter out of date", __func__);
goto bad;
}
/*
* Attach network interface to bpf device.
*/
strncpy(ifr.ifr_name, l->device, sizeof(ifr.ifr_name) - 1);
ifr.ifr_name[sizeof(ifr.ifr_name) - 1] = '\0';
if (ioctl(l->fd, BIOCSETIF, (caddr_t)&ifr) == -1)
{
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, "%s(): BIOCSETIF: (%s): %s",
__func__, l->device, strerror(errno));
goto bad;
}
/*
* Get the data link-layer type.
*/
if (ioctl(l->fd, BIOCGDLT, (caddr_t)&v) == -1)
{
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, "%s(): BIOCGDLT: %s",
__func__, strerror(errno));
goto bad;
}
/*
* NetBSD and FreeBSD BPF have an ioctl for enabling/disabling
* automatic filling of the link level source address.
*/
#if defined(BIOCGHDRCMPLT) && defined(BIOCSHDRCMPLT) && !(__APPLE__)
if (ioctl(l->fd, BIOCSHDRCMPLT, &spoof_eth_src) == -1)
{
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, "%s(): BIOCSHDRCMPLT: %s",
__func__, strerror(errno));
goto bad;
}
#endif
/*
* Assign link type and offset.
*/
switch (v)
{
case DLT_SLIP:
l->link_offset = 0x10;
break;
case DLT_RAW:
l->link_offset = 0x0;
break;
case DLT_PPP:
l->link_offset = 0x04;
break;
case DLT_EN10MB:
default:
l->link_offset = 0xe; /* default to ethernet */
break;
}
#if _BSDI_VERSION - 0 >= 199510
switch (v)
{
case DLT_SLIP:
v = DLT_SLIP_BSDOS;
l->link_offset = 0x10;
break;
case DLT_PPP:
v = DLT_PPP_BSDOS;
l->link_offset = 0x04;
break;
}
#endif
l->link_type = v;
return (1);
bad:
if (l->fd > 0)
{
close(l->fd); /* this can fail ok */
}
return (-1);
}
int
libnet_close_link(libnet_t *l)
{
if (close(l->fd) == 0)
{
return (1);
}
else
{
return (-1);
}
}
int
libnet_write_link(libnet_t *l, const uint8_t *packet, uint32_t size)
{
int c;
if (l == NULL)
{
return (-1);
}
c = write(l->fd, packet, size);
if (c != size)
{
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
"%s(): %d bytes written (%s)", __func__, c, strerror(errno));
}
return (c);
}
struct libnet_ether_addr *
libnet_get_hwaddr(libnet_t *l)
{
int mib[6];
size_t len;
int8_t *buf, *next, *end;
struct if_msghdr *ifm;
struct sockaddr_dl *sdl;
mib[0] = CTL_NET;
mib[1] = AF_ROUTE;
mib[2] = 0;
mib[3] = AF_LINK;
mib[4] = NET_RT_IFLIST;
mib[5] = 0;
if (l == NULL)
{
return (NULL);
}
if (l->device == NULL)
{
if (libnet_select_device(l) == -1)
{
/* err msg set in libnet_select_device */
return (NULL);
}
}
if (sysctl(mib, 6, NULL, &len, NULL, 0) == -1)
{
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, "%s(): sysctl(): %s",
__func__, strerror(errno));
return (NULL);
}
buf = (int8_t *)malloc(len);
if (buf == NULL)
{
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, "%s(): malloc(): %s",
__func__, strerror(errno));
return (NULL);
}
if (sysctl(mib, 6, buf, &len, NULL, 0) < 0)
{
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE, "%s(): sysctl(): %s",
__func__, strerror(errno));
free(buf);
return (NULL);
}
end = buf + len;
for (next = buf ; next < end ; next += ifm->ifm_msglen)
{
ifm = (struct if_msghdr *)next;
if (ifm->ifm_version != RTM_VERSION)
continue;
if (ifm->ifm_type == RTM_IFINFO)
{
sdl = (struct sockaddr_dl *)(ifm + 1);
if (sdl->sdl_type != IFT_ETHER
#ifdef IFT_FASTETHER
&& sdl->sdl_type != IFT_FASTETHER
#endif
#ifdef IFT_FASTETHERFX
&& sdl->sdl_type != IFT_FASTETHERFX
#endif
#ifdef IFT_GIGABITETHERNET
&& sdl->sdl_type != IFT_GIGABITETHERNET
#endif
&& sdl->sdl_type != IFT_L2VLAN)
continue;
if (sdl->sdl_nlen == strlen(l->device)
&& strncmp(&sdl->sdl_data[0], l->device, sdl->sdl_nlen) == 0)
{
memcpy(l->link_addr.ether_addr_octet, LLADDR(sdl), ETHER_ADDR_LEN);
break;
}
}
}
free(buf);
if (next == end) {
snprintf(l->err_buf, LIBNET_ERRBUF_SIZE,
"%s(): interface %s of known type not found.",
__func__, l->device);
return NULL;
}
return (&l->link_addr);
}
|