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
|
/*
* Copyright (c) 1988, 1992 The University of Utah and the Center
* for Software Science (CSS).
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Center for Software Science of the University of Utah Computer
* Science Department. CSS requests users of this software to return
* to css-dist@cs.utah.edu any improvements that they make and grant
* CSS redistribution rights.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)bpf.c 8.1 (Berkeley) 6/4/93
*
* From: Utah Hdr: bpf.c 3.1 92/07/06
* Author: Jeff Forys, University of Utah CSS
*/
#ifndef lint
#if 0
static const char sccsid[] = "@(#)bpf.c 8.1 (Berkeley) 6/4/93";
#endif
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <net/if.h>
#include <net/bpf.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include "defs.h"
#include "pathnames.h"
static int BpfFd = -1;
static unsigned BpfLen = 0;
static u_int8_t *BpfPkt = NULL;
/*
** BpfOpen -- Open and initialize a BPF device.
**
** Parameters:
** None.
**
** Returns:
** File descriptor of opened BPF device (for select() etc).
**
** Side Effects:
** If an error is encountered, the program terminates here.
*/
int
BpfOpen(void)
{
struct ifreq ifr;
char bpfdev[32];
int n = 0;
/*
* Open the first available BPF device.
*/
do {
(void) sprintf(bpfdev, _PATH_BPF, n++);
BpfFd = open(bpfdev, O_RDWR);
} while (BpfFd < 0 && (errno == EBUSY || errno == EPERM));
if (BpfFd < 0) {
syslog(LOG_ERR, "bpf: no available devices: %m");
Exit(0);
}
/*
* Set interface name for bpf device, get data link layer
* type and make sure it's type Ethernet.
*/
(void) strncpy(ifr.ifr_name, IntfName, sizeof(ifr.ifr_name));
if (ioctl(BpfFd, BIOCSETIF, (caddr_t)&ifr) < 0) {
syslog(LOG_ERR, "bpf: ioctl(BIOCSETIF,%s): %m", IntfName);
Exit(0);
}
/*
* Make sure we are dealing with an Ethernet device.
*/
if (ioctl(BpfFd, BIOCGDLT, (caddr_t)&n) < 0) {
syslog(LOG_ERR, "bpf: ioctl(BIOCGDLT): %m");
Exit(0);
}
if (n != DLT_EN10MB) {
syslog(LOG_ERR,"bpf: %s: data-link type %d unsupported",
IntfName, n);
Exit(0);
}
/*
* On read(), return packets immediately (do not buffer them).
*/
n = 1;
if (ioctl(BpfFd, BIOCIMMEDIATE, (caddr_t)&n) < 0) {
syslog(LOG_ERR, "bpf: ioctl(BIOCIMMEDIATE): %m");
Exit(0);
}
/*
* Try to enable the chip/driver's multicast address filter to
* grab our RMP address. If this fails, try promiscuous mode.
* If this fails, there's no way we are going to get any RMP
* packets so just exit here.
*/
#ifdef MSG_EOR
ifr.ifr_addr.sa_len = RMP_ADDRLEN + 2;
#endif
ifr.ifr_addr.sa_family = AF_UNSPEC;
memmove((char *)&ifr.ifr_addr.sa_data[0], &RmpMcastAddr[0], RMP_ADDRLEN);
if (ioctl(BpfFd, BIOCPROMISC, (caddr_t)0) < 0) {
syslog(LOG_ERR, "bpf: can't set promiscuous mode: %m");
Exit(0);
}
/*
* Ask BPF how much buffer space it requires and allocate one.
*/
if (ioctl(BpfFd, BIOCGBLEN, (caddr_t)&BpfLen) < 0) {
syslog(LOG_ERR, "bpf: ioctl(BIOCGBLEN): %m");
Exit(0);
}
if (BpfPkt == NULL)
BpfPkt = (u_int8_t *)malloc(BpfLen);
if (BpfPkt == NULL) {
syslog(LOG_ERR, "bpf: out of memory (%u bytes for bpfpkt)",
BpfLen);
Exit(0);
}
/*
* Write a little program to snarf RMP Boot packets and stuff
* it down BPF's throat (i.e. set up the packet filter).
*/
{
#define RMP ((struct rmp_packet *)0)
static struct bpf_insn bpf_insn[] = {
{ BPF_LD|BPF_B|BPF_ABS, 0, 0, (long)&RMP->hp_llc.dsap },
{ BPF_JMP|BPF_JEQ|BPF_K, 0, 5, IEEE_DSAP_HP },
{ BPF_LD|BPF_H|BPF_ABS, 0, 0, (long)&RMP->hp_llc.cntrl },
{ BPF_JMP|BPF_JEQ|BPF_K, 0, 3, IEEE_CNTL_HP },
{ BPF_LD|BPF_H|BPF_ABS, 0, 0, (long)&RMP->hp_llc.dxsap },
{ BPF_JMP|BPF_JEQ|BPF_K, 0, 1, HPEXT_DXSAP },
{ BPF_RET|BPF_K, 0, 0, RMP_MAX_PACKET },
{ BPF_RET|BPF_K, 0, 0, 0x0 }
};
#undef RMP
static struct bpf_program bpf_pgm = {
sizeof(bpf_insn)/sizeof(bpf_insn[0]), bpf_insn
};
if (ioctl(BpfFd, BIOCSETF, (caddr_t)&bpf_pgm) < 0) {
syslog(LOG_ERR, "bpf: ioctl(BIOCSETF): %m");
Exit(0);
}
}
return(BpfFd);
}
/*
** BPF GetIntfName -- Return the name of a network interface attached to
** the system, or 0 if none can be found. The interface
** must be configured up; the lowest unit number is
** preferred; loopback is ignored.
**
** Parameters:
** errmsg - if no network interface found, *errmsg explains why.
**
** Returns:
** A (static) pointer to interface name, or NULL on error.
**
** Side Effects:
** None.
*/
char *
BpfGetIntfName(char **errmsg)
{
struct ifreq ibuf[8], *ifrp, *ifend, *mp;
struct ifconf ifc;
int fd;
int minunit, n;
char *cp;
static char device[sizeof(ifrp->ifr_name)];
static char errbuf[128] = "No Error!";
if (errmsg != NULL)
*errmsg = errbuf;
if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
(void) strcpy(errbuf, "bpf: socket: %m");
return(NULL);
}
ifc.ifc_len = sizeof ibuf;
ifc.ifc_buf = (caddr_t)ibuf;
if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 ||
ifc.ifc_len < sizeof(struct ifreq)) {
(void) strcpy(errbuf, "bpf: ioctl(SIOCGIFCONF): %m");
return(NULL);
}
ifrp = ibuf;
ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
mp = 0;
minunit = 666;
for (; ifrp < ifend; ++ifrp) {
if (ioctl(fd, SIOCGIFFLAGS, (char *)ifrp) < 0) {
(void) strcpy(errbuf, "bpf: ioctl(SIOCGIFFLAGS): %m");
return(NULL);
}
/*
* If interface is down or this is the loopback interface,
* ignore it.
*/
if ((ifrp->ifr_flags & IFF_UP) == 0 ||
#ifdef IFF_LOOPBACK
(ifrp->ifr_flags & IFF_LOOPBACK))
#else
(strcmp(ifrp->ifr_name, "lo0") == 0))
#endif
continue;
for (cp = ifrp->ifr_name; !isdigit(*cp); ++cp)
;
n = atoi(cp);
if (n < minunit) {
minunit = n;
mp = ifrp;
}
}
(void) close(fd);
if (mp == 0) {
(void) strcpy(errbuf, "bpf: no interfaces found");
return(NULL);
}
(void) strcpy(device, mp->ifr_name);
return(device);
}
/*
** BpfRead -- Read packets from a BPF device and fill in `rconn'.
**
** Parameters:
** rconn - filled in with next packet.
** doread - is True if we can issue a read() syscall.
**
** Returns:
** True if `rconn' contains a new packet, False otherwise.
**
** Side Effects:
** None.
*/
int
BpfRead(RMPCONN *rconn, int doread)
{
int datlen, caplen, hdrlen;
static u_int8_t *bp = NULL, *ep = NULL;
int cc;
/*
* The read() may block, or it may return one or more packets.
* We let the caller decide whether or not we can issue a read().
*/
if (doread) {
if ((cc = read(BpfFd, (char *)BpfPkt, (int)BpfLen)) < 0) {
syslog(LOG_ERR, "bpf: read: %m");
return(0);
} else {
bp = BpfPkt;
ep = BpfPkt + cc;
}
}
#define bhp ((struct bpf_hdr *)bp)
/*
* If there is a new packet in the buffer, stuff it into `rconn'
* and return a success indication.
*/
if (bp < ep) {
datlen = bhp->bh_datalen;
caplen = bhp->bh_caplen;
hdrlen = bhp->bh_hdrlen;
if (caplen != datlen)
syslog(LOG_ERR,
"bpf: short packet dropped (%d of %d bytes)",
caplen, datlen);
else if (caplen > sizeof(struct rmp_packet))
syslog(LOG_ERR, "bpf: large packet dropped (%d bytes)",
caplen);
else {
rconn->rmplen = caplen;
memmove((char *)&rconn->tstamp, (char *)&bhp->bh_tstamp,
sizeof(struct timeval));
memmove((char *)&rconn->rmp, (char *)bp + hdrlen, caplen);
}
bp += BPF_WORDALIGN(caplen + hdrlen);
return(1);
}
#undef bhp
return(0);
}
/*
** BpfWrite -- Write packet to BPF device.
**
** Parameters:
** rconn - packet to send.
**
** Returns:
** True if write succeeded, False otherwise.
**
** Side Effects:
** None.
*/
int
BpfWrite(RMPCONN *rconn)
{
if (write(BpfFd, (char *)&rconn->rmp, rconn->rmplen) < 0) {
syslog(LOG_ERR, "write: %s: %m", EnetStr(rconn));
return(0);
}
return(1);
}
/*
** BpfClose -- Close a BPF device.
**
** Parameters:
** None.
**
** Returns:
** Nothing.
**
** Side Effects:
** None.
*/
void
BpfClose(void)
{
struct ifreq ifr;
if (BpfPkt != NULL) {
free((char *)BpfPkt);
BpfPkt = NULL;
}
if (BpfFd == -1)
return;
#ifdef MSG_EOR
ifr.ifr_addr.sa_len = RMP_ADDRLEN + 2;
#endif
ifr.ifr_addr.sa_family = AF_UNSPEC;
memmove((char *)&ifr.ifr_addr.sa_data[0], &RmpMcastAddr[0], RMP_ADDRLEN);
if (ioctl(BpfFd, SIOCDELMULTI, (caddr_t)&ifr) < 0)
(void) ioctl(BpfFd, BIOCPROMISC, (caddr_t)0);
(void) close(BpfFd);
BpfFd = -1;
}
|