aboutsummaryrefslogtreecommitdiff
path: root/contrib/isc-dhcp/common/upf.c
blob: 0fa4f884b308733b136476ade47e12ac7fc29742 (plain) (blame)
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
/* upf.c

   Ultrix PacketFilter interface code. */

/*
 * Copyright (c) 1996-2002 Internet Software Consortium.
 * All rights reserved.
 *
 * 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 Internet Software Consortium 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 INTERNET SOFTWARE CONSORTIUM 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 INTERNET SOFTWARE CONSORTIUM 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.
 *
 * This software has been written for the Internet Software Consortium
 * by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
 * To learn more about the Internet Software Consortium, see
 * ``http://www.isc.org/''.  To learn more about Vixie Enterprises,
 * see ``http://www.vix.com''.   To learn more about Nominum, Inc., see
 * ``http://www.nominum.com''.
 */

#ifndef lint
static char copyright[] =
"$Id: upf.c,v 1.21.2.1 2002/11/17 02:27:00 dhankins Exp $ Copyright (c) 1996-2002 The Internet Software Consortium.  All rights reserved.\n";
#endif /* not lint */

#include "dhcpd.h"
#if defined (USE_UPF_SEND) || defined (USE_UPF_RECEIVE)
#include <sys/ioctl.h>
#include <sys/uio.h>

#include <net/pfilt.h>
#include <netinet/in_systm.h>
#include "includes/netinet/ip.h"
#include "includes/netinet/udp.h"
#include "includes/netinet/if_ether.h"

/* Reinitializes the specified interface after an address change.   This
   is not required for packet-filter APIs. */

#ifdef USE_UPF_SEND
void if_reinitialize_send (info)
	struct interface_info *info;
{
}
#endif

#ifdef USE_UPF_RECEIVE
void if_reinitialize_receive (info)
	struct interface_info *info;
{
}
#endif

/* Called by get_interface_list for each interface that's discovered.
   Opens a packet filter for each interface and adds it to the select
   mask. */

int if_register_upf (info)
	struct interface_info *info;
{
	int sock;
	char filename[50];
	int b;
	struct endevp param;

	/* Open a UPF device */
	for (b = 0; 1; b++) {
#ifndef NO_SNPRINTF
		snprintf(filename, sizeof(filename), "/dev/pf/pfilt%d", b);
#else
		sprintf(filename, "/dev/pf/pfilt%d", b);
#endif
		sock = open (filename, O_RDWR, 0);
		if (sock < 0) {
			if (errno == EBUSY) {
				continue;
			} else {
				log_fatal ("Can't find free upf: %m");
			}
		} else {
			break;
		}
	}

	/* Set the UPF device to point at this interface. */
	if (ioctl (sock, EIOCSETIF, info -> ifp) < 0)
		log_fatal ("Can't attach interface %s to upf device %s: %m",
		       info -> name, filename);

	/* Get the hardware address. */
	if (ioctl (sock, EIOCDEVP, &param) < 0)
		log_fatal ("Can't get interface %s hardware address: %m",
		       info -> name);

	/* We only know how to do ethernet. */
	if (param.end_dev_type != ENDT_10MB)	
		log_fatal ("Invalid device type on network interface %s: %d",
		       info -> name, param.end_dev_type);

	if (param.end_addr_len != 6)
		log_fatal ("Invalid hardware address length on %s: %d",
		       info -> name, param.end_addr_len);

	info -> hw_address.hlen = 7;
	info -> hw_address.hbuf [0] = ARPHRD_ETHER;
	memcpy (&info -> hw_address.hbuf [1], param.end_addr, 6);

	return sock;
}
#endif /* USE_UPF_SEND || USE_UPF_RECEIVE */

#ifdef USE_UPF_SEND
void if_register_send (info)
	struct interface_info *info;
{
	/* If we're using the upf API for sending and receiving,
	   we don't need to register this interface twice. */
#ifndef USE_UPF_RECEIVE
	info -> wfdesc = if_register_upf (info, interface);
#else
	info -> wfdesc = info -> rfdesc;
#endif
        if (!quiet_interface_discovery)
		log_info ("Sending on   UPF/%s/%s%s%s",
		      info -> name,
		      print_hw_addr (info -> hw_address.hbuf [0],
				     info -> hw_address.hlen - 1,
				     &info -> hw_address.hbuf [1]),
		      (info -> shared_network ? "/" : ""),
		      (info -> shared_network ?
		       info -> shared_network -> name : ""));
}

void if_deregister_send (info)
	struct interface_info *info;
{
#ifndef USE_UPF_RECEIVE
	close (info -> wfdesc);
#endif
	info -> wfdesc = -1;
        if (!quiet_interface_discovery)
		log_info ("Disabling output on UPF/%s/%s%s%s",
		      info -> name,
		      print_hw_addr (info -> hw_address.hbuf [0],
				     info -> hw_address.hlen - 1,
				     &info -> hw_address.hbuf [1]),
		      (info -> shared_network ? "/" : ""),
		      (info -> shared_network ?
		       info -> shared_network -> name : ""));
}
#endif /* USE_UPF_SEND */

#ifdef USE_UPF_RECEIVE
/* Packet filter program...
   XXX Changes to the filter program may require changes to the constant
   offsets used in if_register_send to patch the UPF program! XXX */


void if_register_receive (info)
	struct interface_info *info;
{
	int flag = 1;
	u_int32_t addr;
	struct enfilter pf;
	u_int32_t bits;

	/* Open a UPF device and hang it on this interface... */
	info -> rfdesc = if_register_upf (info);

	/* Allow the copyall flag to be set... */
	if (ioctl(info -> rfdesc, EIOCALLOWCOPYALL, &flag) < 0)
		log_fatal ("Can't set ALLOWCOPYALL: %m");

	/* Clear all the packet filter mode bits first... */
	flag = (ENHOLDSIG | ENBATCH | ENTSTAMP | ENPROMISC |
		ENNONEXCL | ENCOPYALL);
	if (ioctl (info -> rfdesc, EIOCMBIC, &flag) < 0)
		log_fatal ("Can't clear pfilt bits: %m");

	/* Set the ENBATCH and ENCOPYALL bits... */
	bits = ENBATCH | ENCOPYALL;
	if (ioctl (info -> rfdesc, EIOCMBIS, &bits) < 0)
		log_fatal ("Can't set ENBATCH|ENCOPYALL: %m");

	/* Set up the UPF filter program. */
	/* XXX Unlike the BPF filter program, this one won't work if the
	   XXX IP packet is fragmented or if there are options on the IP
	   XXX header. */
	pf.enf_Priority = 0;
	pf.enf_FilterLen = 0;

	pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHWORD + 6;
	pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT + ENF_CAND;
	pf.enf_Filter [pf.enf_FilterLen++] = htons (ETHERTYPE_IP);
	pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT;
	pf.enf_Filter [pf.enf_FilterLen++] = htons (IPPROTO_UDP);
	pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHWORD + 11;
	pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT + ENF_AND;
	pf.enf_Filter [pf.enf_FilterLen++] = htons (0xFF);
	pf.enf_Filter [pf.enf_FilterLen++] = ENF_CAND;
	pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHWORD + 18;
	pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT + ENF_CAND;
	pf.enf_Filter [pf.enf_FilterLen++] = local_port;

	if (ioctl (info -> rfdesc, EIOCSETF, &pf) < 0)
		log_fatal ("Can't install packet filter program: %m");
        if (!quiet_interface_discovery)
		log_info ("Listening on UPF/%s/%s%s%s",
		      info -> name,
		      print_hw_addr (info -> hw_address.hbuf [0],
				     info -> hw_address.hlen - 1,
				     &info -> hw_address.hbuf [1]),
		      (info -> shared_network ? "/" : ""),
		      (info -> shared_network ?
		       info -> shared_network -> name : ""));
}

void if_deregister_receive (info)
	struct interface_info *info;
{
	close (info -> rfdesc);
	info -> rfdesc = -1;
        if (!quiet_interface_discovery)
		log_info ("Disabling input on UPF/%s/%s%s%s",
		      info -> name,
		      print_hw_addr (info -> hw_address.hbuf [0],
				     info -> hw_address.hlen - 1,
				     &info -> hw_address.hbuf [1]),
		      (info -> shared_network ? "/" : ""),
		      (info -> shared_network ?
		       info -> shared_network -> name : ""));
}
#endif /* USE_UPF_RECEIVE */

#ifdef USE_UPF_SEND
ssize_t send_packet (interface, packet, raw, len, from, to, hto)
	struct interface_info *interface;
	struct packet *packet;
	struct dhcp_packet *raw;
	size_t len;
	struct in_addr from;
	struct sockaddr_in *to;
	struct hardware *hto;
{
	unsigned hbufp = 0, ibufp = 0;
	double hw [4];
	double ip [32];
	struct iovec iov [3];
	int result;
	int fudge;

	if (!strcmp (interface -> name, "fallback"))
		return send_fallback (interface, packet, raw,
				      len, from, to, hto);

	/* Assemble the headers... */
	assemble_hw_header (interface, (unsigned char *)hw, &hbufp, hto);
	assemble_udp_ip_header (interface,
				(unsigned char *)ip, &ibufp, from.s_addr,
				to -> sin_addr.s_addr, to -> sin_port,
				(unsigned char *)raw, len);

	/* Fire it off */
	iov [0].iov_base = ((char *)hw);
	iov [0].iov_len = hbufp;
	iov [1].iov_base = ((char *)ip);
	iov [1].iov_len = ibufp;
	iov [2].iov_base = (char *)raw;
	iov [2].iov_len = len;

	result = writev(interface -> wfdesc, iov, 3);
	if (result < 0)
		log_error ("send_packet: %m");
	return result;
}
#endif /* USE_UPF_SEND */

#ifdef USE_UPF_RECEIVE
ssize_t receive_packet (interface, buf, len, from, hfrom)
	struct interface_info *interface;
	unsigned char *buf;
	size_t len;
	struct sockaddr_in *from;
	struct hardware *hfrom;
{
	int nread;
	int length = 0;
	int offset = 0;
	unsigned char ibuf [1500 + sizeof (struct enstamp)];
	int bufix = 0;

	length = read (interface -> rfdesc, ibuf, sizeof ibuf);
	if (length <= 0)
		return length;

	bufix = sizeof (struct enstamp);
	/* Decode the physical header... */
	offset = decode_hw_header (interface, ibuf, bufix, hfrom);

	/* If a physical layer checksum failed (dunno of any
	   physical layer that supports this, but WTH), skip this
	   packet. */
	if (offset < 0) {
		return 0;
	}

	bufix += offset;
	length -= offset;

	/* Decode the IP and UDP headers... */
	offset = decode_udp_ip_header (interface, ibuf, bufix,
				       from, (unsigned char *)0, length);

	/* If the IP or UDP checksum was bad, skip the packet... */
	if (offset < 0)
		return 0;

	bufix += offset;
	length -= offset;

	/* Copy out the data in the packet... */
	memcpy (buf, &ibuf [bufix], length);
	return length;
}

int can_unicast_without_arp (ip)
	struct interface_info *ip;
{
	return 1;
}

int can_receive_unicast_unconfigured (ip)
	struct interface_info *ip;
{
	return 1;
}

int supports_multiple_interfaces (ip)
	struct interface_info *ip;
{
	return 1;
}

void maybe_setup_fallback ()
{
	isc_result_t status;
	struct interface_info *fbi = (struct interface_info *)0;
	if (setup_fallback (&fbi, MDL)) {
		if_register_fallback (fbi);
		status = omapi_register_io_object ((omapi_object_t *)fbi,
						   if_readsocket, 0,
						   fallback_discard, 0, 0);
		if (status != ISC_R_SUCCESS)
			log_fatal ("Can't register I/O handle for %s: %s",
				   fbi -> name, isc_result_totext (status));
		interface_dereference (&fbi, MDL);
	}
}
#endif