1/*	$NetBSD: pf.c,v 1.11 2009/10/20 00:51:13 snj Exp $	*/
2
3/*
4 * Copyright (c) 1993-95 Mats O Jansson.  All rights reserved.
5 * Copyright (c) 1990 The Regents of the University of California.
6 * All rights reserved.
7 *
8 * This code is partly derived from rarpd.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. The name of the author may not be used to endorse or promote products
19 *    derived from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33#include <sys/cdefs.h>
34#ifndef lint
35__RCSID("$NetBSD: pf.c,v 1.11 2009/10/20 00:51:13 snj Exp $");
36#endif
37
38#include "os.h"
39
40#include <paths.h>
41#include <sys/uio.h>
42#include <net/bpf.h>
43
44#include "mopdef.h"
45#include "pf.h"
46#include "log.h"
47
48/*
49 * Variables
50 */
51
52extern int promisc;
53
54/*
55 * Return information to device.c how to open device.
56 * In this case the driver can handle both Ethernet type II and
57 * IEEE 802.3 frames (SNAP) in a single pfOpen.
58 */
59
60int
61pfTrans(const char *interface)
62{
63	return TRANS_ETHER+TRANS_8023+TRANS_AND;
64}
65
66/*
67 * Open and initialize packet filter.
68 */
69
70int
71pfInit(const char *interface, int mode, u_short protocol, int typ)
72{
73	int	fd;
74	struct ifreq ifr;
75	u_int	dlt;
76	int	immediate;
77	u_int	bufsize;
78	const char *device = _PATH_BPF;
79
80	static struct bpf_insn insns[] = {
81		BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 12),
82		BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0x4711, 4, 0),
83		BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 20),
84		BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0x4711, 0, 3),
85		BPF_STMT(BPF_LD | BPF_H | BPF_ABS, 14),
86		BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, 0xaaaa, 0, 1),
87		BPF_STMT(BPF_RET | BPF_K, 1520),
88		BPF_STMT(BPF_RET | BPF_K, 0),
89	};
90	static struct bpf_program filter = {
91		sizeof insns / sizeof(insns[0]),
92		insns
93	};
94
95	fd = open(device, mode);
96	if (fd < 0) {
97      		mopLogWarn("pfInit: open %s", device);
98		return(-1);
99	}
100
101	/* Set immediate mode so packets are processed as they arrive. */
102	immediate = 1;
103	if (ioctl(fd, BIOCIMMEDIATE, &immediate) < 0) {
104      		mopLogWarn("pfInit: BIOCIMMEDIATE");
105		return(-1);
106	}
107	bufsize = 32768;
108	if (ioctl(fd, BIOCSBLEN, &bufsize) < 0) {
109      		mopLogWarn("pfInit: BIOCSBLEN(%d)", bufsize);
110	}
111	(void) strncpy(ifr.ifr_name, interface, sizeof ifr.ifr_name);
112	if (ioctl(fd, BIOCSETIF, (caddr_t) & ifr) < 0) {
113      		mopLogWarn("pfInit: BIOCSETIF");
114		return(-1);
115	}
116	/* Check that the data link layer is an Ethernet; this code won't work
117	 * with anything else. */
118	if (ioctl(fd, BIOCGDLT, (caddr_t) & dlt) < 0) {
119      		mopLogWarn("pfInit: BIOCGDLT");
120		return(-1);
121	}
122	if (dlt != DLT_EN10MB) {
123      		mopLogWarnX("pfInit: %s is not ethernet", device);
124		return(-1);
125	}
126	if (promisc) {
127		/* Set promiscuous mode. */
128		if (ioctl(fd, BIOCPROMISC, (caddr_t)0) < 0) {
129      			mopLogWarn("pfInit: BIOCPROMISC");
130			return(-1);
131		}
132	}
133	/* Set filter program. */
134	insns[1].k = protocol;
135	insns[3].k = protocol;
136
137	if (ioctl(fd, BIOCSETF, (caddr_t) & filter) < 0) {
138      		mopLogWarn("pfInit: BIOCSETF");
139		return(-1);
140	}
141	return(fd);
142}
143
144/*
145 * Add a Multicast address to the interface
146 */
147
148int
149pfAddMulti(int s, const char *interface, const char *addr)
150{
151	struct ifreq ifr;
152	int	fd;
153
154	strncpy(ifr.ifr_name, interface, sizeof(ifr.ifr_name));
155
156	ifr.ifr_addr.sa_family = AF_UNSPEC;
157	memmove(ifr.ifr_addr.sa_data, addr, 6);
158
159	/*
160	 * open a socket, temporarily, to use for SIOC* ioctls
161	 *
162	 */
163	if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
164		mopLogWarn("pfAddMulti: socket");
165		return(-1);
166	}
167	if (ioctl(fd, SIOCADDMULTI, (caddr_t)&ifr) < 0) {
168		mopLogWarn("pfAddMulti: SIOCADDMULTI");
169		close(fd);
170		return(-1);
171	}
172	close(fd);
173
174	return(0);
175}
176
177/*
178 * Delete a Multicast address from the interface
179 */
180
181int
182pfDelMulti(int s, const char *interface, const char *addr)
183{
184	struct ifreq ifr;
185	int	fd;
186
187	strncpy(ifr.ifr_name, interface, sizeof(ifr.ifr_name));
188
189	ifr.ifr_addr.sa_family = AF_UNSPEC;
190	memmove(ifr.ifr_addr.sa_data, addr, 6);
191
192	/*
193	 * open a socket, temporarily, to use for SIOC* ioctls
194	 *
195	 */
196	if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
197		mopLogWarn("pfDelMulti: socket");
198		return(-1);
199	}
200	if (ioctl(fd, SIOCDELMULTI, (caddr_t)&ifr) < 0) {
201		mopLogWarn("pfAddMulti: SIOCDELMULTI");
202		close(fd);
203		return(-1);
204	}
205	close(fd);
206
207	return(0);
208}
209
210/*
211 * read a packet
212 */
213
214int
215pfRead(int fd, u_char *buf, int len)
216{
217	return(read(fd, buf, len));
218}
219
220/*
221 * write a packet
222 */
223
224int
225pfWrite(int fd, const u_char *buf, int len, int trans)
226{
227
228	struct iovec iov[2];
229
230	switch (trans) {
231	case TRANS_8023:
232		iov[0].iov_base = (caddr_t)__UNCONST(buf);
233		iov[0].iov_len = 22;
234		iov[1].iov_base = (caddr_t)__UNCONST(buf+22);
235		iov[1].iov_len = len-22;
236		break;
237	default:
238		iov[0].iov_base = (caddr_t)__UNCONST(buf);
239		iov[0].iov_len = 14;
240		iov[1].iov_base = (caddr_t)__UNCONST(buf+14);
241		iov[1].iov_len = len-14;
242		break;
243	}
244
245	if (writev(fd, iov, 2) == len)
246		return(len);
247
248	return(-1);
249}
250
251