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The Android Open Source Projectf7c54212009-03-03 19:29:22 -08001/*
2 * dhcpcd - DHCP client daemon
Dmitry Shmidte86eee12011-01-24 16:27:51 -08003 * Copyright (c) 2006-2008 Roy Marples <roy@marples.name>
The Android Open Source Projectf7c54212009-03-03 19:29:22 -08004 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#ifndef BPF_ETHCOOK
28# define BPF_ETHCOOK 0
29#endif
30#ifndef BPF_WHOLEPACKET
31# define BPF_WHOLEPACKET ~0U
32#endif
33static const struct bpf_insn const arp_bpf_filter [] = {
34#ifndef BPF_SKIPTYPE
35 /* Make sure this is an ARP packet... */
36 BPF_STMT(BPF_LD + BPF_H + BPF_ABS, 12),
37 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ETHERTYPE_ARP, 0, 3),
38#endif
39 /* Make sure this is an ARP REQUEST... */
40 BPF_STMT(BPF_LD + BPF_H + BPF_ABS, 20 + BPF_ETHCOOK),
41 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ARPOP_REQUEST, 2, 0),
42 /* or ARP REPLY... */
43 BPF_STMT(BPF_LD + BPF_H + BPF_ABS, 20 + BPF_ETHCOOK),
44 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ARPOP_REPLY, 0, 1),
45 /* If we passed all the tests, ask for the whole packet. */
46 BPF_STMT(BPF_RET + BPF_K, BPF_WHOLEPACKET),
47 /* Otherwise, drop it. */
48 BPF_STMT(BPF_RET + BPF_K, 0),
49};
50static const size_t arp_bpf_filter_len =
51 sizeof(arp_bpf_filter) / sizeof(arp_bpf_filter[0]);
52
53
54/* dhcp_bpf_filter taken from bpf.c in dhcp-3.1.0
55 *
56 * Copyright (c) 2004,2007 by Internet Systems Consortium, Inc. ("ISC")
57 * Copyright (c) 1996-2003 by Internet Software Consortium
58 *
59 * Permission to use, copy, modify, and distribute this software for any
60 * purpose with or without fee is hereby granted, provided that the above
61 * copyright notice and this permission notice appear in all copies.
62 *
63 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
64 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
65 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
66 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
67 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
68 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
69 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
70 *
71 * Internet Systems Consortium, Inc.
72 * 950 Charter Street
73 * Redwood City, CA 94063
74 * <info@isc.org>
75 * http://www.isc.org/
76 */
77
78static const struct bpf_insn const dhcp_bpf_filter [] = {
79#ifndef BPF_SKIPTYPE
80 /* Make sure this is an IP packet... */
81 BPF_STMT(BPF_LD + BPF_H + BPF_ABS, 12),
82 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ETHERTYPE_IP, 0, 8),
83#endif
84 /* Make sure it's a UDP packet... */
85 BPF_STMT(BPF_LD + BPF_B + BPF_ABS, 23 + BPF_ETHCOOK),
86 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, IPPROTO_UDP, 0, 6),
87 /* Make sure this isn't a fragment... */
88 BPF_STMT(BPF_LD + BPF_H + BPF_ABS, 20 + BPF_ETHCOOK),
89 BPF_JUMP(BPF_JMP + BPF_JSET + BPF_K, 0x1fff, 4, 0),
90 /* Get the IP header length... */
91 BPF_STMT(BPF_LDX + BPF_B + BPF_MSH, 14 + BPF_ETHCOOK),
92 /* Make sure it's to the right port... */
93 BPF_STMT(BPF_LD + BPF_H + BPF_IND, 16 + BPF_ETHCOOK),
94 BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, DHCP_CLIENT_PORT, 0, 1),
95 /* If we passed all the tests, ask for the whole packet. */
96 BPF_STMT(BPF_RET + BPF_K, BPF_WHOLEPACKET),
97 /* Otherwise, drop it. */
98 BPF_STMT(BPF_RET + BPF_K, 0),
99};
100static const size_t dhcp_bpf_filter_len =
101 sizeof(dhcp_bpf_filter) / sizeof(dhcp_bpf_filter[0]);