2 * SPDX-License-Identifier: BSD-2-Clause
4 * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org>
5 * based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
6 * Internet Initiative Japan, Inc (IIJ)
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 /* Operations - f_srcop, f_dstop */
39 /* srctype or dsttype */
49 * There's a struct filterent for each possible filter rule. The
50 * layout is designed to minimise size (there are 4 * MAXFILTERS of
51 * them) - which is also conveniently a power of 2 (32 bytes) on
52 * architectures where sizeof(int)==4 (this makes indexing faster).
54 * Note that there are four free bits in the initial word for future
58 int f_proto; /* Protocol: getprotoby*() */
59 unsigned f_action : 8; /* Filtering action: goto or A_... */
60 unsigned f_srcop : 2; /* Source port operation: OP_... */
61 unsigned f_dstop : 2; /* Destination port operation: OP_... */
62 unsigned f_srctype : 3; /* T_ value of src */
63 unsigned f_dsttype : 3; /* T_ value of dst */
64 unsigned f_estab : 1; /* Check TCP ACK bit */
65 unsigned f_syn : 1; /* Check TCP SYN bit */
66 unsigned f_finrst : 1; /* Check TCP FIN/RST bits */
67 unsigned f_invert : 1; /* true to complement match */
68 struct ncprange f_src; /* Source address and mask */
69 struct ncprange f_dst; /* Destination address and mask */
70 u_short f_srcport; /* Source port, compared with f_srcop */
71 u_short f_dstport; /* Destination port, compared with f_dstop */
72 unsigned timeout; /* Keep alive value for passed packet */
75 #define MAXFILTERS 40 /* in each filter set */
77 /* f_action values [0..MAXFILTERS) specify the next filter rule, others are: */
78 #define A_NONE (MAXFILTERS)
79 #define A_PERMIT (A_NONE+1)
80 #define A_DENY (A_PERMIT+1)
83 struct filterent rule[MAXFILTERS]; /* incoming packet filter */
89 /* Which filter set */
98 extern int filter_Show(struct cmdargs const *);
99 extern int filter_Set(struct cmdargs const *);
100 extern const char * filter_Action2Nam(unsigned);
101 extern const char *filter_Op2Nam(unsigned);
102 extern void filter_AdjustAddr(struct filter *, struct ncpaddr *,
103 struct ncpaddr *, struct in_addr *);