xref: /freebsd/usr.sbin/ppp/filter.h (revision ca987d4641cdcd7f27e153db17c5bf064934faf5)
1 /*-
2  * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org>
3  *          based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
4  *                           Internet Initiative Japan, Inc (IIJ)
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 /* Operations - f_srcop, f_dstop */
32 #define	OP_NONE	0
33 #define	OP_EQ	1
34 #define	OP_GT	2
35 #define	OP_LT	3
36 
37 /* srctype or dsttype */
38 #define T_ADDR		0
39 #define T_MYADDR	1
40 #define T_MYADDR6	2
41 #define T_HISADDR	3
42 #define T_HISADDR6	4
43 #define T_DNS0		5
44 #define T_DNS1		6
45 
46 /*
47  * There's a struct filterent for each possible filter rule.  The
48  * layout is designed to minimise size (there are 4 * MAXFILTERS of
49  * them) - which is also conveniently a power of 2 (32 bytes) on
50  * architectures where sizeof(int)==4 (this makes indexing faster).
51  *
52  * Note that there are four free bits in the initial word for future
53  * extensions.
54  */
55 struct filterent {
56   int f_proto;			/* Protocol: getprotoby*() */
57   unsigned f_action : 8;	/* Filtering action: goto or A_... */
58   unsigned f_srcop : 2;		/* Source port operation: OP_... */
59   unsigned f_dstop : 2;		/* Destination port operation: OP_... */
60   unsigned f_srctype : 3;	/* T_ value of src */
61   unsigned f_dsttype : 3;	/* T_ value of dst */
62   unsigned f_estab : 1;		/* Check TCP ACK bit */
63   unsigned f_syn : 1;		/* Check TCP SYN bit */
64   unsigned f_finrst : 1;	/* Check TCP FIN/RST bits */
65   unsigned f_invert : 1;	/* true to complement match */
66   struct ncprange f_src;	/* Source address and mask */
67   struct ncprange f_dst;	/* Destination address and mask */
68   u_short f_srcport;		/* Source port, compared with f_srcop */
69   u_short f_dstport;		/* Destination port, compared with f_dstop */
70   unsigned timeout;		/* Keep alive value for passed packet */
71 };
72 
73 #define	MAXFILTERS	40	/* in each filter set */
74 
75 /* f_action values [0..MAXFILTERS) specify the next filter rule, others are: */
76 #define	A_NONE		(MAXFILTERS)
77 #define	A_PERMIT	(A_NONE+1)
78 #define	A_DENY		(A_PERMIT+1)
79 
80 struct filter {
81   struct filterent rule[MAXFILTERS];	/* incoming packet filter */
82   const char *name;
83   unsigned fragok : 1;
84   unsigned logok : 1;
85 };
86 
87 /* Which filter set */
88 #define FL_IN		0
89 #define FL_OUT		1
90 #define FL_DIAL		2
91 #define FL_KEEP		3
92 
93 struct ipcp;
94 struct cmdargs;
95 
96 extern int filter_Show(struct cmdargs const *);
97 extern int filter_Set(struct cmdargs const *);
98 extern const char * filter_Action2Nam(unsigned);
99 extern const char *filter_Op2Nam(unsigned);
100 extern void filter_AdjustAddr(struct filter *, struct ncpaddr *,
101                               struct ncpaddr *, struct in_addr *);
102