filter.h revision 58073 
1/*
2 *	    Written by Toshiharu OHNO (tony-o@iij.ad.jp)
3 *
4 *   Copyright (C) 1993, Internet Initiative Japan, Inc. All rights reserverd.
5 *
6 * Redistribution and use in source and binary forms are permitted
7 * provided that the above copyright notice and this paragraph are
8 * duplicated in all such forms and that any documentation,
9 * advertising materials, and other materials related to such
10 * distribution and use acknowledge that the software was developed
11 * by the Internet Initiative Japan.  The name of the
12 * IIJ may not be used to endorse or promote products derived
13 * from this software without specific prior written permission.
14 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
16 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
17 *
18 * $FreeBSD: head/usr.sbin/ppp/filter.h 58073 2000-03-14 20:11:45Z brian $
19 *
20 *	TODO:
21 */
22
23/* Known protocols - f_proto */
24#define	P_NONE	0
25#define	P_TCP	1
26#define	P_UDP	2
27#define	P_ICMP	3
28#ifdef IPPROTO_OSPFIGP
29#define	P_OSPF	4
30#endif
31#define	P_IGMP	5
32#ifdef IPPROTO_GRE
33#define P_GRE   6
34#endif
35
36/* Operations - f_srcop, f_dstop */
37#define	OP_NONE	0
38#define	OP_EQ	1
39#define	OP_GT	2
40#define	OP_LT	3
41
42/* srctype or dsttype */
43#define T_ADDR		0
44#define T_MYADDR	1
45#define T_HISADDR	2
46#define T_DNS0		3
47#define T_DNS1		4
48
49/*
50 * There's a struct filterent for each possible filter rule.  The
51 * layout is designed to minimise size (there are 4 * MAXFILTERS of
52 * them) - which is also conveniently a power of 2 (32 bytes) on
53 * architectures where sizeof(int)==4 (this makes indexing faster).
54 *
55 * f_action and f_proto only need to be 6 and 3 bits, respectively,
56 * but making them 8 bits allows them to be efficently accessed using
57 * byte operations as well as allowing space for future expansion
58 * (expanding MAXFILTERS or converting f_proto IPPROTO_... values).
59 *
60 * Note that there are four free bits in the initial word for future
61 * extensions.
62 */
63struct filterent {
64  unsigned f_action : 8;		/* Filtering action: goto or A_... */
65  unsigned f_proto : 8;		/* Protocol: P_... */
66  unsigned f_srcop : 2;		/* Source port operation: OP_... */
67  unsigned f_dstop : 2;		/* Destination port operation: OP_... */
68  unsigned f_srctype : 3;	/* T_ value of src */
69  unsigned f_dsttype : 3;	/* T_ value of dst */
70  unsigned f_estab : 1;		/* Check TCP ACK bit */
71  unsigned f_syn : 1;		/* Check TCP SYN bit */
72  unsigned f_finrst : 1;	/* Check TCP FIN/RST bits */
73  unsigned f_invert : 1;	/* true to complement match */
74  struct in_range f_src;	/* Source address and mask */
75  struct in_range f_dst;	/* Destination address and mask */
76  u_short f_srcport;		/* Source port, compared with f_srcop */
77  u_short f_dstport;		/* Destination port, compared with f_dstop */
78};
79
80#define	MAXFILTERS	40	/* in each filter set */
81
82/* f_action values [0..MAXFILTERS) specify the next filter rule, others are: */
83#define	A_NONE		(MAXFILTERS)
84#define	A_PERMIT	(A_NONE+1)
85#define	A_DENY		(A_PERMIT+1)
86
87struct filter {
88  struct filterent rule[MAXFILTERS];	/* incoming packet filter */
89  const char *name;
90  unsigned fragok : 1;
91  unsigned logok : 1;
92};
93
94/* Which filter set */
95#define FL_IN		0
96#define FL_OUT		1
97#define FL_DIAL		2
98#define FL_KEEP		3
99
100struct ipcp;
101struct cmdargs;
102
103extern int ParseAddr(struct ipcp *, const char *, struct in_addr *,
104                     struct in_addr *, int *);
105extern int filter_Show(struct cmdargs const *);
106extern int filter_Set(struct cmdargs const *);
107extern const char * filter_Action2Nam(int);
108extern const char *filter_Proto2Nam(int);
109extern const char *filter_Op2Nam(int);
110extern struct in_addr bits2mask(int);
111extern void filter_AdjustAddr(struct filter *, struct in_addr *,
112                              struct in_addr *, struct in_addr [2]);
113