filter.h revision 65846 
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 65846 2000-09-14 18:01:54Z 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#define P_ESP   7
36#define P_AH    8
37
38/* Operations - f_srcop, f_dstop */
39#define	OP_NONE	0
40#define	OP_EQ	1
41#define	OP_GT	2
42#define	OP_LT	3
43
44/* srctype or dsttype */
45#define T_ADDR		0
46#define T_MYADDR	1
47#define T_HISADDR	2
48#define T_DNS0		3
49#define T_DNS1		4
50
51/*
52 * There's a struct filterent for each possible filter rule.  The
53 * layout is designed to minimise size (there are 4 * MAXFILTERS of
54 * them) - which is also conveniently a power of 2 (32 bytes) on
55 * architectures where sizeof(int)==4 (this makes indexing faster).
56 *
57 * f_action and f_proto only need to be 6 and 3 bits, respectively,
58 * but making them 8 bits allows them to be efficently accessed using
59 * byte operations as well as allowing space for future expansion
60 * (expanding MAXFILTERS or converting f_proto IPPROTO_... values).
61 *
62 * Note that there are four free bits in the initial word for future
63 * extensions.
64 */
65struct filterent {
66  unsigned f_action : 8;		/* Filtering action: goto or A_... */
67  unsigned f_proto : 8;		/* Protocol: P_... */
68  unsigned f_srcop : 2;		/* Source port operation: OP_... */
69  unsigned f_dstop : 2;		/* Destination port operation: OP_... */
70  unsigned f_srctype : 3;	/* T_ value of src */
71  unsigned f_dsttype : 3;	/* T_ value of dst */
72  unsigned f_estab : 1;		/* Check TCP ACK bit */
73  unsigned f_syn : 1;		/* Check TCP SYN bit */
74  unsigned f_finrst : 1;	/* Check TCP FIN/RST bits */
75  unsigned f_invert : 1;	/* true to complement match */
76  struct in_range f_src;	/* Source address and mask */
77  struct in_range f_dst;	/* Destination address and mask */
78  u_short f_srcport;		/* Source port, compared with f_srcop */
79  u_short f_dstport;		/* Destination port, compared with f_dstop */
80  unsigned timeout;		/* Keep alive value for passed packet */
81};
82
83#define	MAXFILTERS	40	/* in each filter set */
84
85/* f_action values [0..MAXFILTERS) specify the next filter rule, others are: */
86#define	A_NONE		(MAXFILTERS)
87#define	A_PERMIT	(A_NONE+1)
88#define	A_DENY		(A_PERMIT+1)
89
90struct filter {
91  struct filterent rule[MAXFILTERS];	/* incoming packet filter */
92  const char *name;
93  unsigned fragok : 1;
94  unsigned logok : 1;
95};
96
97/* Which filter set */
98#define FL_IN		0
99#define FL_OUT		1
100#define FL_DIAL		2
101#define FL_KEEP		3
102
103struct ipcp;
104struct cmdargs;
105
106extern int ParseAddr(struct ipcp *, const char *, struct in_addr *,
107                     struct in_addr *, int *);
108extern int filter_Show(struct cmdargs const *);
109extern int filter_Set(struct cmdargs const *);
110extern const char * filter_Action2Nam(int);
111extern const char *filter_Proto2Nam(int);
112extern const char *filter_Op2Nam(int);
113extern struct in_addr bits2mask(int);
114extern void filter_AdjustAddr(struct filter *, struct in_addr *,
115                              struct in_addr *, struct in_addr [2]);
116