125 lines
4.4 KiB
C
125 lines
4.4 KiB
C
/*-
|
|
* Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org>
|
|
* based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
|
|
* Internet Initiative Japan, Inc (IIJ)
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
/* Known protocols - f_proto */
|
|
#define P_NONE 0
|
|
#define P_TCP 1
|
|
#define P_UDP 2
|
|
#define P_ICMP 3
|
|
#ifdef IPPROTO_OSPFIGP
|
|
#define P_OSPF 4
|
|
#endif
|
|
#define P_IGMP 5
|
|
#ifdef IPPROTO_GRE
|
|
#define P_GRE 6
|
|
#endif
|
|
#define P_ESP 7
|
|
#define P_AH 8
|
|
#define P_IPIP 9
|
|
|
|
/* Operations - f_srcop, f_dstop */
|
|
#define OP_NONE 0
|
|
#define OP_EQ 1
|
|
#define OP_GT 2
|
|
#define OP_LT 3
|
|
|
|
/* srctype or dsttype */
|
|
#define T_ADDR 0
|
|
#define T_MYADDR 1
|
|
#define T_HISADDR 2
|
|
#define T_DNS0 3
|
|
#define T_DNS1 4
|
|
|
|
/*
|
|
* There's a struct filterent for each possible filter rule. The
|
|
* layout is designed to minimise size (there are 4 * MAXFILTERS of
|
|
* them) - which is also conveniently a power of 2 (32 bytes) on
|
|
* architectures where sizeof(int)==4 (this makes indexing faster).
|
|
*
|
|
* f_action and f_proto only need to be 6 and 3 bits, respectively,
|
|
* but making them 8 bits allows them to be efficently accessed using
|
|
* byte operations as well as allowing space for future expansion
|
|
* (expanding MAXFILTERS or converting f_proto IPPROTO_... values).
|
|
*
|
|
* Note that there are four free bits in the initial word for future
|
|
* extensions.
|
|
*/
|
|
struct filterent {
|
|
unsigned f_action : 8; /* Filtering action: goto or A_... */
|
|
unsigned f_proto : 8; /* Protocol: P_... */
|
|
unsigned f_srcop : 2; /* Source port operation: OP_... */
|
|
unsigned f_dstop : 2; /* Destination port operation: OP_... */
|
|
unsigned f_srctype : 3; /* T_ value of src */
|
|
unsigned f_dsttype : 3; /* T_ value of dst */
|
|
unsigned f_estab : 1; /* Check TCP ACK bit */
|
|
unsigned f_syn : 1; /* Check TCP SYN bit */
|
|
unsigned f_finrst : 1; /* Check TCP FIN/RST bits */
|
|
unsigned f_invert : 1; /* true to complement match */
|
|
struct in_range f_src; /* Source address and mask */
|
|
struct in_range f_dst; /* Destination address and mask */
|
|
u_short f_srcport; /* Source port, compared with f_srcop */
|
|
u_short f_dstport; /* Destination port, compared with f_dstop */
|
|
unsigned timeout; /* Keep alive value for passed packet */
|
|
};
|
|
|
|
#define MAXFILTERS 40 /* in each filter set */
|
|
|
|
/* f_action values [0..MAXFILTERS) specify the next filter rule, others are: */
|
|
#define A_NONE (MAXFILTERS)
|
|
#define A_PERMIT (A_NONE+1)
|
|
#define A_DENY (A_PERMIT+1)
|
|
|
|
struct filter {
|
|
struct filterent rule[MAXFILTERS]; /* incoming packet filter */
|
|
const char *name;
|
|
unsigned fragok : 1;
|
|
unsigned logok : 1;
|
|
};
|
|
|
|
/* Which filter set */
|
|
#define FL_IN 0
|
|
#define FL_OUT 1
|
|
#define FL_DIAL 2
|
|
#define FL_KEEP 3
|
|
|
|
struct ipcp;
|
|
struct cmdargs;
|
|
|
|
extern int ParseAddr(struct ipcp *, const char *, struct in_addr *,
|
|
struct in_addr *, int *);
|
|
extern int filter_Show(struct cmdargs const *);
|
|
extern int filter_Set(struct cmdargs const *);
|
|
extern const char * filter_Action2Nam(int);
|
|
extern const char *filter_Proto2Nam(int);
|
|
extern const char *filter_Op2Nam(int);
|
|
extern struct in_addr bits2mask(int);
|
|
extern void filter_AdjustAddr(struct filter *, struct in_addr *,
|
|
struct in_addr *, struct in_addr [2]);
|