1/*
2 * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * The contents of this file constitute Original Code as defined in and
7 * are subject to the Apple Public Source License Version 1.1 (the
8 * "License").  You may not use this file except in compliance with the
9 * License.  Please obtain a copy of the License at
10 * http://www.apple.com/publicsource and read it before using this file.
11 *
12 * This Original Code and all software distributed under the License are
13 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
14 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
15 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
17 * License for the specific language governing rights and limitations
18 * under the License.
19 *
20 * @APPLE_LICENSE_HEADER_END@
21 */
22/*-
23 * Copyright (c) 2001 Charles Mott <cmott@scientech.com>
24 * All rights reserved.
25 *
26 * Redistribution and use in source and binary forms, with or without
27 * modification, are permitted provided that the following conditions
28 * are met:
29 * 1. Redistributions of source code must retain the above copyright
30 *    notice, this list of conditions and the following disclaimer.
31 * 2. Redistributions in binary form must reproduce the above copyright
32 *    notice, this list of conditions and the following disclaimer in the
33 *    documentation and/or other materials provided with the distribution.
34 *
35 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
36 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
37 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
38 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
39 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
40 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
41 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
42 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
43 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
44 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
45 * SUCH DAMAGE.
46 *
47 * Based upon:
48 * $FreeBSD: src/lib/libalias/alias.h,v 1.12.2.4 2001/08/01 09:36:40 obrien Exp $
49 */
50
51/*-
52 * Alias.h defines the outside world interfaces for the packet aliasing
53 * software.
54 *
55 * This software is placed into the public domain with no restrictions on its
56 * distribution.
57 */
58
59#ifndef _ALIAS_H_
60#define	_ALIAS_H_
61
62/* Alias link representative (incomplete struct) */
63struct alias_link;
64
65/* External interfaces (API) to packet aliasing engine */
66
67/* Initialization and Control */
68    extern void
69    PacketAliasInit(void);
70
71    extern void
72    PacketAliasUninit(void);
73
74    extern void
75    PacketAliasSetAddress(struct in_addr);
76
77    extern unsigned int
78    PacketAliasSetMode(unsigned int, unsigned int);
79
80#ifndef NO_FW_PUNCH
81    extern void
82    PacketAliasSetFWBase(unsigned int, unsigned int);
83#endif
84
85    extern void
86    PacketAliasClampMSS(u_short mss);
87
88/* Packet Handling */
89    extern int
90    PacketAliasIn(char *, int maxpacketsize);
91
92    extern int
93    PacketAliasOut(char *, int maxpacketsize);
94
95    extern int
96    PacketUnaliasOut(char *, int maxpacketsize);
97
98/* Port and Address Redirection */
99    extern struct alias_link *
100    PacketAliasRedirectPort(struct in_addr, u_short,
101                            struct in_addr, u_short,
102                            struct in_addr, u_short,
103                            u_char);
104
105    extern int
106    PacketAliasAddServer(struct alias_link *link,
107                         struct in_addr addr,
108                         u_short port);
109
110    extern struct alias_link *
111    PacketAliasRedirectProto(struct in_addr,
112                             struct in_addr,
113                             struct in_addr,
114                             u_char);
115
116    extern struct alias_link *
117    PacketAliasRedirectAddr(struct in_addr,
118                            struct in_addr);
119
120    extern void
121    PacketAliasRedirectDelete(struct alias_link *);
122
123/* Fragment Handling */
124    extern int
125    PacketAliasSaveFragment(char *);
126
127    extern char *
128    PacketAliasGetFragment(char *);
129
130    extern void
131    PacketAliasFragmentIn(char *, char *);
132
133/* Miscellaneous Functions */
134    extern void
135    PacketAliasSetTarget(struct in_addr addr);
136
137    extern int
138    PacketAliasCheckNewLink(void);
139
140    extern u_short
141    PacketAliasInternetChecksum(u_short *, int);
142
143/* Transparent Proxying */
144    extern int
145    PacketAliasProxyRule(const char *);
146
147
148/********************** Mode flags ********************/
149/* Set these flags using PacketAliasSetMode() */
150
151/* If PKT_ALIAS_LOG is set, a message will be printed to
152	/var/log/alias.log every time a link is created or deleted.  This
153	is useful for debugging */
154#define PKT_ALIAS_LOG 0x01
155
156/* If PKT_ALIAS_DENY_INCOMING is set, then incoming connections (e.g.
157	to ftp, telnet or web servers will be prevented by the aliasing
158	mechanism.  */
159#define PKT_ALIAS_DENY_INCOMING 0x02
160
161/* If PKT_ALIAS_SAME_PORTS is set, packets will be attempted sent from
162	the same port as they originated on.  This allows e.g. rsh to work
163	*99% of the time*, but _not_ 100%.  (It will be slightly flakey
164	instead of not working at all.)  This mode bit is set by
165        PacketAliasInit(), so it is a default mode of operation. */
166#define PKT_ALIAS_SAME_PORTS 0x04
167
168/* If PKT_ALIAS_USE_SOCKETS is set, then when partially specified
169	links (e.g. destination port and/or address is zero), the packet
170	aliasing engine will attempt to allocate a socket for the aliasing
171	port it chooses.  This will avoid interference with the host
172	machine.  Fully specified links do not require this.  This bit
173        is set after a call to PacketAliasInit(), so it is a default
174        mode of operation. */
175#define PKT_ALIAS_USE_SOCKETS 0x08
176
177/* If PKT_ALIAS_UNREGISTERED_ONLY is set, then only packets with
178	unregistered source addresses will be aliased.  Private
179	addresses are those in the following ranges:
180		10.0.0.0     ->   10.255.255.255
181		172.16.0.0   ->   172.31.255.255
182		192.168.0.0  ->   192.168.255.255  */
183#define PKT_ALIAS_UNREGISTERED_ONLY 0x10
184
185/* If PKT_ALIAS_RESET_ON_ADDR_CHANGE is set, then the table of dynamic
186	aliasing links will be reset whenever PacketAliasSetAddress()
187        changes the default aliasing address.  If the default aliasing
188        address is left unchanged by this function call, then the
189        table of dynamic aliasing links will be left intact.  This
190        bit is set after a call to PacketAliasInit(). */
191#define PKT_ALIAS_RESET_ON_ADDR_CHANGE 0x20
192
193#ifndef NO_FW_PUNCH
194/* If PKT_ALIAS_PUNCH_FW is set, active FTP and IRC DCC connections
195   will create a 'hole' in the firewall to allow the transfers to
196   work.  Where (IPFW "line-numbers") the hole is created is
197   controlled by PacketAliasSetFWBase(base, size). The hole will be
198   attached to that particular alias_link, so when the link goes away
199   so do the hole.  */
200#define PKT_ALIAS_PUNCH_FW 0x100
201#endif
202
203/* If PKT_ALIAS_PROXY_ONLY is set, then NAT will be disabled and only
204      transparent proxying performed */
205#define PKT_ALIAS_PROXY_ONLY 0x40
206
207/* If PKT_ALIAS_REVERSE is set, the actions of PacketAliasIn()
208      and PacketAliasOut() are reversed */
209#define PKT_ALIAS_REVERSE 0x80
210
211/* Return Codes */
212#define PKT_ALIAS_ERROR -1
213#define PKT_ALIAS_OK 1
214#define PKT_ALIAS_IGNORED 2
215#define PKT_ALIAS_UNRESOLVED_FRAGMENT 3
216#define PKT_ALIAS_FOUND_HEADER_FRAGMENT 4
217
218#endif
219/* lint -restore */
220