287 lines
9.9 KiB
C
287 lines
9.9 KiB
C
/* lint -save -library Flexelint comment for external headers */
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/*-
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* Copyright (c) 2001 Charles Mott <cm@linktel.net>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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/*
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* Alias.h defines the outside world interfaces for the packet aliasing
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* software.
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*
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* This software is placed into the public domain with no restrictions on its
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* distribution.
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*/
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#ifndef _ALIAS_H_
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#define _ALIAS_H_
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#include <netinet/in_systm.h>
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#include <netinet/in.h>
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#include <netinet/ip.h>
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#define LIBALIAS_BUF_SIZE 128
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#ifdef _KERNEL
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/*
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* The kernel version of libalias does not support these features.
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*/
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#define NO_FW_PUNCH
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#define NO_USE_SOCKETS
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#endif
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/*
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* The external interface to libalias, the packet aliasing engine.
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*
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* There are two sets of functions:
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*
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* PacketAlias*() the old API which doesn't take an instance pointer
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* and therefore can only have one packet engine at a time.
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*
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* LibAlias*() the new API which takes as first argument a pointer to
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* the instance of the packet aliasing engine.
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*
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* The functions otherwise correspond to each other one for one, except
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* for the LibAliasUnaliasOut()/PacketUnaliasOut() function which were
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* were misnamed in the old API.
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*/
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/*
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* The instance structure
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*/
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struct libalias;
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/*
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* An anonymous structure, a pointer to which is returned from
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* PacketAliasRedirectAddr(), PacketAliasRedirectPort() or
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* PacketAliasRedirectProto(), passed to PacketAliasAddServer(),
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* and freed by PacketAliasRedirectDelete().
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*/
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struct alias_link;
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/* OLD API */
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/* Initialization and control functions. */
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void PacketAliasInit(void);
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void PacketAliasSetAddress(struct in_addr _addr);
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void PacketAliasSetFWBase(unsigned int _base, unsigned int _num);
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void PacketAliasSetSkinnyPort(unsigned int _port);
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unsigned int
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PacketAliasSetMode(unsigned int _flags, unsigned int _mask);
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void PacketAliasUninit(void);
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/* Packet Handling functions. */
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int PacketAliasIn(char *_ptr, int _maxpacketsize);
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int PacketAliasOut(char *_ptr, int _maxpacketsize);
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int PacketUnaliasOut(char *_ptr, int _maxpacketsize);
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/* Port and address redirection functions. */
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int
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PacketAliasAddServer(struct alias_link *_lnk,
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struct in_addr _addr, unsigned short _port);
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struct alias_link *
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PacketAliasRedirectAddr(struct in_addr _src_addr,
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struct in_addr _alias_addr);
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int PacketAliasRedirectDynamic(struct alias_link *_lnk);
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void PacketAliasRedirectDelete(struct alias_link *_lnk);
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struct alias_link *
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PacketAliasRedirectPort(struct in_addr _src_addr,
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unsigned short _src_port, struct in_addr _dst_addr,
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unsigned short _dst_port, struct in_addr _alias_addr,
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unsigned short _alias_port, unsigned char _proto);
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struct alias_link *
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PacketAliasRedirectProto(struct in_addr _src_addr,
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struct in_addr _dst_addr, struct in_addr _alias_addr,
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unsigned char _proto);
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/* Fragment Handling functions. */
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void PacketAliasFragmentIn(char *_ptr, char *_ptr_fragment);
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char *PacketAliasGetFragment(char *_ptr);
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int PacketAliasSaveFragment(char *_ptr);
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/* Miscellaneous functions. */
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int PacketAliasCheckNewLink(void);
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unsigned short
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PacketAliasInternetChecksum(unsigned short *_ptr, int _nbytes);
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void PacketAliasSetTarget(struct in_addr _target_addr);
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/* Transparent proxying routines. */
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int PacketAliasProxyRule(const char *_cmd);
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/* NEW API */
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/* Initialization and control functions. */
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struct libalias *LibAliasInit(struct libalias *);
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void LibAliasSetAddress(struct libalias *, struct in_addr _addr);
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void LibAliasSetFWBase(struct libalias *, unsigned int _base, unsigned int _num);
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void LibAliasSetSkinnyPort(struct libalias *, unsigned int _port);
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unsigned int
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LibAliasSetMode(struct libalias *, unsigned int _flags, unsigned int _mask);
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void LibAliasUninit(struct libalias *);
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/* Packet Handling functions. */
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int LibAliasIn (struct libalias *, char *_ptr, int _maxpacketsize);
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int LibAliasOut(struct libalias *, char *_ptr, int _maxpacketsize);
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int LibAliasOutTry(struct libalias *, char *_ptr, int _maxpacketsize, int _create);
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int LibAliasUnaliasOut(struct libalias *, char *_ptr, int _maxpacketsize);
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/* Port and address redirection functions. */
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int
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LibAliasAddServer(struct libalias *, struct alias_link *_lnk,
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struct in_addr _addr, unsigned short _port);
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struct alias_link *
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LibAliasRedirectAddr(struct libalias *, struct in_addr _src_addr,
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struct in_addr _alias_addr);
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int LibAliasRedirectDynamic(struct libalias *, struct alias_link *_lnk);
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void LibAliasRedirectDelete(struct libalias *, struct alias_link *_lnk);
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struct alias_link *
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LibAliasRedirectPort(struct libalias *, struct in_addr _src_addr,
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unsigned short _src_port, struct in_addr _dst_addr,
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unsigned short _dst_port, struct in_addr _alias_addr,
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unsigned short _alias_port, unsigned char _proto);
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struct alias_link *
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LibAliasRedirectProto(struct libalias *, struct in_addr _src_addr,
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struct in_addr _dst_addr, struct in_addr _alias_addr,
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unsigned char _proto);
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/* Fragment Handling functions. */
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void LibAliasFragmentIn(struct libalias *, char *_ptr, char *_ptr_fragment);
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char *LibAliasGetFragment(struct libalias *, char *_ptr);
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int LibAliasSaveFragment(struct libalias *, char *_ptr);
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/* Miscellaneous functions. */
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int LibAliasCheckNewLink(struct libalias *);
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unsigned short
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LibAliasInternetChecksum(struct libalias *, unsigned short *_ptr, int _nbytes);
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void LibAliasSetTarget(struct libalias *, struct in_addr _target_addr);
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/* Transparent proxying routines. */
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int LibAliasProxyRule(struct libalias *, const char *_cmd);
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/* Module handling API */
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int LibAliasLoadModule(char *);
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int LibAliasUnLoadAllModule(void);
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int LibAliasRefreshModules(void);
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/* Mbuf helper function. */
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struct mbuf *m_megapullup(struct mbuf *, int);
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/*
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* Mode flags and other constants.
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*/
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/* Mode flags, set using PacketAliasSetMode() */
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/*
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* If PKT_ALIAS_LOG is set, a message will be printed to /var/log/alias.log
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* every time a link is created or deleted. This is useful for debugging.
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*/
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#define PKT_ALIAS_LOG 0x01
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/*
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* If PKT_ALIAS_DENY_INCOMING is set, then incoming connections (e.g. to ftp,
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* telnet or web servers will be prevented by the aliasing mechanism.
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*/
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#define PKT_ALIAS_DENY_INCOMING 0x02
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/*
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* If PKT_ALIAS_SAME_PORTS is set, packets will be attempted sent from the
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* same port as they originated on. This allows e.g. rsh to work *99% of the
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* time*, but _not_ 100% (it will be slightly flakey instead of not working
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* at all). This mode bit is set by PacketAliasInit(), so it is a default
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* mode of operation.
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*/
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#define PKT_ALIAS_SAME_PORTS 0x04
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/*
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* If PKT_ALIAS_USE_SOCKETS is set, then when partially specified links (e.g.
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* destination port and/or address is zero), the packet aliasing engine will
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* attempt to allocate a socket for the aliasing port it chooses. This will
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* avoid interference with the host machine. Fully specified links do not
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* require this. This bit is set after a call to PacketAliasInit(), so it is
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* a default mode of operation.
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*/
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#ifndef NO_USE_SOCKETS
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#define PKT_ALIAS_USE_SOCKETS 0x08
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#endif
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/*-
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* If PKT_ALIAS_UNREGISTERED_ONLY is set, then only packets with
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* unregistered source addresses will be aliased. Private
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* addresses are those in the following ranges:
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*
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* 10.0.0.0 -> 10.255.255.255
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* 172.16.0.0 -> 172.31.255.255
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* 192.168.0.0 -> 192.168.255.255
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*/
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#define PKT_ALIAS_UNREGISTERED_ONLY 0x10
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/*
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* If PKT_ALIAS_RESET_ON_ADDR_CHANGE is set, then the table of dynamic
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* aliasing links will be reset whenever PacketAliasSetAddress() changes the
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* default aliasing address. If the default aliasing address is left
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* unchanged by this function call, then the table of dynamic aliasing links
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* will be left intact. This bit is set after a call to PacketAliasInit().
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*/
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#define PKT_ALIAS_RESET_ON_ADDR_CHANGE 0x20
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#ifndef NO_FW_PUNCH
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/*
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* If PKT_ALIAS_PUNCH_FW is set, active FTP and IRC DCC connections will
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* create a 'hole' in the firewall to allow the transfers to work. The
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* ipfw rule number that the hole is created with is controlled by
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* PacketAliasSetFWBase(). The hole will be attached to that
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* particular alias_link, so when the link goes away the hole is deleted.
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*/
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#define PKT_ALIAS_PUNCH_FW 0x100
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#endif
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/*
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* If PKT_ALIAS_PROXY_ONLY is set, then NAT will be disabled and only
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* transparent proxying is performed.
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*/
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#define PKT_ALIAS_PROXY_ONLY 0x40
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/*
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* If PKT_ALIAS_REVERSE is set, the actions of PacketAliasIn() and
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* PacketAliasOut() are reversed.
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*/
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#define PKT_ALIAS_REVERSE 0x80
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/* Function return codes. */
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#define PKT_ALIAS_ERROR -1
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#define PKT_ALIAS_OK 1
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#define PKT_ALIAS_IGNORED 2
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#define PKT_ALIAS_UNRESOLVED_FRAGMENT 3
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#define PKT_ALIAS_FOUND_HEADER_FRAGMENT 4
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#endif /* !_ALIAS_H_ */
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/* lint -restore */
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