alias.h revision 145926
174778Sbrian/* lint -save -library Flexelint comment for external headers */ 226026Sbrian 374778Sbrian/*- 485964Sbrian * Copyright (c) 2001 Charles Mott <cm@linktel.net> 577701Sbrian * All rights reserved. 677701Sbrian * 777701Sbrian * Redistribution and use in source and binary forms, with or without 877701Sbrian * modification, are permitted provided that the following conditions 977701Sbrian * are met: 1077701Sbrian * 1. Redistributions of source code must retain the above copyright 1177701Sbrian * notice, this list of conditions and the following disclaimer. 1277701Sbrian * 2. Redistributions in binary form must reproduce the above copyright 1377701Sbrian * notice, this list of conditions and the following disclaimer in the 1477701Sbrian * documentation and/or other materials provided with the distribution. 1577701Sbrian * 1677701Sbrian * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 1777701Sbrian * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1877701Sbrian * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1977701Sbrian * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 2077701Sbrian * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2177701Sbrian * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2277701Sbrian * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2377701Sbrian * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2477701Sbrian * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2577701Sbrian * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2677701Sbrian * SUCH DAMAGE. 2777701Sbrian * 2877701Sbrian * $FreeBSD: head/sys/netinet/libalias/alias.h 145926 2005-05-05 20:25:12Z glebius $ 2977701Sbrian */ 3077701Sbrian 3177701Sbrian/*- 3274778Sbrian * Alias.h defines the outside world interfaces for the packet aliasing 3374778Sbrian * software. 3499207Sbrian * 3574778Sbrian * This software is placed into the public domain with no restrictions on its 3674778Sbrian * distribution. 3774778Sbrian */ 3826026Sbrian 3926026Sbrian#ifndef _ALIAS_H_ 4074778Sbrian#define _ALIAS_H_ 4126026Sbrian 42124621Sphk/* 43124621Sphk * The external interface to libalias, the packet aliasing engine. 44124621Sphk * 45124621Sphk * There are two sets of functions: 46124621Sphk * 47124621Sphk * PacketAlias*() the old API which doesn't take an instance pointer 48124621Sphk * and therefore can only have one packet engine at a time. 49124621Sphk * 50127094Sdes * LibAlias*() the new API which takes as first argument a pointer to 51124621Sphk * the instance of the packet aliasing engine. 52124621Sphk * 53124621Sphk * The functions otherwise correspond to each other one for one, except 54127094Sdes * for the LibAliasUnaliasOut()/PacketUnaliasOut() function which were 55124621Sphk * were misnamed in the old API. 56124621Sphk */ 5726026Sbrian 58124621Sphk/* 59124621Sphk * The instance structure 60124621Sphk */ 61124621Sphkstruct libalias; 62124621Sphk 63124621Sphk/* 64124621Sphk * An anonymous structure, a pointer to which is returned from 65124621Sphk * PacketAliasRedirectAddr(), PacketAliasRedirectPort() or 66124621Sphk * PacketAliasRedirectProto(), passed to PacketAliasAddServer(), 67124621Sphk * and freed by PacketAliasRedirectDelete(). 68124621Sphk */ 69127094Sdesstruct alias_link; 70124621Sphk 71124621Sphk 72124621Sphk/* OLD API */ 73124621Sphk 7474778Sbrian/* Initialization and control functions. */ 75127094Sdesvoid PacketAliasInit(void); 76127094Sdesvoid PacketAliasSetAddress(struct in_addr _addr); 77127094Sdesvoid PacketAliasSetFWBase(unsigned int _base, unsigned int _num); 78127094Sdesvoid PacketAliasSetSkinnyPort(unsigned int _port); 7974778Sbrianunsigned int 80127094Sdes PacketAliasSetMode(unsigned int _flags, unsigned int _mask); 81127094Sdesvoid PacketAliasUninit(void); 8227864Sbrian 8374778Sbrian/* Packet Handling functions. */ 84127094Sdesint PacketAliasIn(char *_ptr, int _maxpacketsize); 85127094Sdesint PacketAliasOut(char *_ptr, int _maxpacketsize); 86127094Sdesint PacketUnaliasOut(char *_ptr, int _maxpacketsize); 8727864Sbrian 8874778Sbrian/* Port and address redirection functions. */ 8932377Seivind 9027864Sbrian 91127094Sdesint 92131614SdesPacketAliasAddServer(struct alias_link *_lnk, 93127094Sdes struct in_addr _addr, unsigned short _port); 9474778Sbrianstruct alias_link * 95127094SdesPacketAliasRedirectAddr(struct in_addr _src_addr, 96127094Sdes struct in_addr _alias_addr); 97131614Sdesint PacketAliasRedirectDynamic(struct alias_link *_lnk); 98131614Sdesvoid PacketAliasRedirectDelete(struct alias_link *_lnk); 9974778Sbrianstruct alias_link * 100127094SdesPacketAliasRedirectPort(struct in_addr _src_addr, 101127094Sdes unsigned short _src_port, struct in_addr _dst_addr, 102127094Sdes unsigned short _dst_port, struct in_addr _alias_addr, 103127094Sdes unsigned short _alias_port, unsigned char _proto); 10474778Sbrianstruct alias_link * 105127094SdesPacketAliasRedirectProto(struct in_addr _src_addr, 106127094Sdes struct in_addr _dst_addr, struct in_addr _alias_addr, 107127094Sdes unsigned char _proto); 10827864Sbrian 10974778Sbrian/* Fragment Handling functions. */ 110127094Sdesvoid PacketAliasFragmentIn(char *_ptr, char *_ptr_fragment); 111127094Sdeschar *PacketAliasGetFragment(char *_ptr); 112127094Sdesint PacketAliasSaveFragment(char *_ptr); 11332377Seivind 11474778Sbrian/* Miscellaneous functions. */ 115127094Sdesint PacketAliasCheckNewLink(void); 11674778Sbrianunsigned short 117127094Sdes PacketAliasInternetChecksum(unsigned short *_ptr, int _nbytes); 118127094Sdesvoid PacketAliasSetTarget(struct in_addr _target_addr); 11927864Sbrian 12074778Sbrian/* Transparent proxying routines. */ 121127094Sdesint PacketAliasProxyRule(const char *_cmd); 12227864Sbrian 123124621Sphk/* NEW API */ 124124621Sphk 125124621Sphk/* Initialization and control functions. */ 126127094Sdesstruct libalias *LibAliasInit(struct libalias *); 127127094Sdesvoid LibAliasSetAddress(struct libalias *, struct in_addr _addr); 128127094Sdesvoid LibAliasSetFWBase(struct libalias *, unsigned int _base, unsigned int _num); 129127094Sdesvoid LibAliasSetSkinnyPort(struct libalias *, unsigned int _port); 130124621Sphkunsigned int 131127094Sdes LibAliasSetMode(struct libalias *, unsigned int _flags, unsigned int _mask); 132127094Sdesvoid LibAliasUninit(struct libalias *); 133124621Sphk 134124621Sphk/* Packet Handling functions. */ 135127094Sdesint LibAliasIn (struct libalias *, char *_ptr, int _maxpacketsize); 136127094Sdesint LibAliasOut(struct libalias *, char *_ptr, int _maxpacketsize); 137131566Sphkint LibAliasOutTry(struct libalias *, char *_ptr, int _maxpacketsize, int _create); 138127094Sdesint LibAliasUnaliasOut(struct libalias *, char *_ptr, int _maxpacketsize); 139124621Sphk 140124621Sphk/* Port and address redirection functions. */ 141124621Sphk 142127094Sdesint 143131614SdesLibAliasAddServer(struct libalias *, struct alias_link *_lnk, 144127094Sdes struct in_addr _addr, unsigned short _port); 145124621Sphkstruct alias_link * 146127094SdesLibAliasRedirectAddr(struct libalias *, struct in_addr _src_addr, 147127094Sdes struct in_addr _alias_addr); 148131614Sdesint LibAliasRedirectDynamic(struct libalias *, struct alias_link *_lnk); 149131614Sdesvoid LibAliasRedirectDelete(struct libalias *, struct alias_link *_lnk); 150124621Sphkstruct alias_link * 151127094SdesLibAliasRedirectPort(struct libalias *, struct in_addr _src_addr, 152127094Sdes unsigned short _src_port, struct in_addr _dst_addr, 153127094Sdes unsigned short _dst_port, struct in_addr _alias_addr, 154127094Sdes unsigned short _alias_port, unsigned char _proto); 155124621Sphkstruct alias_link * 156127094SdesLibAliasRedirectProto(struct libalias *, struct in_addr _src_addr, 157127094Sdes struct in_addr _dst_addr, struct in_addr _alias_addr, 158127094Sdes unsigned char _proto); 159124621Sphk 160124621Sphk/* Fragment Handling functions. */ 161127094Sdesvoid LibAliasFragmentIn(struct libalias *, char *_ptr, char *_ptr_fragment); 162127094Sdeschar *LibAliasGetFragment(struct libalias *, char *_ptr); 163127094Sdesint LibAliasSaveFragment(struct libalias *, char *_ptr); 164124621Sphk 165124621Sphk/* Miscellaneous functions. */ 166127094Sdesint LibAliasCheckNewLink(struct libalias *); 167124621Sphkunsigned short 168127094Sdes LibAliasInternetChecksum(struct libalias *, unsigned short *_ptr, int _nbytes); 169127094Sdesvoid LibAliasSetTarget(struct libalias *, struct in_addr _target_addr); 170124621Sphk 171124621Sphk/* Transparent proxying routines. */ 172127094Sdesint LibAliasProxyRule(struct libalias *, const char *_cmd); 173124621Sphk 174124621Sphk 175124621Sphk/* 176124621Sphk * Mode flags and other constants. 177124621Sphk */ 178124621Sphk 179124621Sphk 18074778Sbrian/* Mode flags, set using PacketAliasSetMode() */ 18163899Sarchie 18274778Sbrian/* 18374778Sbrian * If PKT_ALIAS_LOG is set, a message will be printed to /var/log/alias.log 18474778Sbrian * every time a link is created or deleted. This is useful for debugging. 18574778Sbrian */ 186145925Sglebius#ifndef NO_LOGGING 18774778Sbrian#define PKT_ALIAS_LOG 0x01 188145925Sglebius#endif 18927864Sbrian 19074778Sbrian/* 19174778Sbrian * If PKT_ALIAS_DENY_INCOMING is set, then incoming connections (e.g. to ftp, 19274778Sbrian * telnet or web servers will be prevented by the aliasing mechanism. 19374778Sbrian */ 19474778Sbrian#define PKT_ALIAS_DENY_INCOMING 0x02 19559702Sru 19674778Sbrian/* 19774778Sbrian * If PKT_ALIAS_SAME_PORTS is set, packets will be attempted sent from the 19874778Sbrian * same port as they originated on. This allows e.g. rsh to work *99% of the 19974778Sbrian * time*, but _not_ 100% (it will be slightly flakey instead of not working 20074778Sbrian * at all). This mode bit is set by PacketAliasInit(), so it is a default 20174778Sbrian * mode of operation. 20274778Sbrian */ 20374778Sbrian#define PKT_ALIAS_SAME_PORTS 0x04 20444307Sbrian 20574778Sbrian/* 20674778Sbrian * If PKT_ALIAS_USE_SOCKETS is set, then when partially specified links (e.g. 20774778Sbrian * destination port and/or address is zero), the packet aliasing engine will 20874778Sbrian * attempt to allocate a socket for the aliasing port it chooses. This will 20974778Sbrian * avoid interference with the host machine. Fully specified links do not 21074778Sbrian * require this. This bit is set after a call to PacketAliasInit(), so it is 21174778Sbrian * a default mode of operation. 21274778Sbrian */ 213145926Sglebius#ifndef NO_USE_SOCKETS 21474778Sbrian#define PKT_ALIAS_USE_SOCKETS 0x08 215145926Sglebius#endif 21674778Sbrian/*- 21774778Sbrian * If PKT_ALIAS_UNREGISTERED_ONLY is set, then only packets with 21874778Sbrian * unregistered source addresses will be aliased. Private 21974778Sbrian * addresses are those in the following ranges: 22074778Sbrian * 22174778Sbrian * 10.0.0.0 -> 10.255.255.255 22274778Sbrian * 172.16.0.0 -> 172.31.255.255 22374778Sbrian * 192.168.0.0 -> 192.168.255.255 22474778Sbrian */ 22574778Sbrian#define PKT_ALIAS_UNREGISTERED_ONLY 0x10 22627864Sbrian 22774778Sbrian/* 22874778Sbrian * If PKT_ALIAS_RESET_ON_ADDR_CHANGE is set, then the table of dynamic 22974778Sbrian * aliasing links will be reset whenever PacketAliasSetAddress() changes the 23074778Sbrian * default aliasing address. If the default aliasing address is left 23174778Sbrian * unchanged by this function call, then the table of dynamic aliasing links 23274778Sbrian * will be left intact. This bit is set after a call to PacketAliasInit(). 23374778Sbrian */ 23474778Sbrian#define PKT_ALIAS_RESET_ON_ADDR_CHANGE 0x20 23527864Sbrian 23635314Sbrian#ifndef NO_FW_PUNCH 23774778Sbrian/* 23874778Sbrian * If PKT_ALIAS_PUNCH_FW is set, active FTP and IRC DCC connections will 23974778Sbrian * create a 'hole' in the firewall to allow the transfers to work. The 24074778Sbrian * ipfw rule number that the hole is created with is controlled by 24174778Sbrian * PacketAliasSetFWBase(). The hole will be attached to that 24274778Sbrian * particular alias_link, so when the link goes away the hole is deleted. 24374778Sbrian */ 24474778Sbrian#define PKT_ALIAS_PUNCH_FW 0x100 24535314Sbrian#endif 24632377Seivind 24774778Sbrian/* 24874778Sbrian * If PKT_ALIAS_PROXY_ONLY is set, then NAT will be disabled and only 24974778Sbrian * transparent proxying is performed. 25074778Sbrian */ 25174778Sbrian#define PKT_ALIAS_PROXY_ONLY 0x40 25244307Sbrian 25374778Sbrian/* 25474778Sbrian * If PKT_ALIAS_REVERSE is set, the actions of PacketAliasIn() and 25574778Sbrian * PacketAliasOut() are reversed. 25674778Sbrian */ 25774778Sbrian#define PKT_ALIAS_REVERSE 0x80 25844307Sbrian 25974778Sbrian/* Function return codes. */ 26074778Sbrian#define PKT_ALIAS_ERROR -1 26174778Sbrian#define PKT_ALIAS_OK 1 26274778Sbrian#define PKT_ALIAS_IGNORED 2 26374778Sbrian#define PKT_ALIAS_UNRESOLVED_FRAGMENT 3 26474778Sbrian#define PKT_ALIAS_FOUND_HEADER_FRAGMENT 4 26526026Sbrian 266127094Sdes#endif /* !_ALIAS_H_ */ 26774778Sbrian 26874778Sbrian/* lint -restore */ 269