alias.h revision 162674
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 162674 2006-09-26 23:26:53Z piso $ 2977701Sbrian */ 3077701Sbrian 31162674Spiso/* 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 42162674Spiso#include <netinet/in_systm.h> 43162674Spiso#include <netinet/in.h> 44162674Spiso#include <netinet/ip.h> 45162674Spiso 46162674Spiso#define LIBALIAS_BUF_SIZE 128 47145931Sglebius#ifdef _KERNEL 48124621Sphk/* 49145931Sglebius * The kernel version of libalias does not support these features. 50145931Sglebius */ 51145931Sglebius#define NO_FW_PUNCH 52145931Sglebius#define NO_USE_SOCKETS 53145931Sglebius#endif 54145931Sglebius 55145931Sglebius/* 56124621Sphk * The external interface to libalias, the packet aliasing engine. 57124621Sphk * 58124621Sphk * There are two sets of functions: 59124621Sphk * 60124621Sphk * PacketAlias*() the old API which doesn't take an instance pointer 61124621Sphk * and therefore can only have one packet engine at a time. 62124621Sphk * 63127094Sdes * LibAlias*() the new API which takes as first argument a pointer to 64124621Sphk * the instance of the packet aliasing engine. 65124621Sphk * 66124621Sphk * The functions otherwise correspond to each other one for one, except 67127094Sdes * for the LibAliasUnaliasOut()/PacketUnaliasOut() function which were 68124621Sphk * were misnamed in the old API. 69124621Sphk */ 7026026Sbrian 71124621Sphk/* 72124621Sphk * The instance structure 73124621Sphk */ 74124621Sphkstruct libalias; 75124621Sphk 76124621Sphk/* 77124621Sphk * An anonymous structure, a pointer to which is returned from 78124621Sphk * PacketAliasRedirectAddr(), PacketAliasRedirectPort() or 79124621Sphk * PacketAliasRedirectProto(), passed to PacketAliasAddServer(), 80124621Sphk * and freed by PacketAliasRedirectDelete(). 81124621Sphk */ 82127094Sdesstruct alias_link; 83124621Sphk 84124621Sphk 85124621Sphk/* OLD API */ 86124621Sphk 8774778Sbrian/* Initialization and control functions. */ 88127094Sdesvoid PacketAliasInit(void); 89127094Sdesvoid PacketAliasSetAddress(struct in_addr _addr); 90127094Sdesvoid PacketAliasSetFWBase(unsigned int _base, unsigned int _num); 91127094Sdesvoid PacketAliasSetSkinnyPort(unsigned int _port); 9274778Sbrianunsigned int 93127094Sdes PacketAliasSetMode(unsigned int _flags, unsigned int _mask); 94127094Sdesvoid PacketAliasUninit(void); 9527864Sbrian 9674778Sbrian/* Packet Handling functions. */ 97127094Sdesint PacketAliasIn(char *_ptr, int _maxpacketsize); 98127094Sdesint PacketAliasOut(char *_ptr, int _maxpacketsize); 99127094Sdesint PacketUnaliasOut(char *_ptr, int _maxpacketsize); 10027864Sbrian 10174778Sbrian/* Port and address redirection functions. */ 10232377Seivind 10327864Sbrian 104127094Sdesint 105131614SdesPacketAliasAddServer(struct alias_link *_lnk, 106127094Sdes struct in_addr _addr, unsigned short _port); 10774778Sbrianstruct alias_link * 108127094SdesPacketAliasRedirectAddr(struct in_addr _src_addr, 109127094Sdes struct in_addr _alias_addr); 110131614Sdesint PacketAliasRedirectDynamic(struct alias_link *_lnk); 111131614Sdesvoid PacketAliasRedirectDelete(struct alias_link *_lnk); 11274778Sbrianstruct alias_link * 113127094SdesPacketAliasRedirectPort(struct in_addr _src_addr, 114127094Sdes unsigned short _src_port, struct in_addr _dst_addr, 115127094Sdes unsigned short _dst_port, struct in_addr _alias_addr, 116127094Sdes unsigned short _alias_port, unsigned char _proto); 11774778Sbrianstruct alias_link * 118127094SdesPacketAliasRedirectProto(struct in_addr _src_addr, 119127094Sdes struct in_addr _dst_addr, struct in_addr _alias_addr, 120127094Sdes unsigned char _proto); 12127864Sbrian 12274778Sbrian/* Fragment Handling functions. */ 123127094Sdesvoid PacketAliasFragmentIn(char *_ptr, char *_ptr_fragment); 124127094Sdeschar *PacketAliasGetFragment(char *_ptr); 125127094Sdesint PacketAliasSaveFragment(char *_ptr); 12632377Seivind 12774778Sbrian/* Miscellaneous functions. */ 128127094Sdesint PacketAliasCheckNewLink(void); 12974778Sbrianunsigned short 130127094Sdes PacketAliasInternetChecksum(unsigned short *_ptr, int _nbytes); 131127094Sdesvoid PacketAliasSetTarget(struct in_addr _target_addr); 13227864Sbrian 13374778Sbrian/* Transparent proxying routines. */ 134127094Sdesint PacketAliasProxyRule(const char *_cmd); 13527864Sbrian 136124621Sphk/* NEW API */ 137124621Sphk 138124621Sphk/* Initialization and control functions. */ 139127094Sdesstruct libalias *LibAliasInit(struct libalias *); 140127094Sdesvoid LibAliasSetAddress(struct libalias *, struct in_addr _addr); 141127094Sdesvoid LibAliasSetFWBase(struct libalias *, unsigned int _base, unsigned int _num); 142127094Sdesvoid LibAliasSetSkinnyPort(struct libalias *, unsigned int _port); 143124621Sphkunsigned int 144127094Sdes LibAliasSetMode(struct libalias *, unsigned int _flags, unsigned int _mask); 145127094Sdesvoid LibAliasUninit(struct libalias *); 146124621Sphk 147124621Sphk/* Packet Handling functions. */ 148127094Sdesint LibAliasIn (struct libalias *, char *_ptr, int _maxpacketsize); 149127094Sdesint LibAliasOut(struct libalias *, char *_ptr, int _maxpacketsize); 150131566Sphkint LibAliasOutTry(struct libalias *, char *_ptr, int _maxpacketsize, int _create); 151127094Sdesint LibAliasUnaliasOut(struct libalias *, char *_ptr, int _maxpacketsize); 152124621Sphk 153124621Sphk/* Port and address redirection functions. */ 154124621Sphk 155127094Sdesint 156131614SdesLibAliasAddServer(struct libalias *, struct alias_link *_lnk, 157127094Sdes struct in_addr _addr, unsigned short _port); 158124621Sphkstruct alias_link * 159127094SdesLibAliasRedirectAddr(struct libalias *, struct in_addr _src_addr, 160127094Sdes struct in_addr _alias_addr); 161131614Sdesint LibAliasRedirectDynamic(struct libalias *, struct alias_link *_lnk); 162131614Sdesvoid LibAliasRedirectDelete(struct libalias *, struct alias_link *_lnk); 163124621Sphkstruct alias_link * 164127094SdesLibAliasRedirectPort(struct libalias *, struct in_addr _src_addr, 165127094Sdes unsigned short _src_port, struct in_addr _dst_addr, 166127094Sdes unsigned short _dst_port, struct in_addr _alias_addr, 167127094Sdes unsigned short _alias_port, unsigned char _proto); 168124621Sphkstruct alias_link * 169127094SdesLibAliasRedirectProto(struct libalias *, struct in_addr _src_addr, 170127094Sdes struct in_addr _dst_addr, struct in_addr _alias_addr, 171127094Sdes unsigned char _proto); 172124621Sphk 173124621Sphk/* Fragment Handling functions. */ 174127094Sdesvoid LibAliasFragmentIn(struct libalias *, char *_ptr, char *_ptr_fragment); 175127094Sdeschar *LibAliasGetFragment(struct libalias *, char *_ptr); 176127094Sdesint LibAliasSaveFragment(struct libalias *, char *_ptr); 177124621Sphk 178124621Sphk/* Miscellaneous functions. */ 179127094Sdesint LibAliasCheckNewLink(struct libalias *); 180124621Sphkunsigned short 181127094Sdes LibAliasInternetChecksum(struct libalias *, unsigned short *_ptr, int _nbytes); 182127094Sdesvoid LibAliasSetTarget(struct libalias *, struct in_addr _target_addr); 183124621Sphk 184124621Sphk/* Transparent proxying routines. */ 185127094Sdesint LibAliasProxyRule(struct libalias *, const char *_cmd); 186124621Sphk 187162674Spiso/* Module handling API */ 188162674Spisoint LibAliasLoadModule(char *); 189162674Spisoint LibAliasUnLoadAllModule(void); 190162674Spisoint LibAliasRefreshModules(void); 191124621Sphk 192124621Sphk/* 193124621Sphk * Mode flags and other constants. 194124621Sphk */ 195124621Sphk 196124621Sphk 19774778Sbrian/* Mode flags, set using PacketAliasSetMode() */ 19863899Sarchie 19974778Sbrian/* 20074778Sbrian * If PKT_ALIAS_LOG is set, a message will be printed to /var/log/alias.log 20174778Sbrian * every time a link is created or deleted. This is useful for debugging. 20274778Sbrian */ 20374778Sbrian#define PKT_ALIAS_LOG 0x01 20427864Sbrian 20574778Sbrian/* 20674778Sbrian * If PKT_ALIAS_DENY_INCOMING is set, then incoming connections (e.g. to ftp, 20774778Sbrian * telnet or web servers will be prevented by the aliasing mechanism. 20874778Sbrian */ 20974778Sbrian#define PKT_ALIAS_DENY_INCOMING 0x02 21059702Sru 21174778Sbrian/* 21274778Sbrian * If PKT_ALIAS_SAME_PORTS is set, packets will be attempted sent from the 21374778Sbrian * same port as they originated on. This allows e.g. rsh to work *99% of the 21474778Sbrian * time*, but _not_ 100% (it will be slightly flakey instead of not working 21574778Sbrian * at all). This mode bit is set by PacketAliasInit(), so it is a default 21674778Sbrian * mode of operation. 21774778Sbrian */ 21874778Sbrian#define PKT_ALIAS_SAME_PORTS 0x04 21944307Sbrian 22074778Sbrian/* 22174778Sbrian * If PKT_ALIAS_USE_SOCKETS is set, then when partially specified links (e.g. 22274778Sbrian * destination port and/or address is zero), the packet aliasing engine will 22374778Sbrian * attempt to allocate a socket for the aliasing port it chooses. This will 22474778Sbrian * avoid interference with the host machine. Fully specified links do not 22574778Sbrian * require this. This bit is set after a call to PacketAliasInit(), so it is 22674778Sbrian * a default mode of operation. 22774778Sbrian */ 228145926Sglebius#ifndef NO_USE_SOCKETS 22974778Sbrian#define PKT_ALIAS_USE_SOCKETS 0x08 230145926Sglebius#endif 23174778Sbrian/*- 23274778Sbrian * If PKT_ALIAS_UNREGISTERED_ONLY is set, then only packets with 23374778Sbrian * unregistered source addresses will be aliased. Private 23474778Sbrian * addresses are those in the following ranges: 23574778Sbrian * 23674778Sbrian * 10.0.0.0 -> 10.255.255.255 23774778Sbrian * 172.16.0.0 -> 172.31.255.255 23874778Sbrian * 192.168.0.0 -> 192.168.255.255 23974778Sbrian */ 24074778Sbrian#define PKT_ALIAS_UNREGISTERED_ONLY 0x10 24127864Sbrian 24274778Sbrian/* 24374778Sbrian * If PKT_ALIAS_RESET_ON_ADDR_CHANGE is set, then the table of dynamic 24474778Sbrian * aliasing links will be reset whenever PacketAliasSetAddress() changes the 24574778Sbrian * default aliasing address. If the default aliasing address is left 24674778Sbrian * unchanged by this function call, then the table of dynamic aliasing links 24774778Sbrian * will be left intact. This bit is set after a call to PacketAliasInit(). 24874778Sbrian */ 24974778Sbrian#define PKT_ALIAS_RESET_ON_ADDR_CHANGE 0x20 25027864Sbrian 25135314Sbrian#ifndef NO_FW_PUNCH 25274778Sbrian/* 25374778Sbrian * If PKT_ALIAS_PUNCH_FW is set, active FTP and IRC DCC connections will 25474778Sbrian * create a 'hole' in the firewall to allow the transfers to work. The 25574778Sbrian * ipfw rule number that the hole is created with is controlled by 25674778Sbrian * PacketAliasSetFWBase(). The hole will be attached to that 25774778Sbrian * particular alias_link, so when the link goes away the hole is deleted. 25874778Sbrian */ 25974778Sbrian#define PKT_ALIAS_PUNCH_FW 0x100 26035314Sbrian#endif 26132377Seivind 26274778Sbrian/* 26374778Sbrian * If PKT_ALIAS_PROXY_ONLY is set, then NAT will be disabled and only 26474778Sbrian * transparent proxying is performed. 26574778Sbrian */ 26674778Sbrian#define PKT_ALIAS_PROXY_ONLY 0x40 26744307Sbrian 26874778Sbrian/* 26974778Sbrian * If PKT_ALIAS_REVERSE is set, the actions of PacketAliasIn() and 27074778Sbrian * PacketAliasOut() are reversed. 27174778Sbrian */ 27274778Sbrian#define PKT_ALIAS_REVERSE 0x80 27344307Sbrian 27474778Sbrian/* Function return codes. */ 27574778Sbrian#define PKT_ALIAS_ERROR -1 27674778Sbrian#define PKT_ALIAS_OK 1 27774778Sbrian#define PKT_ALIAS_IGNORED 2 27874778Sbrian#define PKT_ALIAS_UNRESOLVED_FRAGMENT 3 27974778Sbrian#define PKT_ALIAS_FOUND_HEADER_FRAGMENT 4 28026026Sbrian 281127094Sdes#endif /* !_ALIAS_H_ */ 28274778Sbrian 28374778Sbrian/* lint -restore */ 284