alias.h revision 124621
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 124621 2004-01-17 10:52:21Z phk $ 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 * 50124621Sphk * 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 54124621Sphk * 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 */ 69124621Sphkstruct alias_link; 70124621Sphk 71124621Sphk 72124621Sphk/* OLD API */ 73124621Sphk 7474778Sbrian/* Initialization and control functions. */ 7574778Sbrianvoid PacketAliasInit(void); 7674778Sbrianvoid PacketAliasSetAddress(struct in_addr _addr); 7774778Sbrianvoid PacketAliasSetFWBase(unsigned int _base, unsigned int _num); 78120372Smarcusvoid PacketAliasSetSkinnyPort(unsigned int _port); 7974778Sbrianunsigned int 8074778Sbrian PacketAliasSetMode(unsigned int _flags, unsigned int _mask); 8174778Sbrianvoid PacketAliasUninit(void); 8227864Sbrian 8374778Sbrian/* Packet Handling functions. */ 8474778Sbrianint PacketAliasIn(char *_ptr, int _maxpacketsize); 8574778Sbrianint PacketAliasOut(char *_ptr, int _maxpacketsize); 8674778Sbrianint PacketUnaliasOut(char *_ptr, int _maxpacketsize); 8727864Sbrian 8874778Sbrian/* Port and address redirection functions. */ 8932377Seivind 9027864Sbrian 9174778Sbrianint PacketAliasAddServer(struct alias_link *_link, 9274778Sbrian struct in_addr _addr, unsigned short _port); 9374778Sbrianstruct alias_link * 9474778Sbrian PacketAliasRedirectAddr(struct in_addr _src_addr, 9574778Sbrian struct in_addr _alias_addr); 96115650Sruint PacketAliasRedirectDynamic(struct alias_link *_link); 9774778Sbrianvoid PacketAliasRedirectDelete(struct alias_link *_link); 9874778Sbrianstruct alias_link * 9974778Sbrian PacketAliasRedirectPort(struct in_addr _src_addr, 10074778Sbrian unsigned short _src_port, struct in_addr _dst_addr, 10174778Sbrian unsigned short _dst_port, struct in_addr _alias_addr, 10274778Sbrian unsigned short _alias_port, unsigned char _proto); 10374778Sbrianstruct alias_link * 10474778Sbrian PacketAliasRedirectProto(struct in_addr _src_addr, 10574778Sbrian struct in_addr _dst_addr, struct in_addr _alias_addr, 10674778Sbrian unsigned char _proto); 10727864Sbrian 10874778Sbrian/* Fragment Handling functions. */ 10974778Sbrianvoid PacketAliasFragmentIn(char *_ptr, char *_ptr_fragment); 11074778Sbrianchar *PacketAliasGetFragment(char *_ptr); 11174778Sbrianint PacketAliasSaveFragment(char *_ptr); 11232377Seivind 11374778Sbrian/* Miscellaneous functions. */ 11474778Sbrianint PacketAliasCheckNewLink(void); 11574778Sbrianunsigned short 11674778Sbrian PacketAliasInternetChecksum(unsigned short *_ptr, int _nbytes); 11774778Sbrianvoid PacketAliasSetTarget(struct in_addr _target_addr); 11827864Sbrian 11974778Sbrian/* Transparent proxying routines. */ 12074778Sbrianint PacketAliasProxyRule(const char *_cmd); 12127864Sbrian 122124621Sphk/* NEW API */ 123124621Sphk 124124621Sphk/* Initialization and control functions. */ 125124621Sphkstruct libalias *LibAliasInit(struct libalias *); 126124621Sphkvoid LibAliasSetAddress(struct libalias *, struct in_addr _addr); 127124621Sphkvoid LibAliasSetFWBase(struct libalias *, unsigned int _base, unsigned int _num); 128124621Sphkvoid LibAliasSetSkinnyPort(struct libalias *, unsigned int _port); 129124621Sphkunsigned int 130124621Sphk LibAliasSetMode(struct libalias *, unsigned int _flags, unsigned int _mask); 131124621Sphkvoid LibAliasUninit(struct libalias *); 132124621Sphk 133124621Sphk/* Packet Handling functions. */ 134124621Sphkint LibAliasIn(struct libalias *, char *_ptr, int _maxpacketsize); 135124621Sphkint LibAliasOut(struct libalias *, char *_ptr, int _maxpacketsize); 136124621Sphkint LibAliasUnaliasOut(struct libalias *, char *_ptr, int _maxpacketsize); 137124621Sphk 138124621Sphk/* Port and address redirection functions. */ 139124621Sphk 140124621Sphkint LibAliasAddServer(struct libalias *, struct alias_link *_link, 141124621Sphk struct in_addr _addr, unsigned short _port); 142124621Sphkstruct alias_link * 143124621Sphk LibAliasRedirectAddr(struct libalias *, struct in_addr _src_addr, 144124621Sphk struct in_addr _alias_addr); 145124621Sphkint LibAliasRedirectDynamic(struct libalias *, struct alias_link *_link); 146124621Sphkvoid LibAliasRedirectDelete(struct libalias *, struct alias_link *_link); 147124621Sphkstruct alias_link * 148124621Sphk LibAliasRedirectPort(struct libalias *, struct in_addr _src_addr, 149124621Sphk unsigned short _src_port, struct in_addr _dst_addr, 150124621Sphk unsigned short _dst_port, struct in_addr _alias_addr, 151124621Sphk unsigned short _alias_port, unsigned char _proto); 152124621Sphkstruct alias_link * 153124621Sphk LibAliasRedirectProto(struct libalias *, struct in_addr _src_addr, 154124621Sphk struct in_addr _dst_addr, struct in_addr _alias_addr, 155124621Sphk unsigned char _proto); 156124621Sphk 157124621Sphk/* Fragment Handling functions. */ 158124621Sphkvoid LibAliasFragmentIn(struct libalias *, char *_ptr, char *_ptr_fragment); 159124621Sphkchar *LibAliasGetFragment(struct libalias *, char *_ptr); 160124621Sphkint LibAliasSaveFragment(struct libalias *, char *_ptr); 161124621Sphk 162124621Sphk/* Miscellaneous functions. */ 163124621Sphkint LibAliasCheckNewLink(struct libalias *); 164124621Sphkunsigned short 165124621Sphk LibAliasInternetChecksum(struct libalias *, unsigned short *_ptr, int _nbytes); 166124621Sphkvoid LibAliasSetTarget(struct libalias *, struct in_addr _target_addr); 167124621Sphk 168124621Sphk/* Transparent proxying routines. */ 169124621Sphkint LibAliasProxyRule(struct libalias *, const char *_cmd); 170124621Sphk 171124621Sphk 172124621Sphk/* 173124621Sphk * Mode flags and other constants. 174124621Sphk */ 175124621Sphk 176124621Sphk 17774778Sbrian/* Mode flags, set using PacketAliasSetMode() */ 17863899Sarchie 17974778Sbrian/* 18074778Sbrian * If PKT_ALIAS_LOG is set, a message will be printed to /var/log/alias.log 18174778Sbrian * every time a link is created or deleted. This is useful for debugging. 18274778Sbrian */ 18374778Sbrian#define PKT_ALIAS_LOG 0x01 18427864Sbrian 18574778Sbrian/* 18674778Sbrian * If PKT_ALIAS_DENY_INCOMING is set, then incoming connections (e.g. to ftp, 18774778Sbrian * telnet or web servers will be prevented by the aliasing mechanism. 18874778Sbrian */ 18974778Sbrian#define PKT_ALIAS_DENY_INCOMING 0x02 19059702Sru 19174778Sbrian/* 19274778Sbrian * If PKT_ALIAS_SAME_PORTS is set, packets will be attempted sent from the 19374778Sbrian * same port as they originated on. This allows e.g. rsh to work *99% of the 19474778Sbrian * time*, but _not_ 100% (it will be slightly flakey instead of not working 19574778Sbrian * at all). This mode bit is set by PacketAliasInit(), so it is a default 19674778Sbrian * mode of operation. 19774778Sbrian */ 19874778Sbrian#define PKT_ALIAS_SAME_PORTS 0x04 19944307Sbrian 20074778Sbrian/* 20174778Sbrian * If PKT_ALIAS_USE_SOCKETS is set, then when partially specified links (e.g. 20274778Sbrian * destination port and/or address is zero), the packet aliasing engine will 20374778Sbrian * attempt to allocate a socket for the aliasing port it chooses. This will 20474778Sbrian * avoid interference with the host machine. Fully specified links do not 20574778Sbrian * require this. This bit is set after a call to PacketAliasInit(), so it is 20674778Sbrian * a default mode of operation. 20774778Sbrian */ 20874778Sbrian#define PKT_ALIAS_USE_SOCKETS 0x08 20927864Sbrian 21074778Sbrian/*- 21174778Sbrian * If PKT_ALIAS_UNREGISTERED_ONLY is set, then only packets with 21274778Sbrian * unregistered source addresses will be aliased. Private 21374778Sbrian * addresses are those in the following ranges: 21474778Sbrian * 21574778Sbrian * 10.0.0.0 -> 10.255.255.255 21674778Sbrian * 172.16.0.0 -> 172.31.255.255 21774778Sbrian * 192.168.0.0 -> 192.168.255.255 21874778Sbrian */ 21974778Sbrian#define PKT_ALIAS_UNREGISTERED_ONLY 0x10 22027864Sbrian 22174778Sbrian/* 22274778Sbrian * If PKT_ALIAS_RESET_ON_ADDR_CHANGE is set, then the table of dynamic 22374778Sbrian * aliasing links will be reset whenever PacketAliasSetAddress() changes the 22474778Sbrian * default aliasing address. If the default aliasing address is left 22574778Sbrian * unchanged by this function call, then the table of dynamic aliasing links 22674778Sbrian * will be left intact. This bit is set after a call to PacketAliasInit(). 22774778Sbrian */ 22874778Sbrian#define PKT_ALIAS_RESET_ON_ADDR_CHANGE 0x20 22927864Sbrian 23035314Sbrian#ifndef NO_FW_PUNCH 23174778Sbrian/* 23274778Sbrian * If PKT_ALIAS_PUNCH_FW is set, active FTP and IRC DCC connections will 23374778Sbrian * create a 'hole' in the firewall to allow the transfers to work. The 23474778Sbrian * ipfw rule number that the hole is created with is controlled by 23574778Sbrian * PacketAliasSetFWBase(). The hole will be attached to that 23674778Sbrian * particular alias_link, so when the link goes away the hole is deleted. 23774778Sbrian */ 23874778Sbrian#define PKT_ALIAS_PUNCH_FW 0x100 23935314Sbrian#endif 24032377Seivind 24174778Sbrian/* 24274778Sbrian * If PKT_ALIAS_PROXY_ONLY is set, then NAT will be disabled and only 24374778Sbrian * transparent proxying is performed. 24474778Sbrian */ 24574778Sbrian#define PKT_ALIAS_PROXY_ONLY 0x40 24644307Sbrian 24774778Sbrian/* 24874778Sbrian * If PKT_ALIAS_REVERSE is set, the actions of PacketAliasIn() and 24974778Sbrian * PacketAliasOut() are reversed. 25074778Sbrian */ 25174778Sbrian#define PKT_ALIAS_REVERSE 0x80 25244307Sbrian 25374778Sbrian/* Function return codes. */ 25474778Sbrian#define PKT_ALIAS_ERROR -1 25574778Sbrian#define PKT_ALIAS_OK 1 25674778Sbrian#define PKT_ALIAS_IGNORED 2 25774778Sbrian#define PKT_ALIAS_UNRESOLVED_FRAGMENT 3 25874778Sbrian#define PKT_ALIAS_FOUND_HEADER_FRAGMENT 4 25926026Sbrian 26074778Sbrian#endif /* !_ALIAS_H_ */ 26174778Sbrian 26274778Sbrian/* lint -restore */ 263