xref: /freebsd/sys/netinet/libalias/alias.h (revision 81a654646e9e9f6052730504dfee28be8532c94e)
13b160b8bSBrian Somers /* lint -save -library Flexelint comment for external headers */
23b160b8bSBrian Somers 
371593f95SBrian Somers /*-
4e83aaae3SBrian Somers  * Copyright (c) 2001 Charles Mott <cm@linktel.net>
5f987e1bdSBrian Somers  * All rights reserved.
6f987e1bdSBrian Somers  *
7f987e1bdSBrian Somers  * Redistribution and use in source and binary forms, with or without
8f987e1bdSBrian Somers  * modification, are permitted provided that the following conditions
9f987e1bdSBrian Somers  * are met:
10f987e1bdSBrian Somers  * 1. Redistributions of source code must retain the above copyright
11f987e1bdSBrian Somers  *    notice, this list of conditions and the following disclaimer.
12f987e1bdSBrian Somers  * 2. Redistributions in binary form must reproduce the above copyright
13f987e1bdSBrian Somers  *    notice, this list of conditions and the following disclaimer in the
14f987e1bdSBrian Somers  *    documentation and/or other materials provided with the distribution.
15f987e1bdSBrian Somers  *
16f987e1bdSBrian Somers  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17f987e1bdSBrian Somers  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18f987e1bdSBrian Somers  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19f987e1bdSBrian Somers  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20f987e1bdSBrian Somers  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21f987e1bdSBrian Somers  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22f987e1bdSBrian Somers  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23f987e1bdSBrian Somers  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24f987e1bdSBrian Somers  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25f987e1bdSBrian Somers  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26f987e1bdSBrian Somers  * SUCH DAMAGE.
27f987e1bdSBrian Somers  *
28f987e1bdSBrian Somers  * $FreeBSD$
29f987e1bdSBrian Somers  */
30f987e1bdSBrian Somers 
31be4f3cd0SPaolo Pisati /*
3271593f95SBrian Somers  * Alias.h defines the outside world interfaces for the packet aliasing
3371593f95SBrian Somers  * software.
3471593f95SBrian Somers  *
3571593f95SBrian Somers  * This software is placed into the public domain with no restrictions on its
3671593f95SBrian Somers  * distribution.
373b160b8bSBrian Somers  */
383b160b8bSBrian Somers 
393b160b8bSBrian Somers #ifndef _ALIAS_H_
403b160b8bSBrian Somers #define	_ALIAS_H_
413b160b8bSBrian Somers 
42be4f3cd0SPaolo Pisati #include <netinet/in_systm.h>
43be4f3cd0SPaolo Pisati #include <netinet/in.h>
44be4f3cd0SPaolo Pisati #include <netinet/ip.h>
45be4f3cd0SPaolo Pisati 
46be4f3cd0SPaolo Pisati #define LIBALIAS_BUF_SIZE 128
47f87fe393SGleb Smirnoff #ifdef	_KERNEL
48f87fe393SGleb Smirnoff /*
49f87fe393SGleb Smirnoff  * The kernel version of libalias does not support these features.
50f87fe393SGleb Smirnoff  */
51f87fe393SGleb Smirnoff #define	NO_FW_PUNCH
52f87fe393SGleb Smirnoff #define	NO_USE_SOCKETS
53f87fe393SGleb Smirnoff #endif
54f87fe393SGleb Smirnoff 
555e289f9eSPoul-Henning Kamp /*
565e289f9eSPoul-Henning Kamp  * The external interface to libalias, the packet aliasing engine.
575e289f9eSPoul-Henning Kamp  *
585e289f9eSPoul-Henning Kamp  * There are two sets of functions:
595e289f9eSPoul-Henning Kamp  *
605e289f9eSPoul-Henning Kamp  * PacketAlias*() the old API which doesn't take an instance pointer
615e289f9eSPoul-Henning Kamp  * and therefore can only have one packet engine at a time.
625e289f9eSPoul-Henning Kamp  *
635e289f9eSPoul-Henning Kamp  * LibAlias*() the new API which takes as first argument a pointer to
645e289f9eSPoul-Henning Kamp  * the instance of the packet aliasing engine.
655e289f9eSPoul-Henning Kamp  *
665e289f9eSPoul-Henning Kamp  * The functions otherwise correspond to each other one for one, except
675e289f9eSPoul-Henning Kamp  * for the LibAliasUnaliasOut()/PacketUnaliasOut() function which were
685e289f9eSPoul-Henning Kamp  * were misnamed in the old API.
695e289f9eSPoul-Henning Kamp  */
705e289f9eSPoul-Henning Kamp 
715e289f9eSPoul-Henning Kamp /*
725e289f9eSPoul-Henning Kamp  * The instance structure
735e289f9eSPoul-Henning Kamp  */
745e289f9eSPoul-Henning Kamp struct libalias;
755e289f9eSPoul-Henning Kamp 
765e289f9eSPoul-Henning Kamp /*
775e289f9eSPoul-Henning Kamp  * An anonymous structure, a pointer to which is returned from
785e289f9eSPoul-Henning Kamp  * PacketAliasRedirectAddr(), PacketAliasRedirectPort() or
795e289f9eSPoul-Henning Kamp  * PacketAliasRedirectProto(), passed to PacketAliasAddServer(),
805e289f9eSPoul-Henning Kamp  * and freed by PacketAliasRedirectDelete().
815e289f9eSPoul-Henning Kamp  */
825e289f9eSPoul-Henning Kamp struct alias_link;
835e289f9eSPoul-Henning Kamp 
845e289f9eSPoul-Henning Kamp /* Initialization and control functions. */
855e289f9eSPoul-Henning Kamp struct libalias *LibAliasInit(struct libalias *);
865e289f9eSPoul-Henning Kamp void		LibAliasSetAddress(struct libalias *, struct in_addr _addr);
875e289f9eSPoul-Henning Kamp void		LibAliasSetFWBase(struct libalias *, unsigned int _base, unsigned int _num);
885e289f9eSPoul-Henning Kamp void		LibAliasSetSkinnyPort(struct libalias *, unsigned int _port);
895e289f9eSPoul-Henning Kamp unsigned int
905e289f9eSPoul-Henning Kamp 		LibAliasSetMode(struct libalias *, unsigned int _flags, unsigned int _mask);
915e289f9eSPoul-Henning Kamp void		LibAliasUninit(struct libalias *);
925e289f9eSPoul-Henning Kamp 
935e289f9eSPoul-Henning Kamp /* Packet Handling functions. */
945e289f9eSPoul-Henning Kamp int		LibAliasIn (struct libalias *, char *_ptr, int _maxpacketsize);
955e289f9eSPoul-Henning Kamp int		LibAliasOut(struct libalias *, char *_ptr, int _maxpacketsize);
96e6bbb691SPoul-Henning Kamp int		LibAliasOutTry(struct libalias *, char *_ptr, int _maxpacketsize, int _create);
975e289f9eSPoul-Henning Kamp int		LibAliasUnaliasOut(struct libalias *, char *_ptr, int _maxpacketsize);
985e289f9eSPoul-Henning Kamp 
995e289f9eSPoul-Henning Kamp /* Port and address redirection functions. */
1005e289f9eSPoul-Henning Kamp 
101f0f93429SDag-Erling Smørgrav int
102ed01a582SDag-Erling Smørgrav LibAliasAddServer(struct libalias *, struct alias_link *_lnk,
1035e289f9eSPoul-Henning Kamp     struct in_addr _addr, unsigned short _port);
1045e289f9eSPoul-Henning Kamp struct alias_link *
1055e289f9eSPoul-Henning Kamp LibAliasRedirectAddr(struct libalias *, struct in_addr _src_addr,
1065e289f9eSPoul-Henning Kamp     struct in_addr _alias_addr);
107ed01a582SDag-Erling Smørgrav int		LibAliasRedirectDynamic(struct libalias *, struct alias_link *_lnk);
108ed01a582SDag-Erling Smørgrav void		LibAliasRedirectDelete(struct libalias *, struct alias_link *_lnk);
1095e289f9eSPoul-Henning Kamp struct alias_link *
1105e289f9eSPoul-Henning Kamp LibAliasRedirectPort(struct libalias *, struct in_addr _src_addr,
1115e289f9eSPoul-Henning Kamp     unsigned short _src_port, struct in_addr _dst_addr,
1125e289f9eSPoul-Henning Kamp     unsigned short _dst_port, struct in_addr _alias_addr,
1135e289f9eSPoul-Henning Kamp     unsigned short _alias_port, unsigned char _proto);
1145e289f9eSPoul-Henning Kamp struct alias_link *
1155e289f9eSPoul-Henning Kamp LibAliasRedirectProto(struct libalias *, struct in_addr _src_addr,
1165e289f9eSPoul-Henning Kamp     struct in_addr _dst_addr, struct in_addr _alias_addr,
1175e289f9eSPoul-Henning Kamp     unsigned char _proto);
1185e289f9eSPoul-Henning Kamp 
1195e289f9eSPoul-Henning Kamp /* Fragment Handling functions. */
1205e289f9eSPoul-Henning Kamp void		LibAliasFragmentIn(struct libalias *, char *_ptr, char *_ptr_fragment);
1215e289f9eSPoul-Henning Kamp char           *LibAliasGetFragment(struct libalias *, char *_ptr);
1225e289f9eSPoul-Henning Kamp int		LibAliasSaveFragment(struct libalias *, char *_ptr);
1235e289f9eSPoul-Henning Kamp 
1245e289f9eSPoul-Henning Kamp /* Miscellaneous functions. */
1255e289f9eSPoul-Henning Kamp int		LibAliasCheckNewLink(struct libalias *);
1265e289f9eSPoul-Henning Kamp unsigned short
1275e289f9eSPoul-Henning Kamp 		LibAliasInternetChecksum(struct libalias *, unsigned short *_ptr, int _nbytes);
1285e289f9eSPoul-Henning Kamp void		LibAliasSetTarget(struct libalias *, struct in_addr _target_addr);
1295e289f9eSPoul-Henning Kamp 
1305e289f9eSPoul-Henning Kamp /* Transparent proxying routines. */
1315e289f9eSPoul-Henning Kamp int		LibAliasProxyRule(struct libalias *, const char *_cmd);
1325e289f9eSPoul-Henning Kamp 
133be4f3cd0SPaolo Pisati /* Module handling API */
134be4f3cd0SPaolo Pisati int             LibAliasLoadModule(char *);
135be4f3cd0SPaolo Pisati int             LibAliasUnLoadAllModule(void);
136be4f3cd0SPaolo Pisati int             LibAliasRefreshModules(void);
1375e289f9eSPoul-Henning Kamp 
138e876228eSPaolo Pisati /* Mbuf helper function. */
139e876228eSPaolo Pisati struct mbuf    *m_megapullup(struct mbuf *, int);
140e876228eSPaolo Pisati 
1415e289f9eSPoul-Henning Kamp /*
1425e289f9eSPoul-Henning Kamp  * Mode flags and other constants.
1435e289f9eSPoul-Henning Kamp  */
1445e289f9eSPoul-Henning Kamp 
1455e289f9eSPoul-Henning Kamp 
14671593f95SBrian Somers /* Mode flags, set using PacketAliasSetMode() */
1473efa11bbSBrian Somers 
14871593f95SBrian Somers /*
14971593f95SBrian Somers  * If PKT_ALIAS_LOG is set, a message will be printed to /var/log/alias.log
15071593f95SBrian Somers  * every time a link is created or deleted.  This is useful for debugging.
15171593f95SBrian Somers  */
1523efa11bbSBrian Somers #define	PKT_ALIAS_LOG			0x01
1533b160b8bSBrian Somers 
15471593f95SBrian Somers /*
15571593f95SBrian Somers  * If PKT_ALIAS_DENY_INCOMING is set, then incoming connections (e.g. to ftp,
15671593f95SBrian Somers  * telnet or web servers will be prevented by the aliasing mechanism.
15771593f95SBrian Somers  */
1583efa11bbSBrian Somers #define	PKT_ALIAS_DENY_INCOMING		0x02
1593b160b8bSBrian Somers 
16071593f95SBrian Somers /*
16171593f95SBrian Somers  * If PKT_ALIAS_SAME_PORTS is set, packets will be attempted sent from the
16271593f95SBrian Somers  * same port as they originated on.  This allows e.g. rsh to work *99% of the
16371593f95SBrian Somers  * time*, but _not_ 100% (it will be slightly flakey instead of not working
16471593f95SBrian Somers  * at all).  This mode bit is set by PacketAliasInit(), so it is a default
16571593f95SBrian Somers  * mode of operation.
16671593f95SBrian Somers  */
1673efa11bbSBrian Somers #define	PKT_ALIAS_SAME_PORTS		0x04
1683b160b8bSBrian Somers 
16971593f95SBrian Somers /*
17071593f95SBrian Somers  * If PKT_ALIAS_USE_SOCKETS is set, then when partially specified links (e.g.
17171593f95SBrian Somers  * destination port and/or address is zero), the packet aliasing engine will
17271593f95SBrian Somers  * attempt to allocate a socket for the aliasing port it chooses.  This will
17371593f95SBrian Somers  * avoid interference with the host machine.  Fully specified links do not
17471593f95SBrian Somers  * require this.  This bit is set after a call to PacketAliasInit(), so it is
17571593f95SBrian Somers  * a default mode of operation.
17671593f95SBrian Somers  */
17700fc9a5bSGleb Smirnoff #ifndef	NO_USE_SOCKETS
1783efa11bbSBrian Somers #define	PKT_ALIAS_USE_SOCKETS		0x08
17900fc9a5bSGleb Smirnoff #endif
18071593f95SBrian Somers /*-
18171593f95SBrian Somers  * If PKT_ALIAS_UNREGISTERED_ONLY is set, then only packets with
18271593f95SBrian Somers  * unregistered source addresses will be aliased.  Private
18371593f95SBrian Somers  * addresses are those in the following ranges:
18471593f95SBrian Somers  *
18571593f95SBrian Somers  *		10.0.0.0     ->   10.255.255.255
18671593f95SBrian Somers  *		172.16.0.0   ->   172.31.255.255
18771593f95SBrian Somers  *		192.168.0.0  ->   192.168.255.255
18871593f95SBrian Somers  */
1893efa11bbSBrian Somers #define	PKT_ALIAS_UNREGISTERED_ONLY	0x10
1903b160b8bSBrian Somers 
19171593f95SBrian Somers /*
19271593f95SBrian Somers  * If PKT_ALIAS_RESET_ON_ADDR_CHANGE is set, then the table of dynamic
19371593f95SBrian Somers  * aliasing links will be reset whenever PacketAliasSetAddress() changes the
19471593f95SBrian Somers  * default aliasing address.  If the default aliasing address is left
19571593f95SBrian Somers  * unchanged by this function call, then the table of dynamic aliasing links
19671593f95SBrian Somers  * will be left intact.  This bit is set after a call to PacketAliasInit().
19771593f95SBrian Somers  */
1983efa11bbSBrian Somers #define	PKT_ALIAS_RESET_ON_ADDR_CHANGE	0x20
1993b160b8bSBrian Somers 
20071593f95SBrian Somers /*
20171593f95SBrian Somers  * If PKT_ALIAS_PROXY_ONLY is set, then NAT will be disabled and only
20271593f95SBrian Somers  * transparent proxying is performed.
20371593f95SBrian Somers  */
2047d96f4efSBrian Somers #define	PKT_ALIAS_PROXY_ONLY		0x40
2057d96f4efSBrian Somers 
20671593f95SBrian Somers /*
20771593f95SBrian Somers  * If PKT_ALIAS_REVERSE is set, the actions of PacketAliasIn() and
20871593f95SBrian Somers  * PacketAliasOut() are reversed.
20971593f95SBrian Somers  */
2107d96f4efSBrian Somers #define	PKT_ALIAS_REVERSE		0x80
2117d96f4efSBrian Somers 
212*81a65464SAndrey V. Elsukov #ifndef NO_FW_PUNCH
213*81a65464SAndrey V. Elsukov /*
214*81a65464SAndrey V. Elsukov  * If PKT_ALIAS_PUNCH_FW is set, active FTP and IRC DCC connections will
215*81a65464SAndrey V. Elsukov  * create a 'hole' in the firewall to allow the transfers to work.  The
216*81a65464SAndrey V. Elsukov  * ipfw rule number that the hole is created with is controlled by
217*81a65464SAndrey V. Elsukov  * PacketAliasSetFWBase().  The hole will be attached to that
218*81a65464SAndrey V. Elsukov  * particular alias_link, so when the link goes away the hole is deleted.
219*81a65464SAndrey V. Elsukov  */
220*81a65464SAndrey V. Elsukov #define	PKT_ALIAS_PUNCH_FW		0x100
221*81a65464SAndrey V. Elsukov #endif
222*81a65464SAndrey V. Elsukov 
22371593f95SBrian Somers /* Function return codes. */
2243b160b8bSBrian Somers #define	PKT_ALIAS_ERROR			-1
2253b160b8bSBrian Somers #define	PKT_ALIAS_OK			1
2263b160b8bSBrian Somers #define	PKT_ALIAS_IGNORED		2
2273b160b8bSBrian Somers #define	PKT_ALIAS_UNRESOLVED_FRAGMENT	3
2283b160b8bSBrian Somers #define	PKT_ALIAS_FOUND_HEADER_FRAGMENT	4
2293b160b8bSBrian Somers 
23071593f95SBrian Somers #endif				/* !_ALIAS_H_ */
23171593f95SBrian Somers 
2323b160b8bSBrian Somers /* lint -restore */
233