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/*lint -save -library Flexelint comment for external headers */
/*
Alias.h defines the outside world interfaces for the packet
aliasing software.
This software is placed into the public domain with no restrictions
on its distribution.
$FreeBSD$
*/
#ifndef _ALIAS_H_
#define _ALIAS_H_
/* Alias link representative (incomplete struct) */
struct alias_link;
/* External interfaces (API) to packet aliasing engine */
/* Initialization and Control */
extern void
PacketAliasInit(void);
extern void
PacketAliasUninit(void);
extern void
PacketAliasSetAddress(struct in_addr);
extern unsigned int
PacketAliasSetMode(unsigned int, unsigned int);
#ifndef NO_FW_PUNCH
extern void
PacketAliasSetFWBase(unsigned int, unsigned int);
#endif
/* Packet Handling */
extern int
PacketAliasIn(char *, int maxpacketsize);
extern int
PacketAliasOut(char *, int maxpacketsize);
/* Port and Address Redirection */
extern struct alias_link *
PacketAliasRedirectPort(struct in_addr, u_short,
struct in_addr, u_short,
struct in_addr, u_short,
u_char);
extern int
PacketAliasAddServer(struct alias_link *link,
struct in_addr addr,
u_short port);
extern struct alias_link *
PacketAliasRedirectProto(struct in_addr,
struct in_addr,
struct in_addr,
u_char);
extern struct alias_link *
PacketAliasRedirectAddr(struct in_addr,
struct in_addr);
extern void
PacketAliasRedirectDelete(struct alias_link *);
/* Fragment Handling */
extern int
PacketAliasSaveFragment(char *);
extern char *
PacketAliasGetFragment(char *);
extern void
PacketAliasFragmentIn(char *, char *);
/* Miscellaneous Functions */
extern void
PacketAliasSetTarget(struct in_addr addr);
extern int
PacketAliasCheckNewLink(void);
extern u_short
PacketAliasInternetChecksum(u_short *, int);
/* Transparent Proxying */
extern int
PacketAliasProxyRule(const char *);
/********************** Mode flags ********************/
/* Set these flags using PacketAliasSetMode() */
/* If PKT_ALIAS_LOG is set, a message will be printed to
/var/log/alias.log every time a link is created or deleted. This
is useful for debugging */
#define PKT_ALIAS_LOG 0x01
/* If PKT_ALIAS_DENY_INCOMING is set, then incoming connections (e.g.
to ftp, telnet or web servers will be prevented by the aliasing
mechanism. */
#define PKT_ALIAS_DENY_INCOMING 0x02
/* If PKT_ALIAS_SAME_PORTS is set, packets will be attempted sent from
the same port as they originated on. This allows e.g. rsh to work
*99% of the time*, but _not_ 100%. (It will be slightly flakey
instead of not working at all.) This mode bit is set by
PacketAliasInit(), so it is a default mode of operation. */
#define PKT_ALIAS_SAME_PORTS 0x04
/* If PKT_ALIAS_USE_SOCKETS is set, then when partially specified
links (e.g. destination port and/or address is zero), the packet
aliasing engine will attempt to allocate a socket for the aliasing
port it chooses. This will avoid interference with the host
machine. Fully specified links do not require this. This bit
is set after a call to PacketAliasInit(), so it is a default
mode of operation. */
#define PKT_ALIAS_USE_SOCKETS 0x08
/* If PKT_ALIAS_UNREGISTERED_ONLY is set, then only packets with
unregistered source addresses will be aliased. Private
addresses are those in the following ranges:
10.0.0.0 -> 10.255.255.255
172.16.0.0 -> 172.31.255.255
192.168.0.0 -> 192.168.255.255 */
#define PKT_ALIAS_UNREGISTERED_ONLY 0x10
/* If PKT_ALIAS_RESET_ON_ADDR_CHANGE is set, then the table of dynamic
aliasing links will be reset whenever PacketAliasSetAddress()
changes the default aliasing address. If the default aliasing
address is left unchanged by this function call, then the
table of dynamic aliasing links will be left intact. This
bit is set after a call to PacketAliasInit(). */
#define PKT_ALIAS_RESET_ON_ADDR_CHANGE 0x20
#ifndef NO_FW_PUNCH
/* If PKT_ALIAS_PUNCH_FW is set, active FTP and IRC DCC connections
will create a 'hole' in the firewall to allow the transfers to
work. Where (IPFW "line-numbers") the hole is created is
controlled by PacketAliasSetFWBase(base, size). The hole will be
attached to that particular alias_link, so when the link goes away
so do the hole. */
#define PKT_ALIAS_PUNCH_FW 0x100
#endif
/* If PKT_ALIAS_PROXY_ONLY is set, then NAT will be disabled and only
transparent proxying performed */
#define PKT_ALIAS_PROXY_ONLY 0x40
/* If PKT_ALIAS_REVERSE is set, the actions of PacketAliasIn()
and PacketAliasOut() are reversed */
#define PKT_ALIAS_REVERSE 0x80
/* Return Codes */
#define PKT_ALIAS_ERROR -1
#define PKT_ALIAS_OK 1
#define PKT_ALIAS_IGNORED 2
#define PKT_ALIAS_UNRESOLVED_FRAGMENT 3
#define PKT_ALIAS_FOUND_HEADER_FRAGMENT 4
#endif
/*lint -restore */
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