/*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. $Id: alias.h,v 1.1.1.1 2000/01/11 01:48:42 wsanchez Exp $ */ #ifndef _ALIAS_H_ #define _ALIAS_H_ #ifndef NULL #define NULL 0 #endif /* 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 PacketAliasPptp(struct in_addr); 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 SetPacketAliasMode() */ /* 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 eg 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 with unregistered source addresses will be aliased (along with those of the ppp host maching itself. 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 functions 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 0x40 #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 */