/*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. */ #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 PacketAliasSetAddress(struct in_addr); extern unsigned int PacketAliasSetMode(unsigned int, unsigned int); /* 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 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 u_short PacketAliasInternetChecksum(u_short *, int); /* In version 2.2, the function names were rationalized to all be of the form PacketAlias... These are the old function names for backwards compatibility */ extern int SaveFragmentPtr(char *); extern char *GetNextFragmentPtr(char *); extern void FragmentAliasIn(char *, char *); extern void SetPacketAliasAddress(struct in_addr); extern void InitPacketAlias(void); extern unsigned int SetPacketAliasMode(unsigned int, unsigned int); extern int PacketAliasIn2(char *, struct in_addr, int maxpacketsize); extern int PacketAliasOut2(char *, struct in_addr, int maxpacketsize); extern int PacketAliasPermanentLink(struct in_addr, u_short, struct in_addr, u_short, u_short, u_char); extern u_short InternetChecksum(u_short *, int); /* Obsolete constant */ #define PKT_ALIAS_NEW_LINK 5 /********************** 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 /* 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 #undef __libalias_version #define __libalias_version "2.4" #endif /*lint -restore */