1 /*lint -save -library Flexelint comment for external headers */ 2 3 /* 4 Alias.h defines the outside world interfaces for the packet 5 aliasing software. 6 7 This software is placed into the public domain with no restrictions 8 on its distribution. 9 */ 10 11 12 #ifndef _ALIAS_H_ 13 #define _ALIAS_H_ 14 15 #ifndef NULL 16 #define NULL 0 17 #endif 18 19 /* Alias link representative (incomplete struct) */ 20 struct alias_link; 21 22 /* External interfaces (API) to packet aliasing engine */ 23 24 /* Initialization and Control */ 25 extern void 26 PacketAliasInit(void); 27 28 extern void 29 PacketAliasSetAddress(struct in_addr); 30 31 extern unsigned int 32 PacketAliasSetMode(unsigned int, unsigned int); 33 34 /* Packet Handling */ 35 extern int 36 PacketAliasIn(char *, int maxpacketsize); 37 38 extern int 39 PacketAliasOut(char *, int maxpacketsize); 40 41 /* Port and Address Redirection */ 42 extern struct alias_link * 43 PacketAliasRedirectPort(struct in_addr, u_short, 44 struct in_addr, u_short, 45 struct in_addr, u_short, 46 u_char); 47 48 extern struct alias_link * 49 PacketAliasRedirectAddr(struct in_addr, 50 struct in_addr); 51 52 extern void 53 PacketAliasRedirectDelete(struct alias_link *); 54 55 /* Fragment Handling */ 56 extern int 57 PacketAliasSaveFragment(char *); 58 59 extern char * 60 PacketAliasGetFragment(char *); 61 62 extern void 63 PacketAliasFragmentIn(char *, char *); 64 65 /* Miscellaneous Functions */ 66 extern u_short 67 PacketAliasInternetChecksum(u_short *, int); 68 69 70 /* 71 In version 2.2, the function names were rationalized 72 to all be of the form PacketAlias... These are the 73 old function names for backwards compatibility 74 */ 75 extern int SaveFragmentPtr(char *); 76 extern char *GetNextFragmentPtr(char *); 77 extern void FragmentAliasIn(char *, char *); 78 extern void SetPacketAliasAddress(struct in_addr); 79 extern void InitPacketAlias(void); 80 extern unsigned int SetPacketAliasMode(unsigned int, unsigned int); 81 extern int PacketAliasIn2(char *, struct in_addr, int maxpacketsize); 82 extern int PacketAliasOut2(char *, struct in_addr, int maxpacketsize); 83 extern int 84 PacketAliasPermanentLink(struct in_addr, u_short, 85 struct in_addr, u_short, 86 u_short, u_char); 87 extern u_short InternetChecksum(u_short *, int); 88 89 /* Obsolete constant */ 90 #define PKT_ALIAS_NEW_LINK 5 91 92 /********************** Mode flags ********************/ 93 /* Set these flags using SetPacketAliasMode() */ 94 95 /* If PKT_ALIAS_LOG is set, a message will be printed to 96 /var/log/alias.log every time a link is created or deleted. This 97 is useful for debugging */ 98 #define PKT_ALIAS_LOG 0x01 99 100 /* If PKT_ALIAS_DENY_INCOMING is set, then incoming connections (e.g. 101 to ftp, telnet or web servers will be prevented by the aliasing 102 mechanism. */ 103 #define PKT_ALIAS_DENY_INCOMING 0x02 104 105 /* If PKT_ALIAS_SAME_PORTS is set, packets will be attempted sent from 106 the same port as they originated on. This allows eg rsh to work 107 *99% of the time*, but _not_ 100%. (It will be slightly flakey 108 instead of not working at all.) This mode bit is set by 109 PacketAliasInit(), so it is a default mode of operation. */ 110 #define PKT_ALIAS_SAME_PORTS 0x04 111 112 /* If PKT_ALIAS_USE_SOCKETS is set, then when partially specified 113 links (e.g. destination port and/or address is zero), the packet 114 aliasing engine will attempt to allocate a socket for the aliasing 115 port it chooses. This will avoid interference with the host 116 machine. Fully specified links do not require this. This bit 117 is set after a call to PacketAliasInit(), so it is a default 118 mode of operation.*/ 119 #define PKT_ALIAS_USE_SOCKETS 0x08 120 121 /* If PKT_ALIAS_UNREGISTERED_ONLY is set, then only packets with with 122 unregistered source addresses will be aliased (along with those 123 of the ppp host maching itself. Private addresses are those 124 in the following ranges: 125 126 10.0.0.0 -> 10.255.255.255 127 172.16.0.0 -> 172.31.255.255 128 192.168.0.0 -> 192.168.255.255 */ 129 #define PKT_ALIAS_UNREGISTERED_ONLY 0x10 130 131 /* If PKT_ALIAS_RESET_ON_ADDR_CHANGE is set, then the table of dynamic 132 aliasing links will be reset whenever PacketAliasSetAddress() 133 changes the default aliasing address. If the default aliasing 134 address is left unchanged by this functions call, then the 135 table of dynamic aliasing links will be left intact. This 136 bit is set after a call to PacketAliasInit(). */ 137 #define PKT_ALIAS_RESET_ON_ADDR_CHANGE 0x20 138 139 /* Return Codes */ 140 #define PKT_ALIAS_ERROR -1 141 #define PKT_ALIAS_OK 1 142 #define PKT_ALIAS_IGNORED 2 143 #define PKT_ALIAS_UNRESOLVED_FRAGMENT 3 144 #define PKT_ALIAS_FOUND_HEADER_FRAGMENT 4 145 146 #undef __libalias_version 147 #define __libalias_version "2.4" 148 149 #endif 150 /*lint -restore */ 151