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 $FreeBSD$ 11 */ 12 13 14 #ifndef _ALIAS_H_ 15 #define _ALIAS_H_ 16 17 /* Alias link representative (incomplete struct) */ 18 struct alias_link; 19 20 /* External interfaces (API) to packet aliasing engine */ 21 22 /* Initialization and Control */ 23 extern void 24 PacketAliasInit(void); 25 26 extern void 27 PacketAliasUninit(void); 28 29 extern void 30 PacketAliasSetAddress(struct in_addr); 31 32 extern unsigned int 33 PacketAliasSetMode(unsigned int, unsigned int); 34 35 #ifndef NO_FW_PUNCH 36 extern void 37 PacketAliasSetFWBase(unsigned int, unsigned int); 38 #endif 39 40 /* Packet Handling */ 41 extern int 42 PacketAliasIn(char *, int maxpacketsize); 43 44 extern int 45 PacketAliasOut(char *, int maxpacketsize); 46 47 /* Port and Address Redirection */ 48 extern struct alias_link * 49 PacketAliasRedirectPort(struct in_addr, u_short, 50 struct in_addr, u_short, 51 struct in_addr, u_short, 52 u_char); 53 54 extern int 55 PacketAliasAddServer(struct alias_link *link, 56 struct in_addr addr, 57 u_short port); 58 59 extern struct alias_link * 60 PacketAliasRedirectProto(struct in_addr, 61 struct in_addr, 62 struct in_addr, 63 u_char); 64 65 extern struct alias_link * 66 PacketAliasRedirectAddr(struct in_addr, 67 struct in_addr); 68 69 extern void 70 PacketAliasRedirectDelete(struct alias_link *); 71 72 /* Fragment Handling */ 73 extern int 74 PacketAliasSaveFragment(char *); 75 76 extern char * 77 PacketAliasGetFragment(char *); 78 79 extern void 80 PacketAliasFragmentIn(char *, char *); 81 82 /* Miscellaneous Functions */ 83 extern void 84 PacketAliasSetTarget(struct in_addr addr); 85 86 extern int 87 PacketAliasCheckNewLink(void); 88 89 extern u_short 90 PacketAliasInternetChecksum(u_short *, int); 91 92 /* Transparent Proxying */ 93 extern int 94 PacketAliasProxyRule(const char *); 95 96 97 /********************** Mode flags ********************/ 98 /* Set these flags using PacketAliasSetMode() */ 99 100 /* If PKT_ALIAS_LOG is set, a message will be printed to 101 /var/log/alias.log every time a link is created or deleted. This 102 is useful for debugging */ 103 #define PKT_ALIAS_LOG 0x01 104 105 /* If PKT_ALIAS_DENY_INCOMING is set, then incoming connections (e.g. 106 to ftp, telnet or web servers will be prevented by the aliasing 107 mechanism. */ 108 #define PKT_ALIAS_DENY_INCOMING 0x02 109 110 /* If PKT_ALIAS_SAME_PORTS is set, packets will be attempted sent from 111 the same port as they originated on. This allows e.g. rsh to work 112 *99% of the time*, but _not_ 100%. (It will be slightly flakey 113 instead of not working at all.) This mode bit is set by 114 PacketAliasInit(), so it is a default mode of operation. */ 115 #define PKT_ALIAS_SAME_PORTS 0x04 116 117 /* If PKT_ALIAS_USE_SOCKETS is set, then when partially specified 118 links (e.g. destination port and/or address is zero), the packet 119 aliasing engine will attempt to allocate a socket for the aliasing 120 port it chooses. This will avoid interference with the host 121 machine. Fully specified links do not require this. This bit 122 is set after a call to PacketAliasInit(), so it is a default 123 mode of operation. */ 124 #define PKT_ALIAS_USE_SOCKETS 0x08 125 126 /* If PKT_ALIAS_UNREGISTERED_ONLY is set, then only packets with 127 unregistered source addresses will be aliased. Private 128 addresses are those in the following ranges: 129 10.0.0.0 -> 10.255.255.255 130 172.16.0.0 -> 172.31.255.255 131 192.168.0.0 -> 192.168.255.255 */ 132 #define PKT_ALIAS_UNREGISTERED_ONLY 0x10 133 134 /* If PKT_ALIAS_RESET_ON_ADDR_CHANGE is set, then the table of dynamic 135 aliasing links will be reset whenever PacketAliasSetAddress() 136 changes the default aliasing address. If the default aliasing 137 address is left unchanged by this function call, then the 138 table of dynamic aliasing links will be left intact. This 139 bit is set after a call to PacketAliasInit(). */ 140 #define PKT_ALIAS_RESET_ON_ADDR_CHANGE 0x20 141 142 #ifndef NO_FW_PUNCH 143 /* If PKT_ALIAS_PUNCH_FW is set, active FTP and IRC DCC connections 144 will create a 'hole' in the firewall to allow the transfers to 145 work. Where (IPFW "line-numbers") the hole is created is 146 controlled by PacketAliasSetFWBase(base, size). The hole will be 147 attached to that particular alias_link, so when the link goes away 148 so do the hole. */ 149 #define PKT_ALIAS_PUNCH_FW 0x100 150 #endif 151 152 /* If PKT_ALIAS_PROXY_ONLY is set, then NAT will be disabled and only 153 transparent proxying performed */ 154 #define PKT_ALIAS_PROXY_ONLY 0x40 155 156 /* If PKT_ALIAS_REVERSE is set, the actions of PacketAliasIn() 157 and PacketAliasOut() are reversed */ 158 #define PKT_ALIAS_REVERSE 0x80 159 160 /* Return Codes */ 161 #define PKT_ALIAS_ERROR -1 162 #define PKT_ALIAS_OK 1 163 #define PKT_ALIAS_IGNORED 2 164 #define PKT_ALIAS_UNRESOLVED_FRAGMENT 3 165 #define PKT_ALIAS_FOUND_HEADER_FRAGMENT 4 166 167 #endif 168 /*lint -restore */ 169