alias.h revision 145926
191094Sdes/* lint -save -library Flexelint comment for external headers */ 2115619Sdes 3228690Sdes/*- 491094Sdes * Copyright (c) 2001 Charles Mott <cm@linktel.net> 591094Sdes * All rights reserved. 691094Sdes * 799158Sdes * Redistribution and use in source and binary forms, with or without 899158Sdes * modification, are permitted provided that the following conditions 999158Sdes * are met: 1091094Sdes * 1. Redistributions of source code must retain the above copyright 1191094Sdes * notice, this list of conditions and the following disclaimer. 1291094Sdes * 2. Redistributions in binary form must reproduce the above copyright 1391094Sdes * notice, this list of conditions and the following disclaimer in the 1491094Sdes * documentation and/or other materials provided with the distribution. 1591094Sdes * 1691094Sdes * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 1791094Sdes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1891094Sdes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1991094Sdes * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 2091094Sdes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2191094Sdes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2291094Sdes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2391094Sdes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2491094Sdes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2591094Sdes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2691094Sdes * SUCH DAMAGE. 2791094Sdes * 2891094Sdes * $FreeBSD: head/sys/netinet/libalias/alias.h 145926 2005-05-05 20:25:12Z glebius $ 2991094Sdes */ 3091094Sdes 3191094Sdes/*- 3291094Sdes * Alias.h defines the outside world interfaces for the packet aliasing 3391094Sdes * software. 3491094Sdes * 35255376Sdes * This software is placed into the public domain with no restrictions on its 3691094Sdes * distribution. 3791094Sdes */ 38228690Sdes 39228690Sdes#ifndef _ALIAS_H_ 40228690Sdes#define _ALIAS_H_ 41228690Sdes 4291094Sdes/* 4391094Sdes * The external interface to libalias, the packet aliasing engine. 4491094Sdes * 4591094Sdes * There are two sets of functions: 4691094Sdes * 4791094Sdes * PacketAlias*() the old API which doesn't take an instance pointer 4891094Sdes * and therefore can only have one packet engine at a time. 4991094Sdes * 5091094Sdes * LibAlias*() the new API which takes as first argument a pointer to 5191094Sdes * the instance of the packet aliasing engine. 5291094Sdes * 5391094Sdes * The functions otherwise correspond to each other one for one, except 5491094Sdes * for the LibAliasUnaliasOut()/PacketUnaliasOut() function which were 5591094Sdes * were misnamed in the old API. 56114536Sdes */ 5791094Sdes 5891094Sdes/* 5991094Sdes * The instance structure 60110558Sdes */ 6191094Sdesstruct libalias; 6291094Sdes 63110558Sdes/* 6491094Sdes * An anonymous structure, a pointer to which is returned from 65108794Sdes * PacketAliasRedirectAddr(), PacketAliasRedirectPort() or 6691094Sdes * PacketAliasRedirectProto(), passed to PacketAliasAddServer(), 67108794Sdes * and freed by PacketAliasRedirectDelete(). 68115619Sdes */ 69108794Sdesstruct alias_link; 70110558Sdes 71110558Sdes 72110558Sdes/* OLD API */ 73110558Sdes 74110558Sdes/* Initialization and control functions. */ 75110558Sdesvoid PacketAliasInit(void); 76110558Sdesvoid PacketAliasSetAddress(struct in_addr _addr); 7791094Sdesvoid PacketAliasSetFWBase(unsigned int _base, unsigned int _num); 7891100Sdesvoid PacketAliasSetSkinnyPort(unsigned int _port); 7991100Sdesunsigned int 8091100Sdes PacketAliasSetMode(unsigned int _flags, unsigned int _mask); 8191100Sdesvoid PacketAliasUninit(void); 8291100Sdes 8391100Sdes/* Packet Handling functions. */ 8491100Sdesint PacketAliasIn(char *_ptr, int _maxpacketsize); 8591100Sdesint PacketAliasOut(char *_ptr, int _maxpacketsize); 8691100Sdesint PacketUnaliasOut(char *_ptr, int _maxpacketsize); 8791100Sdes 88/* Port and address redirection functions. */ 89 90 91int 92PacketAliasAddServer(struct alias_link *_lnk, 93 struct in_addr _addr, unsigned short _port); 94struct alias_link * 95PacketAliasRedirectAddr(struct in_addr _src_addr, 96 struct in_addr _alias_addr); 97int PacketAliasRedirectDynamic(struct alias_link *_lnk); 98void PacketAliasRedirectDelete(struct alias_link *_lnk); 99struct alias_link * 100PacketAliasRedirectPort(struct in_addr _src_addr, 101 unsigned short _src_port, struct in_addr _dst_addr, 102 unsigned short _dst_port, struct in_addr _alias_addr, 103 unsigned short _alias_port, unsigned char _proto); 104struct alias_link * 105PacketAliasRedirectProto(struct in_addr _src_addr, 106 struct in_addr _dst_addr, struct in_addr _alias_addr, 107 unsigned char _proto); 108 109/* Fragment Handling functions. */ 110void PacketAliasFragmentIn(char *_ptr, char *_ptr_fragment); 111char *PacketAliasGetFragment(char *_ptr); 112int PacketAliasSaveFragment(char *_ptr); 113 114/* Miscellaneous functions. */ 115int PacketAliasCheckNewLink(void); 116unsigned short 117 PacketAliasInternetChecksum(unsigned short *_ptr, int _nbytes); 118void PacketAliasSetTarget(struct in_addr _target_addr); 119 120/* Transparent proxying routines. */ 121int PacketAliasProxyRule(const char *_cmd); 122 123/* NEW API */ 124 125/* Initialization and control functions. */ 126struct libalias *LibAliasInit(struct libalias *); 127void LibAliasSetAddress(struct libalias *, struct in_addr _addr); 128void LibAliasSetFWBase(struct libalias *, unsigned int _base, unsigned int _num); 129void LibAliasSetSkinnyPort(struct libalias *, unsigned int _port); 130unsigned int 131 LibAliasSetMode(struct libalias *, unsigned int _flags, unsigned int _mask); 132void LibAliasUninit(struct libalias *); 133 134/* Packet Handling functions. */ 135int LibAliasIn (struct libalias *, char *_ptr, int _maxpacketsize); 136int LibAliasOut(struct libalias *, char *_ptr, int _maxpacketsize); 137int LibAliasOutTry(struct libalias *, char *_ptr, int _maxpacketsize, int _create); 138int LibAliasUnaliasOut(struct libalias *, char *_ptr, int _maxpacketsize); 139 140/* Port and address redirection functions. */ 141 142int 143LibAliasAddServer(struct libalias *, struct alias_link *_lnk, 144 struct in_addr _addr, unsigned short _port); 145struct alias_link * 146LibAliasRedirectAddr(struct libalias *, struct in_addr _src_addr, 147 struct in_addr _alias_addr); 148int LibAliasRedirectDynamic(struct libalias *, struct alias_link *_lnk); 149void LibAliasRedirectDelete(struct libalias *, struct alias_link *_lnk); 150struct alias_link * 151LibAliasRedirectPort(struct libalias *, struct in_addr _src_addr, 152 unsigned short _src_port, struct in_addr _dst_addr, 153 unsigned short _dst_port, struct in_addr _alias_addr, 154 unsigned short _alias_port, unsigned char _proto); 155struct alias_link * 156LibAliasRedirectProto(struct libalias *, struct in_addr _src_addr, 157 struct in_addr _dst_addr, struct in_addr _alias_addr, 158 unsigned char _proto); 159 160/* Fragment Handling functions. */ 161void LibAliasFragmentIn(struct libalias *, char *_ptr, char *_ptr_fragment); 162char *LibAliasGetFragment(struct libalias *, char *_ptr); 163int LibAliasSaveFragment(struct libalias *, char *_ptr); 164 165/* Miscellaneous functions. */ 166int LibAliasCheckNewLink(struct libalias *); 167unsigned short 168 LibAliasInternetChecksum(struct libalias *, unsigned short *_ptr, int _nbytes); 169void LibAliasSetTarget(struct libalias *, struct in_addr _target_addr); 170 171/* Transparent proxying routines. */ 172int LibAliasProxyRule(struct libalias *, const char *_cmd); 173 174 175/* 176 * Mode flags and other constants. 177 */ 178 179 180/* Mode flags, set using PacketAliasSetMode() */ 181 182/* 183 * If PKT_ALIAS_LOG is set, a message will be printed to /var/log/alias.log 184 * every time a link is created or deleted. This is useful for debugging. 185 */ 186#ifndef NO_LOGGING 187#define PKT_ALIAS_LOG 0x01 188#endif 189 190/* 191 * If PKT_ALIAS_DENY_INCOMING is set, then incoming connections (e.g. to ftp, 192 * telnet or web servers will be prevented by the aliasing mechanism. 193 */ 194#define PKT_ALIAS_DENY_INCOMING 0x02 195 196/* 197 * If PKT_ALIAS_SAME_PORTS is set, packets will be attempted sent from the 198 * same port as they originated on. This allows e.g. rsh to work *99% of the 199 * time*, but _not_ 100% (it will be slightly flakey instead of not working 200 * at all). This mode bit is set by PacketAliasInit(), so it is a default 201 * mode of operation. 202 */ 203#define PKT_ALIAS_SAME_PORTS 0x04 204 205/* 206 * If PKT_ALIAS_USE_SOCKETS is set, then when partially specified links (e.g. 207 * destination port and/or address is zero), the packet aliasing engine will 208 * attempt to allocate a socket for the aliasing port it chooses. This will 209 * avoid interference with the host machine. Fully specified links do not 210 * require this. This bit is set after a call to PacketAliasInit(), so it is 211 * a default mode of operation. 212 */ 213#ifndef NO_USE_SOCKETS 214#define PKT_ALIAS_USE_SOCKETS 0x08 215#endif 216/*- 217 * If PKT_ALIAS_UNREGISTERED_ONLY is set, then only packets with 218 * unregistered source addresses will be aliased. Private 219 * addresses are those in the following ranges: 220 * 221 * 10.0.0.0 -> 10.255.255.255 222 * 172.16.0.0 -> 172.31.255.255 223 * 192.168.0.0 -> 192.168.255.255 224 */ 225#define PKT_ALIAS_UNREGISTERED_ONLY 0x10 226 227/* 228 * If PKT_ALIAS_RESET_ON_ADDR_CHANGE is set, then the table of dynamic 229 * aliasing links will be reset whenever PacketAliasSetAddress() changes the 230 * default aliasing address. If the default aliasing address is left 231 * unchanged by this function call, then the table of dynamic aliasing links 232 * will be left intact. This bit is set after a call to PacketAliasInit(). 233 */ 234#define PKT_ALIAS_RESET_ON_ADDR_CHANGE 0x20 235 236#ifndef NO_FW_PUNCH 237/* 238 * If PKT_ALIAS_PUNCH_FW is set, active FTP and IRC DCC connections will 239 * create a 'hole' in the firewall to allow the transfers to work. The 240 * ipfw rule number that the hole is created with is controlled by 241 * PacketAliasSetFWBase(). The hole will be attached to that 242 * particular alias_link, so when the link goes away the hole is deleted. 243 */ 244#define PKT_ALIAS_PUNCH_FW 0x100 245#endif 246 247/* 248 * If PKT_ALIAS_PROXY_ONLY is set, then NAT will be disabled and only 249 * transparent proxying is performed. 250 */ 251#define PKT_ALIAS_PROXY_ONLY 0x40 252 253/* 254 * If PKT_ALIAS_REVERSE is set, the actions of PacketAliasIn() and 255 * PacketAliasOut() are reversed. 256 */ 257#define PKT_ALIAS_REVERSE 0x80 258 259/* Function return codes. */ 260#define PKT_ALIAS_ERROR -1 261#define PKT_ALIAS_OK 1 262#define PKT_ALIAS_IGNORED 2 263#define PKT_ALIAS_UNRESOLVED_FRAGMENT 3 264#define PKT_ALIAS_FOUND_HEADER_FRAGMENT 4 265 266#endif /* !_ALIAS_H_ */ 267 268/* lint -restore */ 269