alias.h revision 164797
1/* lint -save -library Flexelint comment for external headers */ 2 3/*- 4 * Copyright (c) 2001 Charles Mott <cm@linktel.net> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD: head/sys/netinet/libalias/alias.h 164797 2006-12-01 16:27:11Z piso $ 29 */ 30 31/* 32 * Alias.h defines the outside world interfaces for the packet aliasing 33 * software. 34 * 35 * This software is placed into the public domain with no restrictions on its 36 * distribution. 37 */ 38 39#ifndef _ALIAS_H_ 40#define _ALIAS_H_ 41 42#include <netinet/in_systm.h> 43#include <netinet/in.h> 44#include <netinet/ip.h> 45 46#define LIBALIAS_BUF_SIZE 128 47#ifdef _KERNEL 48/* 49 * The kernel version of libalias does not support these features. 50 */ 51#define NO_FW_PUNCH 52#define NO_USE_SOCKETS 53#endif 54 55/* 56 * The external interface to libalias, the packet aliasing engine. 57 * 58 * There are two sets of functions: 59 * 60 * PacketAlias*() the old API which doesn't take an instance pointer 61 * and therefore can only have one packet engine at a time. 62 * 63 * LibAlias*() the new API which takes as first argument a pointer to 64 * the instance of the packet aliasing engine. 65 * 66 * The functions otherwise correspond to each other one for one, except 67 * for the LibAliasUnaliasOut()/PacketUnaliasOut() function which were 68 * were misnamed in the old API. 69 */ 70 71/* 72 * The instance structure 73 */ 74struct libalias; 75 76/* 77 * An anonymous structure, a pointer to which is returned from 78 * PacketAliasRedirectAddr(), PacketAliasRedirectPort() or 79 * PacketAliasRedirectProto(), passed to PacketAliasAddServer(), 80 * and freed by PacketAliasRedirectDelete(). 81 */ 82struct alias_link; 83 84 85/* OLD API */ 86 87/* Initialization and control functions. */ 88void PacketAliasInit(void); 89void PacketAliasSetAddress(struct in_addr _addr); 90void PacketAliasSetFWBase(unsigned int _base, unsigned int _num); 91void PacketAliasSetSkinnyPort(unsigned int _port); 92unsigned int 93 PacketAliasSetMode(unsigned int _flags, unsigned int _mask); 94void PacketAliasUninit(void); 95 96/* Packet Handling functions. */ 97int PacketAliasIn(char *_ptr, int _maxpacketsize); 98int PacketAliasOut(char *_ptr, int _maxpacketsize); 99int PacketUnaliasOut(char *_ptr, int _maxpacketsize); 100 101/* Port and address redirection functions. */ 102 103 104int 105PacketAliasAddServer(struct alias_link *_lnk, 106 struct in_addr _addr, unsigned short _port); 107struct alias_link * 108PacketAliasRedirectAddr(struct in_addr _src_addr, 109 struct in_addr _alias_addr); 110int PacketAliasRedirectDynamic(struct alias_link *_lnk); 111void PacketAliasRedirectDelete(struct alias_link *_lnk); 112struct alias_link * 113PacketAliasRedirectPort(struct in_addr _src_addr, 114 unsigned short _src_port, struct in_addr _dst_addr, 115 unsigned short _dst_port, struct in_addr _alias_addr, 116 unsigned short _alias_port, unsigned char _proto); 117struct alias_link * 118PacketAliasRedirectProto(struct in_addr _src_addr, 119 struct in_addr _dst_addr, struct in_addr _alias_addr, 120 unsigned char _proto); 121 122/* Fragment Handling functions. */ 123void PacketAliasFragmentIn(char *_ptr, char *_ptr_fragment); 124char *PacketAliasGetFragment(char *_ptr); 125int PacketAliasSaveFragment(char *_ptr); 126 127/* Miscellaneous functions. */ 128int PacketAliasCheckNewLink(void); 129unsigned short 130 PacketAliasInternetChecksum(unsigned short *_ptr, int _nbytes); 131void PacketAliasSetTarget(struct in_addr _target_addr); 132 133/* Transparent proxying routines. */ 134int PacketAliasProxyRule(const char *_cmd); 135 136/* NEW API */ 137 138/* Initialization and control functions. */ 139struct libalias *LibAliasInit(struct libalias *); 140void LibAliasSetAddress(struct libalias *, struct in_addr _addr); 141void LibAliasSetFWBase(struct libalias *, unsigned int _base, unsigned int _num); 142void LibAliasSetSkinnyPort(struct libalias *, unsigned int _port); 143unsigned int 144 LibAliasSetMode(struct libalias *, unsigned int _flags, unsigned int _mask); 145void LibAliasUninit(struct libalias *); 146 147/* Packet Handling functions. */ 148int LibAliasIn (struct libalias *, char *_ptr, int _maxpacketsize); 149int LibAliasOut(struct libalias *, char *_ptr, int _maxpacketsize); 150int LibAliasOutTry(struct libalias *, char *_ptr, int _maxpacketsize, int _create); 151int LibAliasUnaliasOut(struct libalias *, char *_ptr, int _maxpacketsize); 152 153/* Port and address redirection functions. */ 154 155int 156LibAliasAddServer(struct libalias *, struct alias_link *_lnk, 157 struct in_addr _addr, unsigned short _port); 158struct alias_link * 159LibAliasRedirectAddr(struct libalias *, struct in_addr _src_addr, 160 struct in_addr _alias_addr); 161int LibAliasRedirectDynamic(struct libalias *, struct alias_link *_lnk); 162void LibAliasRedirectDelete(struct libalias *, struct alias_link *_lnk); 163struct alias_link * 164LibAliasRedirectPort(struct libalias *, struct in_addr _src_addr, 165 unsigned short _src_port, struct in_addr _dst_addr, 166 unsigned short _dst_port, struct in_addr _alias_addr, 167 unsigned short _alias_port, unsigned char _proto); 168struct alias_link * 169LibAliasRedirectProto(struct libalias *, struct in_addr _src_addr, 170 struct in_addr _dst_addr, struct in_addr _alias_addr, 171 unsigned char _proto); 172 173/* Fragment Handling functions. */ 174void LibAliasFragmentIn(struct libalias *, char *_ptr, char *_ptr_fragment); 175char *LibAliasGetFragment(struct libalias *, char *_ptr); 176int LibAliasSaveFragment(struct libalias *, char *_ptr); 177 178/* Miscellaneous functions. */ 179int LibAliasCheckNewLink(struct libalias *); 180unsigned short 181 LibAliasInternetChecksum(struct libalias *, unsigned short *_ptr, int _nbytes); 182void LibAliasSetTarget(struct libalias *, struct in_addr _target_addr); 183 184/* Transparent proxying routines. */ 185int LibAliasProxyRule(struct libalias *, const char *_cmd); 186 187/* Module handling API */ 188int LibAliasLoadModule(char *); 189int LibAliasUnLoadAllModule(void); 190int LibAliasRefreshModules(void); 191 192/* Mbuf helper function. */ 193struct mbuf *m_megapullup(struct mbuf *, int); 194 195/* 196 * Mode flags and other constants. 197 */ 198 199 200/* Mode flags, set using PacketAliasSetMode() */ 201 202/* 203 * If PKT_ALIAS_LOG is set, a message will be printed to /var/log/alias.log 204 * every time a link is created or deleted. This is useful for debugging. 205 */ 206#define PKT_ALIAS_LOG 0x01 207 208/* 209 * If PKT_ALIAS_DENY_INCOMING is set, then incoming connections (e.g. to ftp, 210 * telnet or web servers will be prevented by the aliasing mechanism. 211 */ 212#define PKT_ALIAS_DENY_INCOMING 0x02 213 214/* 215 * If PKT_ALIAS_SAME_PORTS is set, packets will be attempted sent from the 216 * same port as they originated on. This allows e.g. rsh to work *99% of the 217 * time*, but _not_ 100% (it will be slightly flakey instead of not working 218 * at all). This mode bit is set by PacketAliasInit(), so it is a default 219 * mode of operation. 220 */ 221#define PKT_ALIAS_SAME_PORTS 0x04 222 223/* 224 * If PKT_ALIAS_USE_SOCKETS is set, then when partially specified links (e.g. 225 * destination port and/or address is zero), the packet aliasing engine will 226 * attempt to allocate a socket for the aliasing port it chooses. This will 227 * avoid interference with the host machine. Fully specified links do not 228 * require this. This bit is set after a call to PacketAliasInit(), so it is 229 * a default mode of operation. 230 */ 231#ifndef NO_USE_SOCKETS 232#define PKT_ALIAS_USE_SOCKETS 0x08 233#endif 234/*- 235 * If PKT_ALIAS_UNREGISTERED_ONLY is set, then only packets with 236 * unregistered source addresses will be aliased. Private 237 * addresses are those in the following ranges: 238 * 239 * 10.0.0.0 -> 10.255.255.255 240 * 172.16.0.0 -> 172.31.255.255 241 * 192.168.0.0 -> 192.168.255.255 242 */ 243#define PKT_ALIAS_UNREGISTERED_ONLY 0x10 244 245/* 246 * If PKT_ALIAS_RESET_ON_ADDR_CHANGE is set, then the table of dynamic 247 * aliasing links will be reset whenever PacketAliasSetAddress() changes the 248 * default aliasing address. If the default aliasing address is left 249 * unchanged by this function call, then the table of dynamic aliasing links 250 * will be left intact. This bit is set after a call to PacketAliasInit(). 251 */ 252#define PKT_ALIAS_RESET_ON_ADDR_CHANGE 0x20 253 254#ifndef NO_FW_PUNCH 255/* 256 * If PKT_ALIAS_PUNCH_FW is set, active FTP and IRC DCC connections will 257 * create a 'hole' in the firewall to allow the transfers to work. The 258 * ipfw rule number that the hole is created with is controlled by 259 * PacketAliasSetFWBase(). The hole will be attached to that 260 * particular alias_link, so when the link goes away the hole is deleted. 261 */ 262#define PKT_ALIAS_PUNCH_FW 0x100 263#endif 264 265/* 266 * If PKT_ALIAS_PROXY_ONLY is set, then NAT will be disabled and only 267 * transparent proxying is performed. 268 */ 269#define PKT_ALIAS_PROXY_ONLY 0x40 270 271/* 272 * If PKT_ALIAS_REVERSE is set, the actions of PacketAliasIn() and 273 * PacketAliasOut() are reversed. 274 */ 275#define PKT_ALIAS_REVERSE 0x80 276 277/* Function return codes. */ 278#define PKT_ALIAS_ERROR -1 279#define PKT_ALIAS_OK 1 280#define PKT_ALIAS_IGNORED 2 281#define PKT_ALIAS_UNRESOLVED_FRAGMENT 3 282#define PKT_ALIAS_FOUND_HEADER_FRAGMENT 4 283 284#endif /* !_ALIAS_H_ */ 285 286/* lint -restore */ 287