alias.h revision 120372
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 120372 2003-09-23 07:41:55Z marcus $ 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/* The external interface to libalias, the packet aliasing engine. */ 43 44/* Initialization and control functions. */ 45void PacketAliasInit(void); 46void PacketAliasSetAddress(struct in_addr _addr); 47void PacketAliasSetFWBase(unsigned int _base, unsigned int _num); 48void PacketAliasSetSkinnyPort(unsigned int _port); 49unsigned int 50 PacketAliasSetMode(unsigned int _flags, unsigned int _mask); 51void PacketAliasUninit(void); 52 53/* Packet Handling functions. */ 54int PacketAliasIn(char *_ptr, int _maxpacketsize); 55int PacketAliasOut(char *_ptr, int _maxpacketsize); 56int PacketUnaliasOut(char *_ptr, int _maxpacketsize); 57 58/* Port and address redirection functions. */ 59 60/* 61 * An anonymous structure, a pointer to which is returned from 62 * PacketAliasRedirectAddr(), PacketAliasRedirectPort() or 63 * PacketAliasRedirectProto(), passed to PacketAliasAddServer(), 64 * and freed by PacketAliasRedirectDelete(). 65 */ 66struct alias_link; 67 68int PacketAliasAddServer(struct alias_link *_link, 69 struct in_addr _addr, unsigned short _port); 70struct alias_link * 71 PacketAliasRedirectAddr(struct in_addr _src_addr, 72 struct in_addr _alias_addr); 73int PacketAliasRedirectDynamic(struct alias_link *_link); 74void PacketAliasRedirectDelete(struct alias_link *_link); 75struct alias_link * 76 PacketAliasRedirectPort(struct in_addr _src_addr, 77 unsigned short _src_port, struct in_addr _dst_addr, 78 unsigned short _dst_port, struct in_addr _alias_addr, 79 unsigned short _alias_port, unsigned char _proto); 80struct alias_link * 81 PacketAliasRedirectProto(struct in_addr _src_addr, 82 struct in_addr _dst_addr, struct in_addr _alias_addr, 83 unsigned char _proto); 84 85/* Fragment Handling functions. */ 86void PacketAliasFragmentIn(char *_ptr, char *_ptr_fragment); 87char *PacketAliasGetFragment(char *_ptr); 88int PacketAliasSaveFragment(char *_ptr); 89 90/* Miscellaneous functions. */ 91int PacketAliasCheckNewLink(void); 92unsigned short 93 PacketAliasInternetChecksum(unsigned short *_ptr, int _nbytes); 94void PacketAliasSetTarget(struct in_addr _target_addr); 95 96/* Transparent proxying routines. */ 97int PacketAliasProxyRule(const char *_cmd); 98 99/* Mode flags, set using PacketAliasSetMode() */ 100 101/* 102 * If PKT_ALIAS_LOG is set, a message will be printed to /var/log/alias.log 103 * every time a link is created or deleted. This is useful for debugging. 104 */ 105#define PKT_ALIAS_LOG 0x01 106 107/* 108 * If PKT_ALIAS_DENY_INCOMING is set, then incoming connections (e.g. to ftp, 109 * telnet or web servers will be prevented by the aliasing mechanism. 110 */ 111#define PKT_ALIAS_DENY_INCOMING 0x02 112 113/* 114 * If PKT_ALIAS_SAME_PORTS is set, packets will be attempted sent from the 115 * same port as they originated on. This allows e.g. rsh to work *99% of the 116 * time*, but _not_ 100% (it will be slightly flakey instead of not working 117 * at all). This mode bit is set by PacketAliasInit(), so it is a default 118 * mode of operation. 119 */ 120#define PKT_ALIAS_SAME_PORTS 0x04 121 122/* 123 * If PKT_ALIAS_USE_SOCKETS is set, then when partially specified links (e.g. 124 * destination port and/or address is zero), the packet aliasing engine will 125 * attempt to allocate a socket for the aliasing port it chooses. This will 126 * avoid interference with the host machine. Fully specified links do not 127 * require this. This bit is set after a call to PacketAliasInit(), so it is 128 * a default mode of operation. 129 */ 130#define PKT_ALIAS_USE_SOCKETS 0x08 131 132/*- 133 * If PKT_ALIAS_UNREGISTERED_ONLY is set, then only packets with 134 * unregistered source addresses will be aliased. Private 135 * addresses are those in the following ranges: 136 * 137 * 10.0.0.0 -> 10.255.255.255 138 * 172.16.0.0 -> 172.31.255.255 139 * 192.168.0.0 -> 192.168.255.255 140 */ 141#define PKT_ALIAS_UNREGISTERED_ONLY 0x10 142 143/* 144 * If PKT_ALIAS_RESET_ON_ADDR_CHANGE is set, then the table of dynamic 145 * aliasing links will be reset whenever PacketAliasSetAddress() changes the 146 * default aliasing address. If the default aliasing address is left 147 * unchanged by this function call, then the table of dynamic aliasing links 148 * will be left intact. This bit is set after a call to PacketAliasInit(). 149 */ 150#define PKT_ALIAS_RESET_ON_ADDR_CHANGE 0x20 151 152#ifndef NO_FW_PUNCH 153/* 154 * If PKT_ALIAS_PUNCH_FW is set, active FTP and IRC DCC connections will 155 * create a 'hole' in the firewall to allow the transfers to work. The 156 * ipfw rule number that the hole is created with is controlled by 157 * PacketAliasSetFWBase(). The hole will be attached to that 158 * particular alias_link, so when the link goes away the hole is deleted. 159 */ 160#define PKT_ALIAS_PUNCH_FW 0x100 161#endif 162 163/* 164 * If PKT_ALIAS_PROXY_ONLY is set, then NAT will be disabled and only 165 * transparent proxying is performed. 166 */ 167#define PKT_ALIAS_PROXY_ONLY 0x40 168 169/* 170 * If PKT_ALIAS_REVERSE is set, the actions of PacketAliasIn() and 171 * PacketAliasOut() are reversed. 172 */ 173#define PKT_ALIAS_REVERSE 0x80 174 175/* Function return codes. */ 176#define PKT_ALIAS_ERROR -1 177#define PKT_ALIAS_OK 1 178#define PKT_ALIAS_IGNORED 2 179#define PKT_ALIAS_UNRESOLVED_FRAGMENT 3 180#define PKT_ALIAS_FOUND_HEADER_FRAGMENT 4 181 182#endif /* !_ALIAS_H_ */ 183 184/* lint -restore */ 185