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Diffstat (limited to 'lib/libalias/alias.h')
| -rw-r--r-- | lib/libalias/alias.h | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/lib/libalias/alias.h b/lib/libalias/alias.h new file mode 100644 index 0000000..9df8929 --- /dev/null +++ b/lib/libalias/alias.h @@ -0,0 +1,182 @@ +/* lint -save -library Flexelint comment for external headers */ + +/*- + * Copyright (c) 2001 Charles Mott <cm@linktel.net> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +/*- + * Alias.h defines the outside world interfaces for the packet aliasing + * software. + * + * This software is placed into the public domain with no restrictions on its + * distribution. + */ + +#ifndef _ALIAS_H_ +#define _ALIAS_H_ + +/* The external interface to libalias, the packet aliasing engine. */ + +/* Initialization and control functions. */ +void PacketAliasInit(void); +void PacketAliasSetAddress(struct in_addr _addr); +void PacketAliasSetFWBase(unsigned int _base, unsigned int _num); +unsigned int + PacketAliasSetMode(unsigned int _flags, unsigned int _mask); +void PacketAliasUninit(void); + +/* Packet Handling functions. */ +int PacketAliasIn(char *_ptr, int _maxpacketsize); +int PacketAliasOut(char *_ptr, int _maxpacketsize); +int PacketUnaliasOut(char *_ptr, int _maxpacketsize); + +/* Port and address redirection functions. */ + +/* + * An anonymous structure, a pointer to which is returned from + * PacketAliasRedirectAddr(), PacketAliasRedirectPort() or + * PacketAliasRedirectProto(), passed to PacketAliasAddServer(), + * and freed by PacketAliasRedirectDelete(). + */ +struct alias_link; + +int PacketAliasAddServer(struct alias_link *_link, + struct in_addr _addr, unsigned short _port); +struct alias_link * + PacketAliasRedirectAddr(struct in_addr _src_addr, + struct in_addr _alias_addr); +void PacketAliasRedirectDelete(struct alias_link *_link); +struct alias_link * + PacketAliasRedirectPort(struct in_addr _src_addr, + unsigned short _src_port, struct in_addr _dst_addr, + unsigned short _dst_port, struct in_addr _alias_addr, + unsigned short _alias_port, unsigned char _proto); +struct alias_link * + PacketAliasRedirectProto(struct in_addr _src_addr, + struct in_addr _dst_addr, struct in_addr _alias_addr, + unsigned char _proto); + +/* Fragment Handling functions. */ +void PacketAliasFragmentIn(char *_ptr, char *_ptr_fragment); +char *PacketAliasGetFragment(char *_ptr); +int PacketAliasSaveFragment(char *_ptr); + +/* Miscellaneous functions. */ +int PacketAliasCheckNewLink(void); +unsigned short + PacketAliasInternetChecksum(unsigned short *_ptr, int _nbytes); +void PacketAliasSetTarget(struct in_addr _target_addr); + +/* Transparent proxying routines. */ +int PacketAliasProxyRule(const char *_cmd); + +/* Mode flags, set using PacketAliasSetMode() */ + +/* + * If PKT_ALIAS_LOG is set, a message will be printed to /var/log/alias.log + * every time a link is created or deleted. This is useful for debugging. + */ +#define PKT_ALIAS_LOG 0x01 + +/* + * If PKT_ALIAS_DENY_INCOMING is set, then incoming connections (e.g. to ftp, + * telnet or web servers will be prevented by the aliasing mechanism. + */ +#define PKT_ALIAS_DENY_INCOMING 0x02 + +/* + * If PKT_ALIAS_SAME_PORTS is set, packets will be attempted sent from the + * same port as they originated on. This allows e.g. rsh to work *99% of the + * time*, but _not_ 100% (it will be slightly flakey instead of not working + * at all). This mode bit is set by PacketAliasInit(), so it is a default + * mode of operation. + */ +#define PKT_ALIAS_SAME_PORTS 0x04 + +/* + * If PKT_ALIAS_USE_SOCKETS is set, then when partially specified links (e.g. + * destination port and/or address is zero), the packet aliasing engine will + * attempt to allocate a socket for the aliasing port it chooses. This will + * avoid interference with the host machine. Fully specified links do not + * require this. This bit is set after a call to PacketAliasInit(), so it is + * a default mode of operation. + */ +#define PKT_ALIAS_USE_SOCKETS 0x08 + +/*- + * If PKT_ALIAS_UNREGISTERED_ONLY is set, then only packets with + * unregistered source addresses will be aliased. Private + * addresses are those in the following ranges: + * + * 10.0.0.0 -> 10.255.255.255 + * 172.16.0.0 -> 172.31.255.255 + * 192.168.0.0 -> 192.168.255.255 + */ +#define PKT_ALIAS_UNREGISTERED_ONLY 0x10 + +/* + * If PKT_ALIAS_RESET_ON_ADDR_CHANGE is set, then the table of dynamic + * aliasing links will be reset whenever PacketAliasSetAddress() changes the + * default aliasing address. If the default aliasing address is left + * unchanged by this function call, then the table of dynamic aliasing links + * will be left intact. This bit is set after a call to PacketAliasInit(). + */ +#define PKT_ALIAS_RESET_ON_ADDR_CHANGE 0x20 + +#ifndef NO_FW_PUNCH +/* + * If PKT_ALIAS_PUNCH_FW is set, active FTP and IRC DCC connections will + * create a 'hole' in the firewall to allow the transfers to work. The + * ipfw rule number that the hole is created with is controlled by + * PacketAliasSetFWBase(). The hole will be attached to that + * particular alias_link, so when the link goes away the hole is deleted. + */ +#define PKT_ALIAS_PUNCH_FW 0x100 +#endif + +/* + * If PKT_ALIAS_PROXY_ONLY is set, then NAT will be disabled and only + * transparent proxying is performed. + */ +#define PKT_ALIAS_PROXY_ONLY 0x40 + +/* + * If PKT_ALIAS_REVERSE is set, the actions of PacketAliasIn() and + * PacketAliasOut() are reversed. + */ +#define PKT_ALIAS_REVERSE 0x80 + +/* Function return codes. */ +#define PKT_ALIAS_ERROR -1 +#define PKT_ALIAS_OK 1 +#define PKT_ALIAS_IGNORED 2 +#define PKT_ALIAS_UNRESOLVED_FRAGMENT 3 +#define PKT_ALIAS_FOUND_HEADER_FRAGMENT 4 + +#endif /* !_ALIAS_H_ */ + +/* lint -restore */ |
