alias_dummy.c revision 190841
1162674Spiso/*- 2162674Spiso * Copyright (c) 2005 Paolo Pisati <piso@FreeBSD.org> 3162674Spiso * All rights reserved. 4162674Spiso * 5162674Spiso * Redistribution and use in source and binary forms, with or without 6162674Spiso * modification, are permitted provided that the following conditions 7162674Spiso * are met: 8162674Spiso * 1. Redistributions of source code must retain the above copyright 9162674Spiso * notice, this list of conditions and the following disclaimer. 10162674Spiso * 2. Redistributions in binary form must reproduce the above copyright 11162674Spiso * notice, this list of conditions and the following disclaimer in the 12162674Spiso * documentation and/or other materials provided with the distribution. 13162674Spiso * 14162674Spiso * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15162674Spiso * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16162674Spiso * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17162674Spiso * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18162674Spiso * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19162674Spiso * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20162674Spiso * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21162674Spiso * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22162674Spiso * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23162674Spiso * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24162674Spiso * SUCH DAMAGE. 25162674Spiso */ 26162674Spiso 27162674Spiso#include <sys/cdefs.h> 28162674Spiso__FBSDID("$FreeBSD: head/sys/netinet/libalias/alias_dummy.c 190841 2009-04-08 11:56:49Z piso $"); 29162674Spiso 30162674Spiso/* 31162674Spiso * Alias_dummy is just an empty skeleton used to demostrate how to write 32162674Spiso * a module for libalias, that will run unalterated in userland or in 33162674Spiso * kernel land. 34162674Spiso */ 35162674Spiso 36162674Spiso#ifdef _KERNEL 37162674Spiso#include <sys/param.h> 38162674Spiso#include <sys/kernel.h> 39162674Spiso#include <sys/module.h> 40162674Spiso#else 41162674Spiso#include <errno.h> 42162674Spiso#include <sys/types.h> 43162674Spiso#include <stdio.h> 44162674Spiso#endif 45162674Spiso 46162674Spiso#include <netinet/in_systm.h> 47162674Spiso#include <netinet/in.h> 48162674Spiso#include <netinet/ip.h> 49162674Spiso#include <netinet/udp.h> 50162674Spiso 51162674Spiso#ifdef _KERNEL 52162674Spiso#include <netinet/libalias/alias_local.h> 53162674Spiso#include <netinet/libalias/alias_mod.h> 54162674Spiso#else 55162674Spiso#include "alias_local.h" 56162674Spiso#include "alias_mod.h" 57162674Spiso#endif 58162674Spiso 59162674Spisostatic void 60162674SpisoAliasHandleDummy(struct libalias *la, struct ip *ip, struct alias_data *ah); 61162674Spiso 62162674Spisostatic int 63190841Spisofingerprint(struct libalias *la, struct alias_data *ah) 64162674Spiso{ 65162674Spiso 66162674Spiso /* 67162674Spiso * Check here all the data that will be used later, if any field 68162674Spiso * is empy/NULL, return a -1 value. 69162674Spiso */ 70162674Spiso if (ah->dport == NULL || ah->sport == NULL || ah->lnk == NULL || 71162674Spiso ah->maxpktsize == 0) 72162674Spiso return (-1); 73162674Spiso /* 74162674Spiso * Fingerprint the incoming packet, if it matches any conditions 75162674Spiso * return an OK value. 76162674Spiso */ 77162674Spiso if (ntohs(*ah->dport) == 123 78162674Spiso || ntohs(*ah->sport) == 456) 79162674Spiso return (0); /* I know how to handle it. */ 80162674Spiso return (-1); /* I don't recognize this packet. */ 81162674Spiso} 82162674Spiso 83162674Spiso/* 84162674Spiso * Wrap in this general purpose function, the real function used to alias the 85162674Spiso * packets. 86162674Spiso */ 87162674Spiso 88162674Spisostatic int 89162674Spisoprotohandler(struct libalias *la, struct ip *pip, struct alias_data *ah) 90162674Spiso{ 91162674Spiso 92162674Spiso AliasHandleDummy(la, pip, ah); 93162674Spiso return (0); 94162674Spiso} 95162674Spiso 96162674Spiso/* 97162674Spiso * NOTA BENE: the next variable MUST NOT be renamed in any case if you want 98162674Spiso * your module to work in userland, cause it's used to find and use all 99162674Spiso * the protocol handlers present in every module. 100162674Spiso * So WATCH OUT, your module needs this variables and it needs it with 101162674Spiso * ITS EXACT NAME: handlers. 102162674Spiso */ 103162674Spiso 104162674Spisostruct proto_handler handlers [] = { 105162674Spiso { 106162674Spiso .pri = 666, 107162674Spiso .dir = IN|OUT, 108162674Spiso .proto = UDP|TCP, 109162674Spiso .fingerprint = &fingerprint, 110162674Spiso .protohandler = &protohandler 111162674Spiso }, 112162674Spiso { EOH } 113162674Spiso}; 114162674Spiso 115162674Spisostatic int 116162674Spisomod_handler(module_t mod, int type, void *data) 117162674Spiso{ 118162674Spiso int error; 119162674Spiso 120162674Spiso switch (type) { 121162674Spiso case MOD_LOAD: 122162674Spiso error = 0; 123162674Spiso LibAliasAttachHandlers(handlers); 124162674Spiso break; 125162674Spiso case MOD_UNLOAD: 126162674Spiso error = 0; 127162674Spiso LibAliasDetachHandlers(handlers); 128162674Spiso break; 129162674Spiso default: 130162674Spiso error = EINVAL; 131162674Spiso } 132162674Spiso return (error); 133162674Spiso} 134162674Spiso 135162674Spiso#ifdef _KERNEL 136162674Spisostatic 137162674Spiso#endif 138162674Spisomoduledata_t alias_mod = { 139162674Spiso "alias_dummy", mod_handler, NULL 140162674Spiso}; 141162674Spiso 142162674Spiso#ifdef _KERNEL 143162674SpisoDECLARE_MODULE(alias_dummy, alias_mod, SI_SUB_DRIVERS, SI_ORDER_SECOND); 144162674SpisoMODULE_VERSION(alias_dummy, 1); 145162674SpisoMODULE_DEPEND(alias_dummy, libalias, 1, 1, 1); 146162674Spiso#endif 147162674Spiso 148162674Spisostatic void 149162674SpisoAliasHandleDummy(struct libalias *la, struct ip *ip, struct alias_data *ah) 150162674Spiso{ 151162674Spiso ; /* Dummy. */ 152162674Spiso} 153162674Spiso 154