/* * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * The contents of this file constitute Original Code as defined in and * are subject to the Apple Public Source License Version 1.1 (the * "License"). You may not use this file except in compliance with the * License. Please obtain a copy of the License at * http://www.apple.com/publicsource and read it before using this file. * * This Original Code and all software distributed under the License are * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the * License for the specific language governing rights and limitations * under the License. * * @APPLE_LICENSE_HEADER_END@ */ /*- * Copyright (c) 1998 Brian Somers <brian@Awfulhak.org> * with the aid of code written by * Junichi SATOH <junichi@astec.co.jp> 1996, 1997. * 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. * * Based upon: * $FreeBSD: src/lib/libalias/alias_cuseeme.c,v 1.2.2.2 2000/10/31 08:48:21 ru Exp $ */ #include <sys/types.h> #include <netinet/in_systm.h> #include <netinet/in.h> #include <netinet/ip.h> #include <netinet/udp.h> #include "alias_local.h" /* CU-SeeMe Data Header */ struct cu_header { u_int16_t dest_family; u_int16_t dest_port; u_int32_t dest_addr; int16_t family; u_int16_t port; u_int32_t addr; u_int32_t seq; u_int16_t msg; u_int16_t data_type; u_int16_t packet_len; }; /* Open Continue Header */ struct oc_header { u_int16_t client_count; /* Number of client info structs */ u_int32_t seq_no; char user_name[20]; char reserved[4]; /* flags, version stuff, etc */ }; /* client info structures */ struct client_info { u_int32_t address; /* Client address */ char reserved[8]; /* Flags, pruning bitfield, packet counts etc */ }; void AliasHandleCUSeeMeOut(struct ip *pip, struct alias_link *link) { struct udphdr *ud; ud = (struct udphdr *)((char *)pip + (pip->ip_hl << 2)); if (ntohs(ud->uh_ulen) - sizeof(struct udphdr) >= sizeof(struct cu_header)) { struct cu_header *cu; struct alias_link *cu_link; cu = (struct cu_header *)(ud + 1); if (cu->addr) cu->addr = (u_int32_t)GetAliasAddress(link).s_addr; cu_link = FindUdpTcpOut(pip->ip_src, GetDestAddress(link), ud->uh_dport, 0, IPPROTO_UDP, 1); #ifndef NO_FW_PUNCH if (cu_link) PunchFWHole(cu_link); #endif } } void AliasHandleCUSeeMeIn(struct ip *pip, struct in_addr original_addr) { struct in_addr alias_addr; struct udphdr *ud; struct cu_header *cu; struct oc_header *oc; struct client_info *ci; char *end; int i; alias_addr.s_addr = pip->ip_dst.s_addr; ud = (struct udphdr *)((char *)pip + (pip->ip_hl << 2)); cu = (struct cu_header *)(ud + 1); oc = (struct oc_header *)(cu + 1); ci = (struct client_info *)(oc + 1); end = (char *)ud + ntohs(ud->uh_ulen); if ((char *)oc <= end) { if(cu->dest_addr) cu->dest_addr = (u_int32_t)original_addr.s_addr; if(ntohs(cu->data_type) == 101) /* Find and change our address */ for(i = 0; (char *)(ci + 1) <= end && i < oc->client_count; i++, ci++) if(ci->address == (u_int32_t)alias_addr.s_addr) { ci->address = (u_int32_t)original_addr.s_addr; break; } } }