1/* 2 * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved. 3 * 4 * @APPLE_LICENSE_HEADER_START@ 5 * 6 * The contents of this file constitute Original Code as defined in and 7 * are subject to the Apple Public Source License Version 1.1 (the 8 * "License"). You may not use this file except in compliance with the 9 * License. Please obtain a copy of the License at 10 * http://www.apple.com/publicsource and read it before using this file. 11 * 12 * This Original Code and all software distributed under the License are 13 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER 14 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 15 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 16 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the 17 * License for the specific language governing rights and limitations 18 * under the License. 19 * 20 * @APPLE_LICENSE_HEADER_END@ 21 */ 22/*- 23 * Copyright (c) 1998 Brian Somers <brian@Awfulhak.org> 24 * with the aid of code written by 25 * Junichi SATOH <junichi@astec.co.jp> 1996, 1997. 26 * All rights reserved. 27 * 28 * Redistribution and use in source and binary forms, with or without 29 * modification, are permitted provided that the following conditions 30 * are met: 31 * 1. Redistributions of source code must retain the above copyright 32 * notice, this list of conditions and the following disclaimer. 33 * 2. Redistributions in binary form must reproduce the above copyright 34 * notice, this list of conditions and the following disclaimer in the 35 * documentation and/or other materials provided with the distribution. 36 * 37 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 38 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 39 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 40 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 41 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 42 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 43 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 45 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 46 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 47 * SUCH DAMAGE. 48 * 49 * Based upon: 50 * $FreeBSD: src/lib/libalias/alias_cuseeme.c,v 1.2.2.2 2000/10/31 08:48:21 ru Exp $ 51 */ 52 53#include <sys/types.h> 54#include <netinet/in_systm.h> 55#include <netinet/in.h> 56#include <netinet/ip.h> 57#include <netinet/udp.h> 58 59#include "alias_local.h" 60 61/* CU-SeeMe Data Header */ 62struct cu_header { 63 u_int16_t dest_family; 64 u_int16_t dest_port; 65 u_int32_t dest_addr; 66 int16_t family; 67 u_int16_t port; 68 u_int32_t addr; 69 u_int32_t seq; 70 u_int16_t msg; 71 u_int16_t data_type; 72 u_int16_t packet_len; 73}; 74 75/* Open Continue Header */ 76struct oc_header { 77 u_int16_t client_count; /* Number of client info structs */ 78 u_int32_t seq_no; 79 char user_name[20]; 80 char reserved[4]; /* flags, version stuff, etc */ 81}; 82 83/* client info structures */ 84struct client_info { 85 u_int32_t address; /* Client address */ 86 char reserved[8]; /* Flags, pruning bitfield, packet counts etc */ 87}; 88 89void 90AliasHandleCUSeeMeOut(struct ip *pip, struct alias_link *link) 91{ 92 struct udphdr *ud; 93 94 ud = (struct udphdr *)((char *)pip + (pip->ip_hl << 2)); 95 if (ntohs(ud->uh_ulen) - sizeof(struct udphdr) >= sizeof(struct cu_header)) { 96 struct cu_header *cu; 97 struct alias_link *cu_link; 98 99 cu = (struct cu_header *)(ud + 1); 100 if (cu->addr) 101 cu->addr = (u_int32_t)GetAliasAddress(link).s_addr; 102 103 cu_link = FindUdpTcpOut(pip->ip_src, GetDestAddress(link), 104 ud->uh_dport, 0, IPPROTO_UDP, 1); 105 106#ifndef NO_FW_PUNCH 107 if (cu_link) 108 PunchFWHole(cu_link); 109#endif 110 } 111} 112 113void 114AliasHandleCUSeeMeIn(struct ip *pip, struct in_addr original_addr) 115{ 116 struct in_addr alias_addr; 117 struct udphdr *ud; 118 struct cu_header *cu; 119 struct oc_header *oc; 120 struct client_info *ci; 121 char *end; 122 int i; 123 124 alias_addr.s_addr = pip->ip_dst.s_addr; 125 ud = (struct udphdr *)((char *)pip + (pip->ip_hl << 2)); 126 cu = (struct cu_header *)(ud + 1); 127 oc = (struct oc_header *)(cu + 1); 128 ci = (struct client_info *)(oc + 1); 129 end = (char *)ud + ntohs(ud->uh_ulen); 130 131 if ((char *)oc <= end) { 132 if(cu->dest_addr) 133 cu->dest_addr = (u_int32_t)original_addr.s_addr; 134 if(ntohs(cu->data_type) == 101) 135 /* Find and change our address */ 136 for(i = 0; (char *)(ci + 1) <= end && i < oc->client_count; i++, ci++) 137 if(ci->address == (u_int32_t)alias_addr.s_addr) { 138 ci->address = (u_int32_t)original_addr.s_addr; 139 break; 140 } 141 } 142} 143