alias_cuseeme.c revision 145932
137131Sbrian/*- 237131Sbrian * Copyright (c) 1998 Brian Somers <brian@Awfulhak.org> 337131Sbrian * with the aid of code written by 437131Sbrian * Junichi SATOH <junichi@astec.co.jp> 1996, 1997. 537131Sbrian * All rights reserved. 637131Sbrian * 737131Sbrian * Redistribution and use in source and binary forms, with or without 837131Sbrian * modification, are permitted provided that the following conditions 937131Sbrian * are met: 1037131Sbrian * 1. Redistributions of source code must retain the above copyright 1137131Sbrian * notice, this list of conditions and the following disclaimer. 1237131Sbrian * 2. Redistributions in binary form must reproduce the above copyright 1337131Sbrian * notice, this list of conditions and the following disclaimer in the 1437131Sbrian * documentation and/or other materials provided with the distribution. 1537131Sbrian * 1637131Sbrian * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 1737131Sbrian * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1837131Sbrian * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1937131Sbrian * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 2037131Sbrian * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2137131Sbrian * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2237131Sbrian * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2337131Sbrian * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2437131Sbrian * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2537131Sbrian * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2637131Sbrian * SUCH DAMAGE. 2737131Sbrian */ 2837131Sbrian 2984195Sdillon#include <sys/cdefs.h> 3084195Sdillon__FBSDID("$FreeBSD: head/sys/netinet/libalias/alias_cuseeme.c 145932 2005-05-05 21:55:17Z glebius $"); 3184195Sdillon 32145921Sglebius#ifdef _KERNEL 33145921Sglebius#include <sys/param.h> 34145921Sglebius#else 35145921Sglebius#include <sys/types.h> 36124621Sphk#include <stdio.h> 37145921Sglebius#endif 38145921Sglebius 3937131Sbrian#include <netinet/in_systm.h> 4037131Sbrian#include <netinet/in.h> 4137131Sbrian#include <netinet/ip.h> 4237131Sbrian#include <netinet/udp.h> 4337131Sbrian 44145921Sglebius#ifdef _KERNEL 45145932Sglebius#include <netinet/libalias/alias.h> 46145921Sglebius#include <netinet/libalias/alias_local.h> 47145921Sglebius#else 4837131Sbrian#include "alias_local.h" 49145921Sglebius#endif 5037131Sbrian 5137131Sbrian/* CU-SeeMe Data Header */ 5237131Sbrianstruct cu_header { 53127094Sdes u_int16_t dest_family; 54127094Sdes u_int16_t dest_port; 55127094Sdes u_int32_t dest_addr; 56127094Sdes int16_t family; 57127094Sdes u_int16_t port; 58127094Sdes u_int32_t addr; 59127094Sdes u_int32_t seq; 60127094Sdes u_int16_t msg; 61127094Sdes u_int16_t data_type; 62127094Sdes u_int16_t packet_len; 6337131Sbrian}; 6437131Sbrian 6537131Sbrian/* Open Continue Header */ 6637131Sbrianstruct oc_header { 67127094Sdes u_int16_t client_count; /* Number of client info structs */ 68127094Sdes u_int32_t seq_no; 69127094Sdes char user_name [20]; 70127094Sdes char reserved [4]; /* flags, version stuff, etc */ 7137131Sbrian}; 7237131Sbrian 7337131Sbrian/* client info structures */ 7437131Sbrianstruct client_info { 75127094Sdes u_int32_t address;/* Client address */ 76127094Sdes char reserved [8]; /* Flags, pruning bitfield, packet 77127094Sdes * counts etc */ 7837131Sbrian}; 7937131Sbrian 8037131Sbrianvoid 81131614SdesAliasHandleCUSeeMeOut(struct libalias *la, struct ip *pip, struct alias_link *lnk) 8237131Sbrian{ 83131699Sdes struct udphdr *ud = ip_next(pip); 8437131Sbrian 85127094Sdes if (ntohs(ud->uh_ulen) - sizeof(struct udphdr) >= sizeof(struct cu_header)) { 86127094Sdes struct cu_header *cu; 87131614Sdes struct alias_link *cu_lnk; 8837131Sbrian 89131699Sdes cu = udp_next(ud); 90127094Sdes if (cu->addr) 91131614Sdes cu->addr = (u_int32_t) GetAliasAddress(lnk).s_addr; 9237131Sbrian 93131614Sdes cu_lnk = FindUdpTcpOut(la, pip->ip_src, GetDestAddress(lnk), 94127094Sdes ud->uh_dport, 0, IPPROTO_UDP, 1); 9599207Sbrian 9637131Sbrian#ifndef NO_FW_PUNCH 97131614Sdes if (cu_lnk) 98131614Sdes PunchFWHole(cu_lnk); 9937131Sbrian#endif 100127094Sdes } 10137131Sbrian} 10237131Sbrian 10337131Sbrianvoid 104124621SphkAliasHandleCUSeeMeIn(struct libalias *la, struct ip *pip, struct in_addr original_addr) 10537131Sbrian{ 106127094Sdes struct in_addr alias_addr; 107127094Sdes struct udphdr *ud; 108127094Sdes struct cu_header *cu; 109127094Sdes struct oc_header *oc; 110127094Sdes struct client_info *ci; 111127094Sdes char *end; 112127094Sdes int i; 11337131Sbrian 114131614Sdes (void)la; 115127094Sdes alias_addr.s_addr = pip->ip_dst.s_addr; 116131699Sdes ud = ip_next(pip); 117131699Sdes cu = udp_next(ud); 118127094Sdes oc = (struct oc_header *)(cu + 1); 119127094Sdes ci = (struct client_info *)(oc + 1); 120127094Sdes end = (char *)ud + ntohs(ud->uh_ulen); 12137131Sbrian 122127094Sdes if ((char *)oc <= end) { 123127094Sdes if (cu->dest_addr) 124127094Sdes cu->dest_addr = (u_int32_t) original_addr.s_addr; 125127094Sdes if (ntohs(cu->data_type) == 101) 126127094Sdes /* Find and change our address */ 127127094Sdes for (i = 0; (char *)(ci + 1) <= end && i < oc->client_count; i++, ci++) 128127094Sdes if (ci->address == (u_int32_t) alias_addr.s_addr) { 129127094Sdes ci->address = (u_int32_t) original_addr.s_addr; 130127094Sdes break; 131127094Sdes } 132127094Sdes } 13337131Sbrian} 134