121 lines
3.7 KiB
C
121 lines
3.7 KiB
C
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/*-
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* Copyright (c) 1998 Brian Somers <brian@Awfulhak.org>
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* with the aid of code written by
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* Junichi SATOH <junichi@astec.co.jp> 1996, 1997.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $Id$
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*/
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#include <sys/types.h>
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#include <netinet/in_systm.h>
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#include <netinet/in.h>
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#include <netinet/ip.h>
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#include <netinet/udp.h>
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#include "alias_local.h"
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/* CU-SeeMe Data Header */
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struct cu_header {
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u_int16_t dest_family;
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u_int16_t dest_port;
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u_int32_t dest_addr;
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int16_t family;
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u_int16_t port;
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u_int32_t addr;
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u_int32_t seq;
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u_int16_t msg;
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u_int16_t data_type;
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u_int16_t packet_len;
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};
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/* Open Continue Header */
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struct oc_header {
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u_int16_t client_count; /* Number of client info structs */
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u_int32_t seq_no;
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char user_name[20];
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char reserved[4]; /* flags, version stuff, etc */
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};
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/* client info structures */
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struct client_info {
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u_int32_t address; /* Client address */
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char reserved[8]; /* Flags, pruning bitfield, packet counts etc */
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};
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void
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AliasHandleCUSeeMeOut(struct ip *pip, struct alias_link *link)
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{
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struct udphdr *ud;
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ud = (struct udphdr *)((char *)pip + (pip->ip_hl << 2));
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if(ud->uh_ulen >= sizeof(struct cu_header)) {
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struct cu_header *cu;
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struct alias_link *cu_link;
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cu = (struct cu_header *)(ud + 1);
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if (cu->addr)
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cu->addr = (u_int32_t)GetAliasAddress(link).s_addr;
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cu_link = FindUdpTcpOut(pip->ip_src, GetDestAddress(link),
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ud->uh_dport, 0, IPPROTO_UDP);
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#ifndef NO_FW_PUNCH
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if (cu_link)
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PunchFWHole(cu_link);
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#endif
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}
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}
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void
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AliasHandleCUSeeMeIn(struct ip *pip, struct in_addr original_addr)
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{
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struct in_addr alias_addr;
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struct udphdr *ud;
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struct cu_header *cu;
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struct oc_header *oc;
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struct client_info *ci;
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char *end;
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int i;
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alias_addr.s_addr = pip->ip_dst.s_addr;
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ud = (struct udphdr *)((char *)pip + (pip->ip_hl << 2));
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cu = (struct cu_header *)(ud + 1);
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oc = (struct oc_header *)(cu + 1);
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ci = (struct client_info *)(oc + 1);
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end = (char *)cu + ud->uh_ulen;
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if ((char *)oc <= end) {
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if(cu->dest_addr)
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cu->dest_addr = (u_int32_t)original_addr.s_addr;
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if(ntohs(cu->data_type) == 101)
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/* Find and change our address */
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for(i = 0; (char *)(ci + 1) <= end && i < oc->client_count; i++, ci++)
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if(ci->address == (u_int32_t)alias_addr.s_addr) {
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ci->address = (u_int32_t)original_addr.s_addr;
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break;
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}
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}
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}
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