301 lines
7.0 KiB
C
301 lines
7.0 KiB
C
/* $NetBSD: ip_h323_pxy.c,v 1.9 2004/03/28 09:00:57 martti Exp $ */
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/*
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* Copyright 2001, QNX Software Systems Ltd. All Rights Reserved
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*
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* This source code has been published by QNX Software Systems Ltd. (QSSL).
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* However, any use, reproduction, modification, distribution or transfer of
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* this software, or any software which includes or is based upon any of this
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* code, is only permitted under the terms of the QNX Open Community License
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* version 1.0 (see licensing.qnx.com for details) or as otherwise expressly
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* authorized by a written license agreement from QSSL. For more information,
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* please email licensing@qnx.com.
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*
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* For more details, see QNX_OCL.txt provided with this distribution.
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*/
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/*
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* Simple H.323 proxy
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*
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* by xtang@canada.com
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* ported to ipfilter 3.4.20 by Michael Grant mg-ipf@grant.org
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*/
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#if __FreeBSD_version >= 220000 && defined(_KERNEL)
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# include <sys/fcntl.h>
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# include <sys/filio.h>
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#else
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# include <sys/ioctl.h>
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#endif
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#ifdef _KERNEL_OPT
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#include "opt_ipfilter_log.h"
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#endif
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__KERNEL_RCSID(1, "$NetBSD: ip_h323_pxy.c,v 1.9 2004/03/28 09:00:57 martti Exp $");
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#define IPF_H323_PROXY
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int ippr_h323_init __P((void));
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void ippr_h323_fini __P((void));
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int ippr_h323_new __P((fr_info_t *, ap_session_t *, nat_t *));
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void ippr_h323_del __P((ap_session_t *));
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int ippr_h323_out __P((fr_info_t *, ap_session_t *, nat_t *));
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int ippr_h323_in __P((fr_info_t *, ap_session_t *, nat_t *));
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int ippr_h245_new __P((fr_info_t *, ap_session_t *, nat_t *));
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int ippr_h245_out __P((fr_info_t *, ap_session_t *, nat_t *));
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int ippr_h245_in __P((fr_info_t *, ap_session_t *, nat_t *));
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static frentry_t h323_fr;
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int h323_proxy_init = 0;
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static int find_port __P((int, caddr_t, int datlen, int *, u_short *));
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static int find_port(ipaddr, data, datlen, off, port)
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int ipaddr;
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caddr_t data;
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int datlen, *off;
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unsigned short *port;
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{
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u_32_t addr, netaddr;
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u_char *dp;
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int offset;
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if (datlen < 6)
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return -1;
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*port = 0;
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offset = *off;
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dp = (u_char *)data;
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netaddr = ntohl(ipaddr);
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for (offset = 0; offset <= datlen - 6; offset++, dp++) {
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addr = (dp[0] << 24) | (dp[1] << 16) | (dp[2] << 8) | dp[3];
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if (netaddr == addr)
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{
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*port = (*(dp + 4) << 8) | *(dp + 5);
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break;
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}
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}
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*off = offset;
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return (offset > datlen - 6) ? -1 : 0;
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}
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/*
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* Initialize local structures.
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*/
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int ippr_h323_init()
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{
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bzero((char *)&h323_fr, sizeof(h323_fr));
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h323_fr.fr_ref = 1;
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h323_fr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
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MUTEX_INIT(&h323_fr.fr_lock, "H323 proxy rule lock");
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h323_proxy_init = 1;
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return 0;
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}
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void ippr_h323_fini()
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{
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if (h323_proxy_init == 1) {
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MUTEX_DESTROY(&h323_fr.fr_lock);
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h323_proxy_init = 0;
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}
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}
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int ippr_h323_new(fin, aps, nat)
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fr_info_t *fin;
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ap_session_t *aps;
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nat_t *nat;
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{
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fin = fin; /* LINT */
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nat = nat; /* LINT */
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aps->aps_data = NULL;
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aps->aps_psiz = 0;
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return 0;
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}
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void ippr_h323_del(aps)
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ap_session_t *aps;
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{
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int i;
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ipnat_t *ipn;
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if (aps->aps_data) {
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for (i = 0, ipn = aps->aps_data;
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i < (aps->aps_psiz / sizeof(ipnat_t));
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i++, ipn = (ipnat_t *)((char *)ipn + sizeof(*ipn)))
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{
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/*
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* Check the comment in ippr_h323_in() function,
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* just above fr_nat_ioctl() call.
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* We are lucky here because this function is not
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* called with ipf_nat locked.
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*/
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if (fr_nat_ioctl((caddr_t)ipn, SIOCRMNAT, NAT_SYSSPACE|
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NAT_LOCKHELD|FWRITE) == -1) {
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/*EMPTY*/;
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/* log the error */
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}
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}
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KFREES(aps->aps_data, aps->aps_psiz);
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/* avoid double free */
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aps->aps_data = NULL;
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aps->aps_psiz = 0;
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}
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return;
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}
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int ippr_h323_in(fin, aps, nat)
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fr_info_t *fin;
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ap_session_t *aps;
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nat_t *nat;
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{
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int ipaddr, off, datlen;
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unsigned short port;
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caddr_t data;
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tcphdr_t *tcp;
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ip_t *ip;
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ip = fin->fin_ip;
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tcp = (tcphdr_t *)fin->fin_dp;
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ipaddr = ip->ip_src.s_addr;
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data = (caddr_t)tcp + (TCP_OFF(tcp) << 2);
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datlen = fin->fin_dlen - (TCP_OFF(tcp) << 2);
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if (find_port(ipaddr, data, datlen, &off, &port) == 0) {
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ipnat_t *ipn;
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char *newarray;
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/* setup a nat rule to set a h245 proxy on tcp-port "port"
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* it's like:
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* map <if> <inter_ip>/<mask> -> <gate_ip>/<mask> proxy port <port> <port>/tcp
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*/
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KMALLOCS(newarray, char *, aps->aps_psiz + sizeof(*ipn));
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if (newarray == NULL) {
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return -1;
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}
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ipn = (ipnat_t *)&newarray[aps->aps_psiz];
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bcopy((caddr_t)nat->nat_ptr, (caddr_t)ipn, sizeof(ipnat_t));
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(void) strncpy(ipn->in_plabel, "h245", APR_LABELLEN);
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ipn->in_inip = nat->nat_inip.s_addr;
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ipn->in_inmsk = 0xffffffff;
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ipn->in_dport = htons(port);
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/*
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* we got a problem here. we need to call fr_nat_ioctl() to add
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* the h245 proxy rule, but since we already hold (READ locked)
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* the nat table rwlock (ipf_nat), if we go into fr_nat_ioctl(),
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* it will try to WRITE lock it. This will causing dead lock
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* on RTP.
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*
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* The quick & dirty solution here is release the read lock,
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* call fr_nat_ioctl() and re-lock it.
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* A (maybe better) solution is do a UPGRADE(), and instead
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* of calling fr_nat_ioctl(), we add the nat rule ourself.
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*/
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RWLOCK_EXIT(&ipf_nat);
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if (fr_nat_ioctl((caddr_t)ipn, SIOCADNAT,
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NAT_SYSSPACE|FWRITE) == -1) {
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READ_ENTER(&ipf_nat);
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return -1;
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}
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READ_ENTER(&ipf_nat);
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if (aps->aps_data != NULL && aps->aps_psiz > 0) {
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bcopy(aps->aps_data, newarray, aps->aps_psiz);
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KFREES(aps->aps_data, aps->aps_psiz);
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}
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aps->aps_data = newarray;
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aps->aps_psiz += sizeof(*ipn);
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}
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return 0;
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}
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int ippr_h245_new(fin, aps, nat)
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fr_info_t *fin;
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ap_session_t *aps;
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nat_t *nat;
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{
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fin = fin; /* LINT */
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nat = nat; /* LINT */
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aps->aps_data = NULL;
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aps->aps_psiz = 0;
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return 0;
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}
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int ippr_h245_out(fin, aps, nat)
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fr_info_t *fin;
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ap_session_t *aps;
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nat_t *nat;
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{
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int ipaddr, off, datlen;
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tcphdr_t *tcp;
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caddr_t data;
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u_short port;
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ip_t *ip;
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aps = aps; /* LINT */
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ip = fin->fin_ip;
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tcp = (tcphdr_t *)fin->fin_dp;
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ipaddr = nat->nat_inip.s_addr;
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data = (caddr_t)tcp + (TCP_OFF(tcp) << 2);
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datlen = ip->ip_len - fin->fin_hlen - (TCP_OFF(tcp) << 2);
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if (find_port(ipaddr, data, datlen, &off, &port) == 0) {
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fr_info_t fi;
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nat_t *nat2;
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/* port = htons(port); */
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nat2 = nat_outlookup(fin->fin_ifp, IPN_UDP, IPPROTO_UDP,
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ip->ip_src, ip->ip_dst);
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if (nat2 == NULL) {
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struct ip newip;
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struct udphdr udp;
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bcopy((caddr_t)ip, (caddr_t)&newip, sizeof(newip));
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newip.ip_len = fin->fin_hlen + sizeof(udp);
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newip.ip_p = IPPROTO_UDP;
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newip.ip_src = nat->nat_inip;
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bzero((char *)&udp, sizeof(udp));
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udp.uh_sport = port;
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bcopy((caddr_t)fin, (caddr_t)&fi, sizeof(fi));
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fi.fin_fi.fi_p = IPPROTO_UDP;
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fi.fin_data[0] = port;
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fi.fin_data[1] = 0;
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fi.fin_dp = (char *)&udp;
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nat2 = nat_new(&fi, nat->nat_ptr, NULL,
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NAT_SLAVE|IPN_UDP|SI_W_DPORT,
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NAT_OUTBOUND);
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if (nat2 != NULL) {
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(void) nat_proto(&fi, nat2, IPN_UDP);
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nat_update(&fi, nat2, nat2->nat_ptr);
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nat2->nat_ptr->in_hits++;
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#ifdef IPFILTER_LOG
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nat_log(nat2, (u_int)(nat->nat_ptr->in_redir));
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#endif
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bcopy((caddr_t)&ip->ip_src.s_addr,
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data + off, 4);
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bcopy((caddr_t)&nat2->nat_outport,
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data + off + 4, 2);
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}
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}
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}
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return 0;
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}
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