NetBSD-5.0.2/sys/dist/ipf/netinet/ip_h323_pxy.c
/* $NetBSD: ip_h323_pxy.c,v 1.10 2008/05/20 07:08:07 darrenr Exp $ */
/*
* Copyright 2001, QNX Software Systems Ltd. All Rights Reserved
*
* This source code has been published by QNX Software Systems Ltd. (QSSL).
* However, any use, reproduction, modification, distribution or transfer of
* this software, or any software which includes or is based upon any of this
* code, is only permitted under the terms of the QNX Open Community License
* version 1.0 (see licensing.qnx.com for details) or as otherwise expressly
* authorized by a written license agreement from QSSL. For more information,
* please email licensing@qnx.com.
*
* For more details, see QNX_OCL.txt provided with this distribution.
*/
/*
* Simple H.323 proxy
*
* by xtang@canada.com
* ported to ipfilter 3.4.20 by Michael Grant mg-ipf@grant.org
*/
#if __FreeBSD_version >= 220000 && defined(_KERNEL)
# include <sys/fcntl.h>
# include <sys/filio.h>
#else
# ifndef linux
# include <sys/ioctl.h>
# endif
#endif
#ifdef _KERNEL_OPT
#include "opt_ipfilter.h"
#endif
#include <sys/cdefs.h>
__KERNEL_RCSID(1, "$NetBSD: ip_h323_pxy.c,v 1.10 2008/05/20 07:08:07 darrenr Exp $");
#define IPF_H323_PROXY
int ippr_h323_init __P((void));
void ippr_h323_fini __P((void));
int ippr_h323_new __P((fr_info_t *, ap_session_t *, nat_t *));
void ippr_h323_del __P((ap_session_t *));
int ippr_h323_out __P((fr_info_t *, ap_session_t *, nat_t *));
int ippr_h323_in __P((fr_info_t *, ap_session_t *, nat_t *));
int ippr_h245_new __P((fr_info_t *, ap_session_t *, nat_t *));
int ippr_h245_out __P((fr_info_t *, ap_session_t *, nat_t *));
int ippr_h245_in __P((fr_info_t *, ap_session_t *, nat_t *));
static frentry_t h323_fr;
int h323_proxy_init = 0;
static int find_port __P((int, void *, int datlen, int *, u_short *));
static int find_port(ipaddr, data, datlen, off, port)
int ipaddr;
void *data;
int datlen, *off;
unsigned short *port;
{
u_32_t addr, netaddr;
u_char *dp;
int offset;
if (datlen < 6)
return -1;
*port = 0;
offset = *off;
dp = (u_char *)data;
netaddr = ntohl(ipaddr);
for (offset = 0; offset <= datlen - 6; offset++, dp++) {
addr = (dp[0] << 24) | (dp[1] << 16) | (dp[2] << 8) | dp[3];
if (netaddr == addr)
{
*port = (*(dp + 4) << 8) | *(dp + 5);
break;
}
}
*off = offset;
return (offset > datlen - 6) ? -1 : 0;
}
/*
* Initialize local structures.
*/
int ippr_h323_init()
{
bzero((char *)&h323_fr, sizeof(h323_fr));
h323_fr.fr_ref = 1;
h323_fr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
MUTEX_INIT(&h323_fr.fr_lock, "H323 proxy rule lock");
h323_proxy_init = 1;
return 0;
}
void ippr_h323_fini()
{
if (h323_proxy_init == 1) {
MUTEX_DESTROY(&h323_fr.fr_lock);
h323_proxy_init = 0;
}
}
int ippr_h323_new(fin, aps, nat)
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
fin = fin; /* LINT */
nat = nat; /* LINT */
aps->aps_data = NULL;
aps->aps_psiz = 0;
return 0;
}
void ippr_h323_del(aps)
ap_session_t *aps;
{
int i;
ipnat_t *ipn;
if (aps->aps_data) {
for (i = 0, ipn = aps->aps_data;
i < (aps->aps_psiz / sizeof(ipnat_t));
i++, ipn = (ipnat_t *)((char *)ipn + sizeof(*ipn)))
{
/*
* Check the comment in ippr_h323_in() function,
* just above fr_nat_ioctl() call.
* We are lucky here because this function is not
* called with ipf_nat locked.
*/
if (fr_nat_ioctl((caddr_t)ipn, SIOCRMNAT, NAT_SYSSPACE|
NAT_LOCKHELD|FWRITE, 0, NULL) == -1) {
/*EMPTY*/;
/* log the error */
}
}
KFREES(aps->aps_data, aps->aps_psiz);
/* avoid double free */
aps->aps_data = NULL;
aps->aps_psiz = 0;
}
return;
}
int ippr_h323_in(fin, aps, nat)
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
int ipaddr, off, datlen;
unsigned short port;
tcphdr_t *tcp;
void *data;
ip_t *ip;
ip = fin->fin_ip;
tcp = (tcphdr_t *)fin->fin_dp;
ipaddr = ip->ip_src.s_addr;
data = (char *)tcp + (TCP_OFF(tcp) << 2);
datlen = fin->fin_dlen - (TCP_OFF(tcp) << 2);
if (find_port(ipaddr, data, datlen, &off, &port) == 0) {
ipnat_t *ipn;
char *newarray;
/* setup a nat rule to set a h245 proxy on tcp-port "port"
* it's like:
* map <if> <inter_ip>/<mask> -> <gate_ip>/<mask> proxy port <port> <port>/tcp
*/
KMALLOCS(newarray, char *, aps->aps_psiz + sizeof(*ipn));
if (newarray == NULL) {
return -1;
}
ipn = (ipnat_t *)&newarray[aps->aps_psiz];
bcopy((void *)nat->nat_ptr, (void *)ipn, sizeof(ipnat_t));
(void) strncpy(ipn->in_plabel, "h245", APR_LABELLEN);
ipn->in_inip = nat->nat_inip.s_addr;
ipn->in_inmsk = 0xffffffff;
ipn->in_dport = htons(port);
/*
* we got a problem here. we need to call fr_nat_ioctl() to add
* the h245 proxy rule, but since we already hold (READ locked)
* the nat table rwlock (ipf_nat), if we go into fr_nat_ioctl(),
* it will try to WRITE lock it. This will causing dead lock
* on RTP.
*
* The quick & dirty solution here is release the read lock,
* call fr_nat_ioctl() and re-lock it.
* A (maybe better) solution is do a UPGRADE(), and instead
* of calling fr_nat_ioctl(), we add the nat rule ourself.
*/
RWLOCK_EXIT(&ipf_nat);
if (fr_nat_ioctl((caddr_t)ipn, SIOCADNAT,
NAT_SYSSPACE|FWRITE, 0, NULL) == -1) {
READ_ENTER(&ipf_nat);
return -1;
}
READ_ENTER(&ipf_nat);
if (aps->aps_data != NULL && aps->aps_psiz > 0) {
bcopy(aps->aps_data, newarray, aps->aps_psiz);
KFREES(aps->aps_data, aps->aps_psiz);
}
aps->aps_data = newarray;
aps->aps_psiz += sizeof(*ipn);
}
return 0;
}
int ippr_h245_new(fin, aps, nat)
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
fin = fin; /* LINT */
nat = nat; /* LINT */
aps->aps_data = NULL;
aps->aps_psiz = 0;
return 0;
}
int ippr_h245_out(fin, aps, nat)
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
int ipaddr, off, datlen;
tcphdr_t *tcp;
u_short port;
void *data;
ip_t *ip;
aps = aps; /* LINT */
ip = fin->fin_ip;
tcp = (tcphdr_t *)fin->fin_dp;
ipaddr = nat->nat_inip.s_addr;
data = (char *)tcp + (TCP_OFF(tcp) << 2);
datlen = fin->fin_dlen - (TCP_OFF(tcp) << 2);
if (find_port(ipaddr, data, datlen, &off, &port) == 0) {
fr_info_t fi;
nat_t *nat2;
/* port = htons(port); */
nat2 = nat_outlookup(fin, IPN_UDP, IPPROTO_UDP,
ip->ip_src, ip->ip_dst);
if (nat2 == NULL) {
struct ip newip;
struct udphdr udp;
bcopy((void *)ip, (void *)&newip, sizeof(newip));
newip.ip_len = fin->fin_hlen + sizeof(udp);
newip.ip_p = IPPROTO_UDP;
newip.ip_src = nat->nat_inip;
bzero((char *)&udp, sizeof(udp));
udp.uh_sport = port;
memcpy(&fi, fin, sizeof(fi));
fi.fin_state = NULL;
fi.fin_nat = NULL;
fi.fin_fi.fi_p = IPPROTO_UDP;
fi.fin_data[0] = port;
fi.fin_data[1] = 0;
fi.fin_dp = (char *)&udp;
nat2 = nat_new(&fi, nat->nat_ptr, NULL,
NAT_SLAVE|IPN_UDP|SI_W_DPORT,
NAT_OUTBOUND);
if (nat2 != NULL) {
(void) nat_proto(&fi, nat2, IPN_UDP);
nat_update(&fi, nat2, nat2->nat_ptr);
nat2->nat_ptr->in_hits++;
#ifdef IPFILTER_LOG
nat_log(nat2, (u_int)(nat->nat_ptr->in_redir));
#endif
memcpy((char *)data + off, &ip->ip_src.s_addr, 4);
memcpy((char *)data + off + 4, &nat2->nat_outport, 2);
}
}
}
return 0;
}