// SPDX-License-Identifier: GPL-2.0-only
|
/*
|
* H.323 connection tracking helper
|
*
|
* Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net>
|
* Copyright (c) 2006-2012 Patrick McHardy <kaber@trash.net>
|
*
|
* Based on the 'brute force' H.323 connection tracking module by
|
* Jozsef Kadlecsik <kadlec@netfilter.org>
|
*
|
* For more information, please see http://nath323.sourceforge.net/
|
*/
|
|
#include <linux/module.h>
|
#include <linux/moduleparam.h>
|
#include <linux/ctype.h>
|
#include <linux/inet.h>
|
#include <linux/in.h>
|
#include <linux/ip.h>
|
#include <linux/slab.h>
|
#include <linux/udp.h>
|
#include <linux/tcp.h>
|
#include <linux/skbuff.h>
|
#include <net/route.h>
|
#include <net/ip6_route.h>
|
#include <linux/netfilter_ipv6.h>
|
|
#include <net/netfilter/nf_conntrack.h>
|
#include <net/netfilter/nf_conntrack_core.h>
|
#include <net/netfilter/nf_conntrack_tuple.h>
|
#include <net/netfilter/nf_conntrack_expect.h>
|
#include <net/netfilter/nf_conntrack_ecache.h>
|
#include <net/netfilter/nf_conntrack_helper.h>
|
#include <net/netfilter/nf_conntrack_zones.h>
|
#include <linux/netfilter/nf_conntrack_h323.h>
|
|
/* Parameters */
|
static unsigned int default_rrq_ttl __read_mostly = 300;
|
module_param(default_rrq_ttl, uint, 0600);
|
MODULE_PARM_DESC(default_rrq_ttl, "use this TTL if it's missing in RRQ");
|
|
static int gkrouted_only __read_mostly = 1;
|
module_param(gkrouted_only, int, 0600);
|
MODULE_PARM_DESC(gkrouted_only, "only accept calls from gatekeeper");
|
|
static bool callforward_filter __read_mostly = true;
|
module_param(callforward_filter, bool, 0600);
|
MODULE_PARM_DESC(callforward_filter, "only create call forwarding expectations "
|
"if both endpoints are on different sides "
|
"(determined by routing information)");
|
|
/* Hooks for NAT */
|
int (*set_h245_addr_hook) (struct sk_buff *skb, unsigned int protoff,
|
unsigned char **data, int dataoff,
|
H245_TransportAddress *taddr,
|
union nf_inet_addr *addr, __be16 port)
|
__read_mostly;
|
int (*set_h225_addr_hook) (struct sk_buff *skb, unsigned int protoff,
|
unsigned char **data, int dataoff,
|
TransportAddress *taddr,
|
union nf_inet_addr *addr, __be16 port)
|
__read_mostly;
|
int (*set_sig_addr_hook) (struct sk_buff *skb,
|
struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff, unsigned char **data,
|
TransportAddress *taddr, int count) __read_mostly;
|
int (*set_ras_addr_hook) (struct sk_buff *skb,
|
struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff, unsigned char **data,
|
TransportAddress *taddr, int count) __read_mostly;
|
int (*nat_rtp_rtcp_hook) (struct sk_buff *skb,
|
struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, int dataoff,
|
H245_TransportAddress *taddr,
|
__be16 port, __be16 rtp_port,
|
struct nf_conntrack_expect *rtp_exp,
|
struct nf_conntrack_expect *rtcp_exp) __read_mostly;
|
int (*nat_t120_hook) (struct sk_buff *skb,
|
struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, int dataoff,
|
H245_TransportAddress *taddr, __be16 port,
|
struct nf_conntrack_expect *exp) __read_mostly;
|
int (*nat_h245_hook) (struct sk_buff *skb,
|
struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, int dataoff,
|
TransportAddress *taddr, __be16 port,
|
struct nf_conntrack_expect *exp) __read_mostly;
|
int (*nat_callforwarding_hook) (struct sk_buff *skb,
|
struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, int dataoff,
|
TransportAddress *taddr, __be16 port,
|
struct nf_conntrack_expect *exp) __read_mostly;
|
int (*nat_q931_hook) (struct sk_buff *skb,
|
struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, TransportAddress *taddr, int idx,
|
__be16 port, struct nf_conntrack_expect *exp)
|
__read_mostly;
|
|
static DEFINE_SPINLOCK(nf_h323_lock);
|
static char *h323_buffer;
|
|
static struct nf_conntrack_helper nf_conntrack_helper_h245;
|
static struct nf_conntrack_helper nf_conntrack_helper_q931[];
|
static struct nf_conntrack_helper nf_conntrack_helper_ras[];
|
|
static int get_tpkt_data(struct sk_buff *skb, unsigned int protoff,
|
struct nf_conn *ct, enum ip_conntrack_info ctinfo,
|
unsigned char **data, int *datalen, int *dataoff)
|
{
|
struct nf_ct_h323_master *info = nfct_help_data(ct);
|
int dir = CTINFO2DIR(ctinfo);
|
const struct tcphdr *th;
|
struct tcphdr _tcph;
|
int tcpdatalen;
|
int tcpdataoff;
|
unsigned char *tpkt;
|
int tpktlen;
|
int tpktoff;
|
|
/* Get TCP header */
|
th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph);
|
if (th == NULL)
|
return 0;
|
|
/* Get TCP data offset */
|
tcpdataoff = protoff + th->doff * 4;
|
|
/* Get TCP data length */
|
tcpdatalen = skb->len - tcpdataoff;
|
if (tcpdatalen <= 0) /* No TCP data */
|
goto clear_out;
|
|
if (*data == NULL) { /* first TPKT */
|
/* Get first TPKT pointer */
|
tpkt = skb_header_pointer(skb, tcpdataoff, tcpdatalen,
|
h323_buffer);
|
BUG_ON(tpkt == NULL);
|
|
/* Validate TPKT identifier */
|
if (tcpdatalen < 4 || tpkt[0] != 0x03 || tpkt[1] != 0) {
|
/* Netmeeting sends TPKT header and data separately */
|
if (info->tpkt_len[dir] > 0) {
|
pr_debug("nf_ct_h323: previous packet "
|
"indicated separate TPKT data of %hu "
|
"bytes\n", info->tpkt_len[dir]);
|
if (info->tpkt_len[dir] <= tcpdatalen) {
|
/* Yes, there was a TPKT header
|
* received */
|
*data = tpkt;
|
*datalen = info->tpkt_len[dir];
|
*dataoff = 0;
|
goto out;
|
}
|
|
/* Fragmented TPKT */
|
pr_debug("nf_ct_h323: fragmented TPKT\n");
|
goto clear_out;
|
}
|
|
/* It is not even a TPKT */
|
return 0;
|
}
|
tpktoff = 0;
|
} else { /* Next TPKT */
|
tpktoff = *dataoff + *datalen;
|
tcpdatalen -= tpktoff;
|
if (tcpdatalen <= 4) /* No more TPKT */
|
goto clear_out;
|
tpkt = *data + *datalen;
|
|
/* Validate TPKT identifier */
|
if (tpkt[0] != 0x03 || tpkt[1] != 0)
|
goto clear_out;
|
}
|
|
/* Validate TPKT length */
|
tpktlen = tpkt[2] * 256 + tpkt[3];
|
if (tpktlen < 4)
|
goto clear_out;
|
if (tpktlen > tcpdatalen) {
|
if (tcpdatalen == 4) { /* Separate TPKT header */
|
/* Netmeeting sends TPKT header and data separately */
|
pr_debug("nf_ct_h323: separate TPKT header indicates "
|
"there will be TPKT data of %hu bytes\n",
|
tpktlen - 4);
|
info->tpkt_len[dir] = tpktlen - 4;
|
return 0;
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}
|
|
pr_debug("nf_ct_h323: incomplete TPKT (fragmented?)\n");
|
goto clear_out;
|
}
|
|
/* This is the encapsulated data */
|
*data = tpkt + 4;
|
*datalen = tpktlen - 4;
|
*dataoff = tpktoff + 4;
|
|
out:
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/* Clear TPKT length */
|
info->tpkt_len[dir] = 0;
|
return 1;
|
|
clear_out:
|
info->tpkt_len[dir] = 0;
|
return 0;
|
}
|
|
static int get_h245_addr(struct nf_conn *ct, const unsigned char *data,
|
H245_TransportAddress *taddr,
|
union nf_inet_addr *addr, __be16 *port)
|
{
|
const unsigned char *p;
|
int len;
|
|
if (taddr->choice != eH245_TransportAddress_unicastAddress)
|
return 0;
|
|
switch (taddr->unicastAddress.choice) {
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case eUnicastAddress_iPAddress:
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if (nf_ct_l3num(ct) != AF_INET)
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return 0;
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p = data + taddr->unicastAddress.iPAddress.network;
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len = 4;
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break;
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case eUnicastAddress_iP6Address:
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if (nf_ct_l3num(ct) != AF_INET6)
|
return 0;
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p = data + taddr->unicastAddress.iP6Address.network;
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len = 16;
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break;
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default:
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return 0;
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}
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memcpy(addr, p, len);
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memset((void *)addr + len, 0, sizeof(*addr) - len);
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memcpy(port, p + len, sizeof(__be16));
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return 1;
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}
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static int expect_rtp_rtcp(struct sk_buff *skb, struct nf_conn *ct,
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enum ip_conntrack_info ctinfo,
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unsigned int protoff,
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unsigned char **data, int dataoff,
|
H245_TransportAddress *taddr)
|
{
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int dir = CTINFO2DIR(ctinfo);
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int ret = 0;
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__be16 port;
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__be16 rtp_port, rtcp_port;
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union nf_inet_addr addr;
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struct nf_conntrack_expect *rtp_exp;
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struct nf_conntrack_expect *rtcp_exp;
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typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp;
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/* Read RTP or RTCP address */
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if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
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memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
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port == 0)
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return 0;
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/* RTP port is even */
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rtp_port = port & ~htons(1);
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rtcp_port = port | htons(1);
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/* Create expect for RTP */
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if ((rtp_exp = nf_ct_expect_alloc(ct)) == NULL)
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return -1;
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nf_ct_expect_init(rtp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
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&ct->tuplehash[!dir].tuple.src.u3,
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&ct->tuplehash[!dir].tuple.dst.u3,
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IPPROTO_UDP, NULL, &rtp_port);
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/* Create expect for RTCP */
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if ((rtcp_exp = nf_ct_expect_alloc(ct)) == NULL) {
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nf_ct_expect_put(rtp_exp);
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return -1;
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}
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nf_ct_expect_init(rtcp_exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
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&ct->tuplehash[!dir].tuple.src.u3,
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&ct->tuplehash[!dir].tuple.dst.u3,
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IPPROTO_UDP, NULL, &rtcp_port);
|
|
if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
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&ct->tuplehash[!dir].tuple.dst.u3,
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sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
|
(nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) &&
|
nf_ct_l3num(ct) == NFPROTO_IPV4 &&
|
ct->status & IPS_NAT_MASK) {
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/* NAT needed */
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ret = nat_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
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taddr, port, rtp_port, rtp_exp, rtcp_exp);
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} else { /* Conntrack only */
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if (nf_ct_expect_related(rtp_exp, 0) == 0) {
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if (nf_ct_expect_related(rtcp_exp, 0) == 0) {
|
pr_debug("nf_ct_h323: expect RTP ");
|
nf_ct_dump_tuple(&rtp_exp->tuple);
|
pr_debug("nf_ct_h323: expect RTCP ");
|
nf_ct_dump_tuple(&rtcp_exp->tuple);
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} else {
|
nf_ct_unexpect_related(rtp_exp);
|
ret = -1;
|
}
|
} else
|
ret = -1;
|
}
|
|
nf_ct_expect_put(rtp_exp);
|
nf_ct_expect_put(rtcp_exp);
|
|
return ret;
|
}
|
|
static int expect_t120(struct sk_buff *skb,
|
struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, int dataoff,
|
H245_TransportAddress *taddr)
|
{
|
int dir = CTINFO2DIR(ctinfo);
|
int ret = 0;
|
__be16 port;
|
union nf_inet_addr addr;
|
struct nf_conntrack_expect *exp;
|
typeof(nat_t120_hook) nat_t120;
|
|
/* Read T.120 address */
|
if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
|
memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
|
port == 0)
|
return 0;
|
|
/* Create expect for T.120 connections */
|
if ((exp = nf_ct_expect_alloc(ct)) == NULL)
|
return -1;
|
nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
|
&ct->tuplehash[!dir].tuple.src.u3,
|
&ct->tuplehash[!dir].tuple.dst.u3,
|
IPPROTO_TCP, NULL, &port);
|
exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple channels */
|
|
if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
|
&ct->tuplehash[!dir].tuple.dst.u3,
|
sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
|
(nat_t120 = rcu_dereference(nat_t120_hook)) &&
|
nf_ct_l3num(ct) == NFPROTO_IPV4 &&
|
ct->status & IPS_NAT_MASK) {
|
/* NAT needed */
|
ret = nat_t120(skb, ct, ctinfo, protoff, data, dataoff, taddr,
|
port, exp);
|
} else { /* Conntrack only */
|
if (nf_ct_expect_related(exp, 0) == 0) {
|
pr_debug("nf_ct_h323: expect T.120 ");
|
nf_ct_dump_tuple(&exp->tuple);
|
} else
|
ret = -1;
|
}
|
|
nf_ct_expect_put(exp);
|
|
return ret;
|
}
|
|
static int process_h245_channel(struct sk_buff *skb,
|
struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, int dataoff,
|
H2250LogicalChannelParameters *channel)
|
{
|
int ret;
|
|
if (channel->options & eH2250LogicalChannelParameters_mediaChannel) {
|
/* RTP */
|
ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
|
&channel->mediaChannel);
|
if (ret < 0)
|
return -1;
|
}
|
|
if (channel->
|
options & eH2250LogicalChannelParameters_mediaControlChannel) {
|
/* RTCP */
|
ret = expect_rtp_rtcp(skb, ct, ctinfo, protoff, data, dataoff,
|
&channel->mediaControlChannel);
|
if (ret < 0)
|
return -1;
|
}
|
|
return 0;
|
}
|
|
static int process_olc(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, int dataoff,
|
OpenLogicalChannel *olc)
|
{
|
int ret;
|
|
pr_debug("nf_ct_h323: OpenLogicalChannel\n");
|
|
if (olc->forwardLogicalChannelParameters.multiplexParameters.choice ==
|
eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)
|
{
|
ret = process_h245_channel(skb, ct, ctinfo,
|
protoff, data, dataoff,
|
&olc->
|
forwardLogicalChannelParameters.
|
multiplexParameters.
|
h2250LogicalChannelParameters);
|
if (ret < 0)
|
return -1;
|
}
|
|
if ((olc->options &
|
eOpenLogicalChannel_reverseLogicalChannelParameters) &&
|
(olc->reverseLogicalChannelParameters.options &
|
eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters)
|
&& (olc->reverseLogicalChannelParameters.multiplexParameters.
|
choice ==
|
eOpenLogicalChannel_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
|
{
|
ret =
|
process_h245_channel(skb, ct, ctinfo,
|
protoff, data, dataoff,
|
&olc->
|
reverseLogicalChannelParameters.
|
multiplexParameters.
|
h2250LogicalChannelParameters);
|
if (ret < 0)
|
return -1;
|
}
|
|
if ((olc->options & eOpenLogicalChannel_separateStack) &&
|
olc->forwardLogicalChannelParameters.dataType.choice ==
|
eDataType_data &&
|
olc->forwardLogicalChannelParameters.dataType.data.application.
|
choice == eDataApplicationCapability_application_t120 &&
|
olc->forwardLogicalChannelParameters.dataType.data.application.
|
t120.choice == eDataProtocolCapability_separateLANStack &&
|
olc->separateStack.networkAddress.choice ==
|
eNetworkAccessParameters_networkAddress_localAreaAddress) {
|
ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff,
|
&olc->separateStack.networkAddress.
|
localAreaAddress);
|
if (ret < 0)
|
return -1;
|
}
|
|
return 0;
|
}
|
|
static int process_olca(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff, unsigned char **data, int dataoff,
|
OpenLogicalChannelAck *olca)
|
{
|
H2250LogicalChannelAckParameters *ack;
|
int ret;
|
|
pr_debug("nf_ct_h323: OpenLogicalChannelAck\n");
|
|
if ((olca->options &
|
eOpenLogicalChannelAck_reverseLogicalChannelParameters) &&
|
(olca->reverseLogicalChannelParameters.options &
|
eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters)
|
&& (olca->reverseLogicalChannelParameters.multiplexParameters.
|
choice ==
|
eOpenLogicalChannelAck_reverseLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters))
|
{
|
ret = process_h245_channel(skb, ct, ctinfo,
|
protoff, data, dataoff,
|
&olca->
|
reverseLogicalChannelParameters.
|
multiplexParameters.
|
h2250LogicalChannelParameters);
|
if (ret < 0)
|
return -1;
|
}
|
|
if ((olca->options &
|
eOpenLogicalChannelAck_forwardMultiplexAckParameters) &&
|
(olca->forwardMultiplexAckParameters.choice ==
|
eOpenLogicalChannelAck_forwardMultiplexAckParameters_h2250LogicalChannelAckParameters))
|
{
|
ack = &olca->forwardMultiplexAckParameters.
|
h2250LogicalChannelAckParameters;
|
if (ack->options &
|
eH2250LogicalChannelAckParameters_mediaChannel) {
|
/* RTP */
|
ret = expect_rtp_rtcp(skb, ct, ctinfo,
|
protoff, data, dataoff,
|
&ack->mediaChannel);
|
if (ret < 0)
|
return -1;
|
}
|
|
if (ack->options &
|
eH2250LogicalChannelAckParameters_mediaControlChannel) {
|
/* RTCP */
|
ret = expect_rtp_rtcp(skb, ct, ctinfo,
|
protoff, data, dataoff,
|
&ack->mediaControlChannel);
|
if (ret < 0)
|
return -1;
|
}
|
}
|
|
if ((olca->options & eOpenLogicalChannelAck_separateStack) &&
|
olca->separateStack.networkAddress.choice ==
|
eNetworkAccessParameters_networkAddress_localAreaAddress) {
|
ret = expect_t120(skb, ct, ctinfo, protoff, data, dataoff,
|
&olca->separateStack.networkAddress.
|
localAreaAddress);
|
if (ret < 0)
|
return -1;
|
}
|
|
return 0;
|
}
|
|
static int process_h245(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff, unsigned char **data, int dataoff,
|
MultimediaSystemControlMessage *mscm)
|
{
|
switch (mscm->choice) {
|
case eMultimediaSystemControlMessage_request:
|
if (mscm->request.choice ==
|
eRequestMessage_openLogicalChannel) {
|
return process_olc(skb, ct, ctinfo,
|
protoff, data, dataoff,
|
&mscm->request.openLogicalChannel);
|
}
|
pr_debug("nf_ct_h323: H.245 Request %d\n",
|
mscm->request.choice);
|
break;
|
case eMultimediaSystemControlMessage_response:
|
if (mscm->response.choice ==
|
eResponseMessage_openLogicalChannelAck) {
|
return process_olca(skb, ct, ctinfo,
|
protoff, data, dataoff,
|
&mscm->response.
|
openLogicalChannelAck);
|
}
|
pr_debug("nf_ct_h323: H.245 Response %d\n",
|
mscm->response.choice);
|
break;
|
default:
|
pr_debug("nf_ct_h323: H.245 signal %d\n", mscm->choice);
|
break;
|
}
|
|
return 0;
|
}
|
|
static int h245_help(struct sk_buff *skb, unsigned int protoff,
|
struct nf_conn *ct, enum ip_conntrack_info ctinfo)
|
{
|
static MultimediaSystemControlMessage mscm;
|
unsigned char *data = NULL;
|
int datalen;
|
int dataoff;
|
int ret;
|
|
/* Until there's been traffic both ways, don't look in packets. */
|
if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
|
return NF_ACCEPT;
|
|
pr_debug("nf_ct_h245: skblen = %u\n", skb->len);
|
|
spin_lock_bh(&nf_h323_lock);
|
|
/* Process each TPKT */
|
while (get_tpkt_data(skb, protoff, ct, ctinfo,
|
&data, &datalen, &dataoff)) {
|
pr_debug("nf_ct_h245: TPKT len=%d ", datalen);
|
nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
|
|
/* Decode H.245 signal */
|
ret = DecodeMultimediaSystemControlMessage(data, datalen,
|
&mscm);
|
if (ret < 0) {
|
pr_debug("nf_ct_h245: decoding error: %s\n",
|
ret == H323_ERROR_BOUND ?
|
"out of bound" : "out of range");
|
/* We don't drop when decoding error */
|
break;
|
}
|
|
/* Process H.245 signal */
|
if (process_h245(skb, ct, ctinfo, protoff,
|
&data, dataoff, &mscm) < 0)
|
goto drop;
|
}
|
|
spin_unlock_bh(&nf_h323_lock);
|
return NF_ACCEPT;
|
|
drop:
|
spin_unlock_bh(&nf_h323_lock);
|
nf_ct_helper_log(skb, ct, "cannot process H.245 message");
|
return NF_DROP;
|
}
|
|
static const struct nf_conntrack_expect_policy h245_exp_policy = {
|
.max_expected = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
|
.timeout = 240,
|
};
|
|
static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
|
.name = "H.245",
|
.me = THIS_MODULE,
|
.tuple.src.l3num = AF_UNSPEC,
|
.tuple.dst.protonum = IPPROTO_UDP,
|
.help = h245_help,
|
.expect_policy = &h245_exp_policy,
|
};
|
|
int get_h225_addr(struct nf_conn *ct, unsigned char *data,
|
TransportAddress *taddr,
|
union nf_inet_addr *addr, __be16 *port)
|
{
|
const unsigned char *p;
|
int len;
|
|
switch (taddr->choice) {
|
case eTransportAddress_ipAddress:
|
if (nf_ct_l3num(ct) != AF_INET)
|
return 0;
|
p = data + taddr->ipAddress.ip;
|
len = 4;
|
break;
|
case eTransportAddress_ip6Address:
|
if (nf_ct_l3num(ct) != AF_INET6)
|
return 0;
|
p = data + taddr->ip6Address.ip;
|
len = 16;
|
break;
|
default:
|
return 0;
|
}
|
|
memcpy(addr, p, len);
|
memset((void *)addr + len, 0, sizeof(*addr) - len);
|
memcpy(port, p + len, sizeof(__be16));
|
|
return 1;
|
}
|
|
static int expect_h245(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff, unsigned char **data, int dataoff,
|
TransportAddress *taddr)
|
{
|
int dir = CTINFO2DIR(ctinfo);
|
int ret = 0;
|
__be16 port;
|
union nf_inet_addr addr;
|
struct nf_conntrack_expect *exp;
|
typeof(nat_h245_hook) nat_h245;
|
|
/* Read h245Address */
|
if (!get_h225_addr(ct, *data, taddr, &addr, &port) ||
|
memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
|
port == 0)
|
return 0;
|
|
/* Create expect for h245 connection */
|
if ((exp = nf_ct_expect_alloc(ct)) == NULL)
|
return -1;
|
nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
|
&ct->tuplehash[!dir].tuple.src.u3,
|
&ct->tuplehash[!dir].tuple.dst.u3,
|
IPPROTO_TCP, NULL, &port);
|
exp->helper = &nf_conntrack_helper_h245;
|
|
if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
|
&ct->tuplehash[!dir].tuple.dst.u3,
|
sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
|
(nat_h245 = rcu_dereference(nat_h245_hook)) &&
|
nf_ct_l3num(ct) == NFPROTO_IPV4 &&
|
ct->status & IPS_NAT_MASK) {
|
/* NAT needed */
|
ret = nat_h245(skb, ct, ctinfo, protoff, data, dataoff, taddr,
|
port, exp);
|
} else { /* Conntrack only */
|
if (nf_ct_expect_related(exp, 0) == 0) {
|
pr_debug("nf_ct_q931: expect H.245 ");
|
nf_ct_dump_tuple(&exp->tuple);
|
} else
|
ret = -1;
|
}
|
|
nf_ct_expect_put(exp);
|
|
return ret;
|
}
|
|
/* If the calling party is on the same side of the forward-to party,
|
* we don't need to track the second call
|
*/
|
static int callforward_do_filter(struct net *net,
|
const union nf_inet_addr *src,
|
const union nf_inet_addr *dst,
|
u_int8_t family)
|
{
|
int ret = 0;
|
|
switch (family) {
|
case AF_INET: {
|
struct flowi4 fl1, fl2;
|
struct rtable *rt1, *rt2;
|
|
memset(&fl1, 0, sizeof(fl1));
|
fl1.daddr = src->ip;
|
|
memset(&fl2, 0, sizeof(fl2));
|
fl2.daddr = dst->ip;
|
if (!nf_ip_route(net, (struct dst_entry **)&rt1,
|
flowi4_to_flowi(&fl1), false)) {
|
if (!nf_ip_route(net, (struct dst_entry **)&rt2,
|
flowi4_to_flowi(&fl2), false)) {
|
if (rt_nexthop(rt1, fl1.daddr) ==
|
rt_nexthop(rt2, fl2.daddr) &&
|
rt1->dst.dev == rt2->dst.dev)
|
ret = 1;
|
dst_release(&rt2->dst);
|
}
|
dst_release(&rt1->dst);
|
}
|
break;
|
}
|
#if IS_ENABLED(CONFIG_IPV6)
|
case AF_INET6: {
|
struct rt6_info *rt1, *rt2;
|
struct flowi6 fl1, fl2;
|
|
memset(&fl1, 0, sizeof(fl1));
|
fl1.daddr = src->in6;
|
|
memset(&fl2, 0, sizeof(fl2));
|
fl2.daddr = dst->in6;
|
if (!nf_ip6_route(net, (struct dst_entry **)&rt1,
|
flowi6_to_flowi(&fl1), false)) {
|
if (!nf_ip6_route(net, (struct dst_entry **)&rt2,
|
flowi6_to_flowi(&fl2), false)) {
|
if (ipv6_addr_equal(rt6_nexthop(rt1, &fl1.daddr),
|
rt6_nexthop(rt2, &fl2.daddr)) &&
|
rt1->dst.dev == rt2->dst.dev)
|
ret = 1;
|
dst_release(&rt2->dst);
|
}
|
dst_release(&rt1->dst);
|
}
|
break;
|
}
|
#endif
|
}
|
return ret;
|
|
}
|
|
static int expect_callforwarding(struct sk_buff *skb,
|
struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, int dataoff,
|
TransportAddress *taddr)
|
{
|
int dir = CTINFO2DIR(ctinfo);
|
int ret = 0;
|
__be16 port;
|
union nf_inet_addr addr;
|
struct nf_conntrack_expect *exp;
|
struct net *net = nf_ct_net(ct);
|
typeof(nat_callforwarding_hook) nat_callforwarding;
|
|
/* Read alternativeAddress */
|
if (!get_h225_addr(ct, *data, taddr, &addr, &port) || port == 0)
|
return 0;
|
|
/* If the calling party is on the same side of the forward-to party,
|
* we don't need to track the second call
|
*/
|
if (callforward_filter &&
|
callforward_do_filter(net, &addr, &ct->tuplehash[!dir].tuple.src.u3,
|
nf_ct_l3num(ct))) {
|
pr_debug("nf_ct_q931: Call Forwarding not tracked\n");
|
return 0;
|
}
|
|
/* Create expect for the second call leg */
|
if ((exp = nf_ct_expect_alloc(ct)) == NULL)
|
return -1;
|
nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
|
&ct->tuplehash[!dir].tuple.src.u3, &addr,
|
IPPROTO_TCP, NULL, &port);
|
exp->helper = nf_conntrack_helper_q931;
|
|
if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
|
&ct->tuplehash[!dir].tuple.dst.u3,
|
sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
|
(nat_callforwarding = rcu_dereference(nat_callforwarding_hook)) &&
|
nf_ct_l3num(ct) == NFPROTO_IPV4 &&
|
ct->status & IPS_NAT_MASK) {
|
/* Need NAT */
|
ret = nat_callforwarding(skb, ct, ctinfo,
|
protoff, data, dataoff,
|
taddr, port, exp);
|
} else { /* Conntrack only */
|
if (nf_ct_expect_related(exp, 0) == 0) {
|
pr_debug("nf_ct_q931: expect Call Forwarding ");
|
nf_ct_dump_tuple(&exp->tuple);
|
} else
|
ret = -1;
|
}
|
|
nf_ct_expect_put(exp);
|
|
return ret;
|
}
|
|
static int process_setup(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, int dataoff,
|
Setup_UUIE *setup)
|
{
|
int dir = CTINFO2DIR(ctinfo);
|
int ret;
|
int i;
|
__be16 port;
|
union nf_inet_addr addr;
|
typeof(set_h225_addr_hook) set_h225_addr;
|
|
pr_debug("nf_ct_q931: Setup\n");
|
|
if (setup->options & eSetup_UUIE_h245Address) {
|
ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
|
&setup->h245Address);
|
if (ret < 0)
|
return -1;
|
}
|
|
set_h225_addr = rcu_dereference(set_h225_addr_hook);
|
if ((setup->options & eSetup_UUIE_destCallSignalAddress) &&
|
(set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
|
ct->status & IPS_NAT_MASK &&
|
get_h225_addr(ct, *data, &setup->destCallSignalAddress,
|
&addr, &port) &&
|
memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
|
pr_debug("nf_ct_q931: set destCallSignalAddress %pI6:%hu->%pI6:%hu\n",
|
&addr, ntohs(port), &ct->tuplehash[!dir].tuple.src.u3,
|
ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
|
ret = set_h225_addr(skb, protoff, data, dataoff,
|
&setup->destCallSignalAddress,
|
&ct->tuplehash[!dir].tuple.src.u3,
|
ct->tuplehash[!dir].tuple.src.u.tcp.port);
|
if (ret < 0)
|
return -1;
|
}
|
|
if ((setup->options & eSetup_UUIE_sourceCallSignalAddress) &&
|
(set_h225_addr) && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
|
ct->status & IPS_NAT_MASK &&
|
get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
|
&addr, &port) &&
|
memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
|
pr_debug("nf_ct_q931: set sourceCallSignalAddress %pI6:%hu->%pI6:%hu\n",
|
&addr, ntohs(port), &ct->tuplehash[!dir].tuple.dst.u3,
|
ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
|
ret = set_h225_addr(skb, protoff, data, dataoff,
|
&setup->sourceCallSignalAddress,
|
&ct->tuplehash[!dir].tuple.dst.u3,
|
ct->tuplehash[!dir].tuple.dst.u.tcp.port);
|
if (ret < 0)
|
return -1;
|
}
|
|
if (setup->options & eSetup_UUIE_fastStart) {
|
for (i = 0; i < setup->fastStart.count; i++) {
|
ret = process_olc(skb, ct, ctinfo,
|
protoff, data, dataoff,
|
&setup->fastStart.item[i]);
|
if (ret < 0)
|
return -1;
|
}
|
}
|
|
return 0;
|
}
|
|
static int process_callproceeding(struct sk_buff *skb,
|
struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, int dataoff,
|
CallProceeding_UUIE *callproc)
|
{
|
int ret;
|
int i;
|
|
pr_debug("nf_ct_q931: CallProceeding\n");
|
|
if (callproc->options & eCallProceeding_UUIE_h245Address) {
|
ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
|
&callproc->h245Address);
|
if (ret < 0)
|
return -1;
|
}
|
|
if (callproc->options & eCallProceeding_UUIE_fastStart) {
|
for (i = 0; i < callproc->fastStart.count; i++) {
|
ret = process_olc(skb, ct, ctinfo,
|
protoff, data, dataoff,
|
&callproc->fastStart.item[i]);
|
if (ret < 0)
|
return -1;
|
}
|
}
|
|
return 0;
|
}
|
|
static int process_connect(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, int dataoff,
|
Connect_UUIE *connect)
|
{
|
int ret;
|
int i;
|
|
pr_debug("nf_ct_q931: Connect\n");
|
|
if (connect->options & eConnect_UUIE_h245Address) {
|
ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
|
&connect->h245Address);
|
if (ret < 0)
|
return -1;
|
}
|
|
if (connect->options & eConnect_UUIE_fastStart) {
|
for (i = 0; i < connect->fastStart.count; i++) {
|
ret = process_olc(skb, ct, ctinfo,
|
protoff, data, dataoff,
|
&connect->fastStart.item[i]);
|
if (ret < 0)
|
return -1;
|
}
|
}
|
|
return 0;
|
}
|
|
static int process_alerting(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, int dataoff,
|
Alerting_UUIE *alert)
|
{
|
int ret;
|
int i;
|
|
pr_debug("nf_ct_q931: Alerting\n");
|
|
if (alert->options & eAlerting_UUIE_h245Address) {
|
ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
|
&alert->h245Address);
|
if (ret < 0)
|
return -1;
|
}
|
|
if (alert->options & eAlerting_UUIE_fastStart) {
|
for (i = 0; i < alert->fastStart.count; i++) {
|
ret = process_olc(skb, ct, ctinfo,
|
protoff, data, dataoff,
|
&alert->fastStart.item[i]);
|
if (ret < 0)
|
return -1;
|
}
|
}
|
|
return 0;
|
}
|
|
static int process_facility(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, int dataoff,
|
Facility_UUIE *facility)
|
{
|
int ret;
|
int i;
|
|
pr_debug("nf_ct_q931: Facility\n");
|
|
if (facility->reason.choice == eFacilityReason_callForwarded) {
|
if (facility->options & eFacility_UUIE_alternativeAddress)
|
return expect_callforwarding(skb, ct, ctinfo,
|
protoff, data, dataoff,
|
&facility->
|
alternativeAddress);
|
return 0;
|
}
|
|
if (facility->options & eFacility_UUIE_h245Address) {
|
ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
|
&facility->h245Address);
|
if (ret < 0)
|
return -1;
|
}
|
|
if (facility->options & eFacility_UUIE_fastStart) {
|
for (i = 0; i < facility->fastStart.count; i++) {
|
ret = process_olc(skb, ct, ctinfo,
|
protoff, data, dataoff,
|
&facility->fastStart.item[i]);
|
if (ret < 0)
|
return -1;
|
}
|
}
|
|
return 0;
|
}
|
|
static int process_progress(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, int dataoff,
|
Progress_UUIE *progress)
|
{
|
int ret;
|
int i;
|
|
pr_debug("nf_ct_q931: Progress\n");
|
|
if (progress->options & eProgress_UUIE_h245Address) {
|
ret = expect_h245(skb, ct, ctinfo, protoff, data, dataoff,
|
&progress->h245Address);
|
if (ret < 0)
|
return -1;
|
}
|
|
if (progress->options & eProgress_UUIE_fastStart) {
|
for (i = 0; i < progress->fastStart.count; i++) {
|
ret = process_olc(skb, ct, ctinfo,
|
protoff, data, dataoff,
|
&progress->fastStart.item[i]);
|
if (ret < 0)
|
return -1;
|
}
|
}
|
|
return 0;
|
}
|
|
static int process_q931(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff, unsigned char **data, int dataoff,
|
Q931 *q931)
|
{
|
H323_UU_PDU *pdu = &q931->UUIE.h323_uu_pdu;
|
int i;
|
int ret = 0;
|
|
switch (pdu->h323_message_body.choice) {
|
case eH323_UU_PDU_h323_message_body_setup:
|
ret = process_setup(skb, ct, ctinfo, protoff, data, dataoff,
|
&pdu->h323_message_body.setup);
|
break;
|
case eH323_UU_PDU_h323_message_body_callProceeding:
|
ret = process_callproceeding(skb, ct, ctinfo,
|
protoff, data, dataoff,
|
&pdu->h323_message_body.
|
callProceeding);
|
break;
|
case eH323_UU_PDU_h323_message_body_connect:
|
ret = process_connect(skb, ct, ctinfo, protoff, data, dataoff,
|
&pdu->h323_message_body.connect);
|
break;
|
case eH323_UU_PDU_h323_message_body_alerting:
|
ret = process_alerting(skb, ct, ctinfo, protoff, data, dataoff,
|
&pdu->h323_message_body.alerting);
|
break;
|
case eH323_UU_PDU_h323_message_body_facility:
|
ret = process_facility(skb, ct, ctinfo, protoff, data, dataoff,
|
&pdu->h323_message_body.facility);
|
break;
|
case eH323_UU_PDU_h323_message_body_progress:
|
ret = process_progress(skb, ct, ctinfo, protoff, data, dataoff,
|
&pdu->h323_message_body.progress);
|
break;
|
default:
|
pr_debug("nf_ct_q931: Q.931 signal %d\n",
|
pdu->h323_message_body.choice);
|
break;
|
}
|
|
if (ret < 0)
|
return -1;
|
|
if (pdu->options & eH323_UU_PDU_h245Control) {
|
for (i = 0; i < pdu->h245Control.count; i++) {
|
ret = process_h245(skb, ct, ctinfo,
|
protoff, data, dataoff,
|
&pdu->h245Control.item[i]);
|
if (ret < 0)
|
return -1;
|
}
|
}
|
|
return 0;
|
}
|
|
static int q931_help(struct sk_buff *skb, unsigned int protoff,
|
struct nf_conn *ct, enum ip_conntrack_info ctinfo)
|
{
|
static Q931 q931;
|
unsigned char *data = NULL;
|
int datalen;
|
int dataoff;
|
int ret;
|
|
/* Until there's been traffic both ways, don't look in packets. */
|
if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
|
return NF_ACCEPT;
|
|
pr_debug("nf_ct_q931: skblen = %u\n", skb->len);
|
|
spin_lock_bh(&nf_h323_lock);
|
|
/* Process each TPKT */
|
while (get_tpkt_data(skb, protoff, ct, ctinfo,
|
&data, &datalen, &dataoff)) {
|
pr_debug("nf_ct_q931: TPKT len=%d ", datalen);
|
nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
|
|
/* Decode Q.931 signal */
|
ret = DecodeQ931(data, datalen, &q931);
|
if (ret < 0) {
|
pr_debug("nf_ct_q931: decoding error: %s\n",
|
ret == H323_ERROR_BOUND ?
|
"out of bound" : "out of range");
|
/* We don't drop when decoding error */
|
break;
|
}
|
|
/* Process Q.931 signal */
|
if (process_q931(skb, ct, ctinfo, protoff,
|
&data, dataoff, &q931) < 0)
|
goto drop;
|
}
|
|
spin_unlock_bh(&nf_h323_lock);
|
return NF_ACCEPT;
|
|
drop:
|
spin_unlock_bh(&nf_h323_lock);
|
nf_ct_helper_log(skb, ct, "cannot process Q.931 message");
|
return NF_DROP;
|
}
|
|
static const struct nf_conntrack_expect_policy q931_exp_policy = {
|
/* T.120 and H.245 */
|
.max_expected = H323_RTP_CHANNEL_MAX * 4 + 4,
|
.timeout = 240,
|
};
|
|
static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
|
{
|
.name = "Q.931",
|
.me = THIS_MODULE,
|
.tuple.src.l3num = AF_INET,
|
.tuple.src.u.tcp.port = cpu_to_be16(Q931_PORT),
|
.tuple.dst.protonum = IPPROTO_TCP,
|
.help = q931_help,
|
.expect_policy = &q931_exp_policy,
|
},
|
{
|
.name = "Q.931",
|
.me = THIS_MODULE,
|
.tuple.src.l3num = AF_INET6,
|
.tuple.src.u.tcp.port = cpu_to_be16(Q931_PORT),
|
.tuple.dst.protonum = IPPROTO_TCP,
|
.help = q931_help,
|
.expect_policy = &q931_exp_policy,
|
},
|
};
|
|
static unsigned char *get_udp_data(struct sk_buff *skb, unsigned int protoff,
|
int *datalen)
|
{
|
const struct udphdr *uh;
|
struct udphdr _uh;
|
int dataoff;
|
|
uh = skb_header_pointer(skb, protoff, sizeof(_uh), &_uh);
|
if (uh == NULL)
|
return NULL;
|
dataoff = protoff + sizeof(_uh);
|
if (dataoff >= skb->len)
|
return NULL;
|
*datalen = skb->len - dataoff;
|
return skb_header_pointer(skb, dataoff, *datalen, h323_buffer);
|
}
|
|
static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
|
union nf_inet_addr *addr,
|
__be16 port)
|
{
|
struct net *net = nf_ct_net(ct);
|
struct nf_conntrack_expect *exp;
|
struct nf_conntrack_tuple tuple;
|
|
memset(&tuple.src.u3, 0, sizeof(tuple.src.u3));
|
tuple.src.u.tcp.port = 0;
|
memcpy(&tuple.dst.u3, addr, sizeof(tuple.dst.u3));
|
tuple.dst.u.tcp.port = port;
|
tuple.dst.protonum = IPPROTO_TCP;
|
|
exp = __nf_ct_expect_find(net, nf_ct_zone(ct), &tuple);
|
if (exp && exp->master == ct)
|
return exp;
|
return NULL;
|
}
|
|
static int expect_q931(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff, unsigned char **data,
|
TransportAddress *taddr, int count)
|
{
|
struct nf_ct_h323_master *info = nfct_help_data(ct);
|
int dir = CTINFO2DIR(ctinfo);
|
int ret = 0;
|
int i;
|
__be16 port;
|
union nf_inet_addr addr;
|
struct nf_conntrack_expect *exp;
|
typeof(nat_q931_hook) nat_q931;
|
|
/* Look for the first related address */
|
for (i = 0; i < count; i++) {
|
if (get_h225_addr(ct, *data, &taddr[i], &addr, &port) &&
|
memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3,
|
sizeof(addr)) == 0 && port != 0)
|
break;
|
}
|
|
if (i >= count) /* Not found */
|
return 0;
|
|
/* Create expect for Q.931 */
|
if ((exp = nf_ct_expect_alloc(ct)) == NULL)
|
return -1;
|
nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
|
gkrouted_only ? /* only accept calls from GK? */
|
&ct->tuplehash[!dir].tuple.src.u3 : NULL,
|
&ct->tuplehash[!dir].tuple.dst.u3,
|
IPPROTO_TCP, NULL, &port);
|
exp->helper = nf_conntrack_helper_q931;
|
exp->flags = NF_CT_EXPECT_PERMANENT; /* Accept multiple calls */
|
|
nat_q931 = rcu_dereference(nat_q931_hook);
|
if (nat_q931 && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
|
ct->status & IPS_NAT_MASK) { /* Need NAT */
|
ret = nat_q931(skb, ct, ctinfo, protoff, data,
|
taddr, i, port, exp);
|
} else { /* Conntrack only */
|
if (nf_ct_expect_related(exp, 0) == 0) {
|
pr_debug("nf_ct_ras: expect Q.931 ");
|
nf_ct_dump_tuple(&exp->tuple);
|
|
/* Save port for looking up expect in processing RCF */
|
info->sig_port[dir] = port;
|
} else
|
ret = -1;
|
}
|
|
nf_ct_expect_put(exp);
|
|
return ret;
|
}
|
|
static int process_grq(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, GatekeeperRequest *grq)
|
{
|
typeof(set_ras_addr_hook) set_ras_addr;
|
|
pr_debug("nf_ct_ras: GRQ\n");
|
|
set_ras_addr = rcu_dereference(set_ras_addr_hook);
|
if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
|
ct->status & IPS_NAT_MASK) /* NATed */
|
return set_ras_addr(skb, ct, ctinfo, protoff, data,
|
&grq->rasAddress, 1);
|
return 0;
|
}
|
|
static int process_gcf(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, GatekeeperConfirm *gcf)
|
{
|
int dir = CTINFO2DIR(ctinfo);
|
int ret = 0;
|
__be16 port;
|
union nf_inet_addr addr;
|
struct nf_conntrack_expect *exp;
|
|
pr_debug("nf_ct_ras: GCF\n");
|
|
if (!get_h225_addr(ct, *data, &gcf->rasAddress, &addr, &port))
|
return 0;
|
|
/* Registration port is the same as discovery port */
|
if (!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
|
port == ct->tuplehash[dir].tuple.src.u.udp.port)
|
return 0;
|
|
/* Avoid RAS expectation loops. A GCF is never expected. */
|
if (test_bit(IPS_EXPECTED_BIT, &ct->status))
|
return 0;
|
|
/* Need new expect */
|
if ((exp = nf_ct_expect_alloc(ct)) == NULL)
|
return -1;
|
nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
|
&ct->tuplehash[!dir].tuple.src.u3, &addr,
|
IPPROTO_UDP, NULL, &port);
|
exp->helper = nf_conntrack_helper_ras;
|
|
if (nf_ct_expect_related(exp, 0) == 0) {
|
pr_debug("nf_ct_ras: expect RAS ");
|
nf_ct_dump_tuple(&exp->tuple);
|
} else
|
ret = -1;
|
|
nf_ct_expect_put(exp);
|
|
return ret;
|
}
|
|
static int process_rrq(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, RegistrationRequest *rrq)
|
{
|
struct nf_ct_h323_master *info = nfct_help_data(ct);
|
int ret;
|
typeof(set_ras_addr_hook) set_ras_addr;
|
|
pr_debug("nf_ct_ras: RRQ\n");
|
|
ret = expect_q931(skb, ct, ctinfo, protoff, data,
|
rrq->callSignalAddress.item,
|
rrq->callSignalAddress.count);
|
if (ret < 0)
|
return -1;
|
|
set_ras_addr = rcu_dereference(set_ras_addr_hook);
|
if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
|
ct->status & IPS_NAT_MASK) {
|
ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
|
rrq->rasAddress.item,
|
rrq->rasAddress.count);
|
if (ret < 0)
|
return -1;
|
}
|
|
if (rrq->options & eRegistrationRequest_timeToLive) {
|
pr_debug("nf_ct_ras: RRQ TTL = %u seconds\n", rrq->timeToLive);
|
info->timeout = rrq->timeToLive;
|
} else
|
info->timeout = default_rrq_ttl;
|
|
return 0;
|
}
|
|
static int process_rcf(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, RegistrationConfirm *rcf)
|
{
|
struct nf_ct_h323_master *info = nfct_help_data(ct);
|
int dir = CTINFO2DIR(ctinfo);
|
int ret;
|
struct nf_conntrack_expect *exp;
|
typeof(set_sig_addr_hook) set_sig_addr;
|
|
pr_debug("nf_ct_ras: RCF\n");
|
|
set_sig_addr = rcu_dereference(set_sig_addr_hook);
|
if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
|
ct->status & IPS_NAT_MASK) {
|
ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
|
rcf->callSignalAddress.item,
|
rcf->callSignalAddress.count);
|
if (ret < 0)
|
return -1;
|
}
|
|
if (rcf->options & eRegistrationConfirm_timeToLive) {
|
pr_debug("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
|
info->timeout = rcf->timeToLive;
|
}
|
|
if (info->timeout > 0) {
|
pr_debug("nf_ct_ras: set RAS connection timeout to "
|
"%u seconds\n", info->timeout);
|
nf_ct_refresh(ct, skb, info->timeout * HZ);
|
|
/* Set expect timeout */
|
spin_lock_bh(&nf_conntrack_expect_lock);
|
exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
|
info->sig_port[!dir]);
|
if (exp) {
|
pr_debug("nf_ct_ras: set Q.931 expect "
|
"timeout to %u seconds for",
|
info->timeout);
|
nf_ct_dump_tuple(&exp->tuple);
|
mod_timer_pending(&exp->timeout,
|
jiffies + info->timeout * HZ);
|
}
|
spin_unlock_bh(&nf_conntrack_expect_lock);
|
}
|
|
return 0;
|
}
|
|
static int process_urq(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, UnregistrationRequest *urq)
|
{
|
struct nf_ct_h323_master *info = nfct_help_data(ct);
|
int dir = CTINFO2DIR(ctinfo);
|
int ret;
|
typeof(set_sig_addr_hook) set_sig_addr;
|
|
pr_debug("nf_ct_ras: URQ\n");
|
|
set_sig_addr = rcu_dereference(set_sig_addr_hook);
|
if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
|
ct->status & IPS_NAT_MASK) {
|
ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
|
urq->callSignalAddress.item,
|
urq->callSignalAddress.count);
|
if (ret < 0)
|
return -1;
|
}
|
|
/* Clear old expect */
|
nf_ct_remove_expectations(ct);
|
info->sig_port[dir] = 0;
|
info->sig_port[!dir] = 0;
|
|
/* Give it 30 seconds for UCF or URJ */
|
nf_ct_refresh(ct, skb, 30 * HZ);
|
|
return 0;
|
}
|
|
static int process_arq(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, AdmissionRequest *arq)
|
{
|
const struct nf_ct_h323_master *info = nfct_help_data(ct);
|
int dir = CTINFO2DIR(ctinfo);
|
__be16 port;
|
union nf_inet_addr addr;
|
typeof(set_h225_addr_hook) set_h225_addr;
|
|
pr_debug("nf_ct_ras: ARQ\n");
|
|
set_h225_addr = rcu_dereference(set_h225_addr_hook);
|
if ((arq->options & eAdmissionRequest_destCallSignalAddress) &&
|
get_h225_addr(ct, *data, &arq->destCallSignalAddress,
|
&addr, &port) &&
|
!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
|
port == info->sig_port[dir] &&
|
nf_ct_l3num(ct) == NFPROTO_IPV4 &&
|
set_h225_addr && ct->status & IPS_NAT_MASK) {
|
/* Answering ARQ */
|
return set_h225_addr(skb, protoff, data, 0,
|
&arq->destCallSignalAddress,
|
&ct->tuplehash[!dir].tuple.dst.u3,
|
info->sig_port[!dir]);
|
}
|
|
if ((arq->options & eAdmissionRequest_srcCallSignalAddress) &&
|
get_h225_addr(ct, *data, &arq->srcCallSignalAddress,
|
&addr, &port) &&
|
!memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) &&
|
set_h225_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
|
ct->status & IPS_NAT_MASK) {
|
/* Calling ARQ */
|
return set_h225_addr(skb, protoff, data, 0,
|
&arq->srcCallSignalAddress,
|
&ct->tuplehash[!dir].tuple.dst.u3,
|
port);
|
}
|
|
return 0;
|
}
|
|
static int process_acf(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, AdmissionConfirm *acf)
|
{
|
int dir = CTINFO2DIR(ctinfo);
|
int ret = 0;
|
__be16 port;
|
union nf_inet_addr addr;
|
struct nf_conntrack_expect *exp;
|
typeof(set_sig_addr_hook) set_sig_addr;
|
|
pr_debug("nf_ct_ras: ACF\n");
|
|
if (!get_h225_addr(ct, *data, &acf->destCallSignalAddress,
|
&addr, &port))
|
return 0;
|
|
if (!memcmp(&addr, &ct->tuplehash[dir].tuple.dst.u3, sizeof(addr))) {
|
/* Answering ACF */
|
set_sig_addr = rcu_dereference(set_sig_addr_hook);
|
if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
|
ct->status & IPS_NAT_MASK)
|
return set_sig_addr(skb, ct, ctinfo, protoff, data,
|
&acf->destCallSignalAddress, 1);
|
return 0;
|
}
|
|
/* Need new expect */
|
if ((exp = nf_ct_expect_alloc(ct)) == NULL)
|
return -1;
|
nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
|
&ct->tuplehash[!dir].tuple.src.u3, &addr,
|
IPPROTO_TCP, NULL, &port);
|
exp->flags = NF_CT_EXPECT_PERMANENT;
|
exp->helper = nf_conntrack_helper_q931;
|
|
if (nf_ct_expect_related(exp, 0) == 0) {
|
pr_debug("nf_ct_ras: expect Q.931 ");
|
nf_ct_dump_tuple(&exp->tuple);
|
} else
|
ret = -1;
|
|
nf_ct_expect_put(exp);
|
|
return ret;
|
}
|
|
static int process_lrq(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, LocationRequest *lrq)
|
{
|
typeof(set_ras_addr_hook) set_ras_addr;
|
|
pr_debug("nf_ct_ras: LRQ\n");
|
|
set_ras_addr = rcu_dereference(set_ras_addr_hook);
|
if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
|
ct->status & IPS_NAT_MASK)
|
return set_ras_addr(skb, ct, ctinfo, protoff, data,
|
&lrq->replyAddress, 1);
|
return 0;
|
}
|
|
static int process_lcf(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, LocationConfirm *lcf)
|
{
|
int dir = CTINFO2DIR(ctinfo);
|
int ret = 0;
|
__be16 port;
|
union nf_inet_addr addr;
|
struct nf_conntrack_expect *exp;
|
|
pr_debug("nf_ct_ras: LCF\n");
|
|
if (!get_h225_addr(ct, *data, &lcf->callSignalAddress,
|
&addr, &port))
|
return 0;
|
|
/* Need new expect for call signal */
|
if ((exp = nf_ct_expect_alloc(ct)) == NULL)
|
return -1;
|
nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, nf_ct_l3num(ct),
|
&ct->tuplehash[!dir].tuple.src.u3, &addr,
|
IPPROTO_TCP, NULL, &port);
|
exp->flags = NF_CT_EXPECT_PERMANENT;
|
exp->helper = nf_conntrack_helper_q931;
|
|
if (nf_ct_expect_related(exp, 0) == 0) {
|
pr_debug("nf_ct_ras: expect Q.931 ");
|
nf_ct_dump_tuple(&exp->tuple);
|
} else
|
ret = -1;
|
|
nf_ct_expect_put(exp);
|
|
/* Ignore rasAddress */
|
|
return ret;
|
}
|
|
static int process_irr(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, InfoRequestResponse *irr)
|
{
|
int ret;
|
typeof(set_ras_addr_hook) set_ras_addr;
|
typeof(set_sig_addr_hook) set_sig_addr;
|
|
pr_debug("nf_ct_ras: IRR\n");
|
|
set_ras_addr = rcu_dereference(set_ras_addr_hook);
|
if (set_ras_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
|
ct->status & IPS_NAT_MASK) {
|
ret = set_ras_addr(skb, ct, ctinfo, protoff, data,
|
&irr->rasAddress, 1);
|
if (ret < 0)
|
return -1;
|
}
|
|
set_sig_addr = rcu_dereference(set_sig_addr_hook);
|
if (set_sig_addr && nf_ct_l3num(ct) == NFPROTO_IPV4 &&
|
ct->status & IPS_NAT_MASK) {
|
ret = set_sig_addr(skb, ct, ctinfo, protoff, data,
|
irr->callSignalAddress.item,
|
irr->callSignalAddress.count);
|
if (ret < 0)
|
return -1;
|
}
|
|
return 0;
|
}
|
|
static int process_ras(struct sk_buff *skb, struct nf_conn *ct,
|
enum ip_conntrack_info ctinfo,
|
unsigned int protoff,
|
unsigned char **data, RasMessage *ras)
|
{
|
switch (ras->choice) {
|
case eRasMessage_gatekeeperRequest:
|
return process_grq(skb, ct, ctinfo, protoff, data,
|
&ras->gatekeeperRequest);
|
case eRasMessage_gatekeeperConfirm:
|
return process_gcf(skb, ct, ctinfo, protoff, data,
|
&ras->gatekeeperConfirm);
|
case eRasMessage_registrationRequest:
|
return process_rrq(skb, ct, ctinfo, protoff, data,
|
&ras->registrationRequest);
|
case eRasMessage_registrationConfirm:
|
return process_rcf(skb, ct, ctinfo, protoff, data,
|
&ras->registrationConfirm);
|
case eRasMessage_unregistrationRequest:
|
return process_urq(skb, ct, ctinfo, protoff, data,
|
&ras->unregistrationRequest);
|
case eRasMessage_admissionRequest:
|
return process_arq(skb, ct, ctinfo, protoff, data,
|
&ras->admissionRequest);
|
case eRasMessage_admissionConfirm:
|
return process_acf(skb, ct, ctinfo, protoff, data,
|
&ras->admissionConfirm);
|
case eRasMessage_locationRequest:
|
return process_lrq(skb, ct, ctinfo, protoff, data,
|
&ras->locationRequest);
|
case eRasMessage_locationConfirm:
|
return process_lcf(skb, ct, ctinfo, protoff, data,
|
&ras->locationConfirm);
|
case eRasMessage_infoRequestResponse:
|
return process_irr(skb, ct, ctinfo, protoff, data,
|
&ras->infoRequestResponse);
|
default:
|
pr_debug("nf_ct_ras: RAS message %d\n", ras->choice);
|
break;
|
}
|
|
return 0;
|
}
|
|
static int ras_help(struct sk_buff *skb, unsigned int protoff,
|
struct nf_conn *ct, enum ip_conntrack_info ctinfo)
|
{
|
static RasMessage ras;
|
unsigned char *data;
|
int datalen = 0;
|
int ret;
|
|
pr_debug("nf_ct_ras: skblen = %u\n", skb->len);
|
|
spin_lock_bh(&nf_h323_lock);
|
|
/* Get UDP data */
|
data = get_udp_data(skb, protoff, &datalen);
|
if (data == NULL)
|
goto accept;
|
pr_debug("nf_ct_ras: RAS message len=%d ", datalen);
|
nf_ct_dump_tuple(&ct->tuplehash[CTINFO2DIR(ctinfo)].tuple);
|
|
/* Decode RAS message */
|
ret = DecodeRasMessage(data, datalen, &ras);
|
if (ret < 0) {
|
pr_debug("nf_ct_ras: decoding error: %s\n",
|
ret == H323_ERROR_BOUND ?
|
"out of bound" : "out of range");
|
goto accept;
|
}
|
|
/* Process RAS message */
|
if (process_ras(skb, ct, ctinfo, protoff, &data, &ras) < 0)
|
goto drop;
|
|
accept:
|
spin_unlock_bh(&nf_h323_lock);
|
return NF_ACCEPT;
|
|
drop:
|
spin_unlock_bh(&nf_h323_lock);
|
nf_ct_helper_log(skb, ct, "cannot process RAS message");
|
return NF_DROP;
|
}
|
|
static const struct nf_conntrack_expect_policy ras_exp_policy = {
|
.max_expected = 32,
|
.timeout = 240,
|
};
|
|
static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
|
{
|
.name = "RAS",
|
.me = THIS_MODULE,
|
.tuple.src.l3num = AF_INET,
|
.tuple.src.u.udp.port = cpu_to_be16(RAS_PORT),
|
.tuple.dst.protonum = IPPROTO_UDP,
|
.help = ras_help,
|
.expect_policy = &ras_exp_policy,
|
},
|
{
|
.name = "RAS",
|
.me = THIS_MODULE,
|
.tuple.src.l3num = AF_INET6,
|
.tuple.src.u.udp.port = cpu_to_be16(RAS_PORT),
|
.tuple.dst.protonum = IPPROTO_UDP,
|
.help = ras_help,
|
.expect_policy = &ras_exp_policy,
|
},
|
};
|
|
static int __init h323_helper_init(void)
|
{
|
int ret;
|
|
ret = nf_conntrack_helper_register(&nf_conntrack_helper_h245);
|
if (ret < 0)
|
return ret;
|
ret = nf_conntrack_helpers_register(nf_conntrack_helper_q931,
|
ARRAY_SIZE(nf_conntrack_helper_q931));
|
if (ret < 0)
|
goto err1;
|
ret = nf_conntrack_helpers_register(nf_conntrack_helper_ras,
|
ARRAY_SIZE(nf_conntrack_helper_ras));
|
if (ret < 0)
|
goto err2;
|
|
return 0;
|
err2:
|
nf_conntrack_helpers_unregister(nf_conntrack_helper_q931,
|
ARRAY_SIZE(nf_conntrack_helper_q931));
|
err1:
|
nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
|
return ret;
|
}
|
|
static void __exit h323_helper_exit(void)
|
{
|
nf_conntrack_helpers_unregister(nf_conntrack_helper_ras,
|
ARRAY_SIZE(nf_conntrack_helper_ras));
|
nf_conntrack_helpers_unregister(nf_conntrack_helper_q931,
|
ARRAY_SIZE(nf_conntrack_helper_q931));
|
nf_conntrack_helper_unregister(&nf_conntrack_helper_h245);
|
}
|
|
static void __exit nf_conntrack_h323_fini(void)
|
{
|
h323_helper_exit();
|
kfree(h323_buffer);
|
pr_debug("nf_ct_h323: fini\n");
|
}
|
|
static int __init nf_conntrack_h323_init(void)
|
{
|
int ret;
|
|
NF_CT_HELPER_BUILD_BUG_ON(sizeof(struct nf_ct_h323_master));
|
|
h323_buffer = kmalloc(65536, GFP_KERNEL);
|
if (!h323_buffer)
|
return -ENOMEM;
|
ret = h323_helper_init();
|
if (ret < 0)
|
goto err1;
|
pr_debug("nf_ct_h323: init success\n");
|
return 0;
|
err1:
|
kfree(h323_buffer);
|
return ret;
|
}
|
|
module_init(nf_conntrack_h323_init);
|
module_exit(nf_conntrack_h323_fini);
|
|
EXPORT_SYMBOL_GPL(get_h225_addr);
|
EXPORT_SYMBOL_GPL(set_h245_addr_hook);
|
EXPORT_SYMBOL_GPL(set_h225_addr_hook);
|
EXPORT_SYMBOL_GPL(set_sig_addr_hook);
|
EXPORT_SYMBOL_GPL(set_ras_addr_hook);
|
EXPORT_SYMBOL_GPL(nat_rtp_rtcp_hook);
|
EXPORT_SYMBOL_GPL(nat_t120_hook);
|
EXPORT_SYMBOL_GPL(nat_h245_hook);
|
EXPORT_SYMBOL_GPL(nat_callforwarding_hook);
|
EXPORT_SYMBOL_GPL(nat_q931_hook);
|
|
MODULE_AUTHOR("Jing Min Zhao <zhaojingmin@users.sourceforge.net>");
|
MODULE_DESCRIPTION("H.323 connection tracking helper");
|
MODULE_LICENSE("GPL");
|
MODULE_ALIAS("ip_conntrack_h323");
|
MODULE_ALIAS_NFCT_HELPER("RAS");
|
MODULE_ALIAS_NFCT_HELPER("Q.931");
|
MODULE_ALIAS_NFCT_HELPER("H.245");
|
