This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / net / netfilter / nf_conntrack_h323_main.c
diff --git a/net/netfilter/nf_conntrack_h323_main.c b/net/netfilter/nf_conntrack_h323_main.c
new file mode 100644 (file)
index 0000000..6d85689
--- /dev/null
@@ -0,0 +1,1856 @@
+/*
+ * H.323 connection tracking helper
+ *
+ * Copyright (c) 2006 Jing Min Zhao <zhaojingmin@users.sourceforge.net>
+ *
+ * This source code is licensed under General Public License version 2.
+ *
+ * Based on the 'brute force' H.323 connection tracking module by
+ * Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
+ *
+ * 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/udp.h>
+#include <linux/tcp.h>
+#include <linux/skbuff.h>
+#include <net/route.h>
+#include <net/ip6_route.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 <linux/netfilter/nf_conntrack_h323.h>
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+/* 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 int callforward_filter __read_mostly = 1;
+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 **pskb,
+                          unsigned char **data, int dataoff,
+                          H245_TransportAddress *taddr,
+                          union nf_conntrack_address *addr, __be16 port)
+                          __read_mostly;
+int (*set_h225_addr_hook) (struct sk_buff **pskb,
+                          unsigned char **data, int dataoff,
+                          TransportAddress *taddr,
+                          union nf_conntrack_address *addr, __be16 port)
+                          __read_mostly;
+int (*set_sig_addr_hook) (struct sk_buff **pskb,
+                         struct nf_conn *ct,
+                         enum ip_conntrack_info ctinfo,
+                         unsigned char **data,
+                         TransportAddress *taddr, int count) __read_mostly;
+int (*set_ras_addr_hook) (struct sk_buff **pskb,
+                         struct nf_conn *ct,
+                         enum ip_conntrack_info ctinfo,
+                         unsigned char **data,
+                         TransportAddress *taddr, int count) __read_mostly;
+int (*nat_rtp_rtcp_hook) (struct sk_buff **pskb,
+                         struct nf_conn *ct,
+                         enum ip_conntrack_info ctinfo,
+                         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 **pskb,
+                     struct nf_conn *ct,
+                     enum ip_conntrack_info ctinfo,
+                     unsigned char **data, int dataoff,
+                     H245_TransportAddress *taddr, __be16 port,
+                     struct nf_conntrack_expect *exp) __read_mostly;
+int (*nat_h245_hook) (struct sk_buff **pskb,
+                     struct nf_conn *ct,
+                     enum ip_conntrack_info ctinfo,
+                     unsigned char **data, int dataoff,
+                     TransportAddress *taddr, __be16 port,
+                     struct nf_conntrack_expect *exp) __read_mostly;
+int (*nat_callforwarding_hook) (struct sk_buff **pskb,
+                               struct nf_conn *ct,
+                               enum ip_conntrack_info ctinfo,
+                               unsigned char **data, int dataoff,
+                               TransportAddress *taddr, __be16 port,
+                               struct nf_conntrack_expect *exp) __read_mostly;
+int (*nat_q931_hook) (struct sk_buff **pskb,
+                     struct nf_conn *ct,
+                     enum ip_conntrack_info ctinfo,
+                     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 **pskb, 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(ct)->help.ct_h323_info;
+       int dir = CTINFO2DIR(ctinfo);
+       struct tcphdr _tcph, *th;
+       int tcpdatalen;
+       int tcpdataoff;
+       unsigned char *tpkt;
+       int tpktlen;
+       int tpktoff;
+
+       /* Get TCP header */
+       th = skb_header_pointer(*pskb, protoff, sizeof(_tcph), &_tcph);
+       if (th == NULL)
+               return 0;
+
+       /* Get TCP data offset */
+       tcpdataoff = protoff + th->doff * 4;
+
+       /* Get TCP data length */
+       tcpdatalen = (*pskb)->len - tcpdataoff;
+       if (tcpdatalen <= 0)    /* No TCP data */
+               goto clear_out;
+
+       if (*data == NULL) {    /* first TPKT */
+               /* Get first TPKT pointer */
+               tpkt = skb_header_pointer(*pskb, 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) {
+                               DEBUGP("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 */
+                               if (net_ratelimit())
+                                       printk("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 */
+                       DEBUGP("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;
+               }
+
+               if (net_ratelimit())
+                       printk("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:
+       /* 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, unsigned char *data,
+                        H245_TransportAddress *taddr,
+                        union nf_conntrack_address *addr, __be16 *port)
+{
+       unsigned char *p;
+       int family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
+       int len;
+
+       if (taddr->choice != eH245_TransportAddress_unicastAddress)
+               return 0;
+
+       switch (taddr->unicastAddress.choice) {
+       case eUnicastAddress_iPAddress:
+               if (family != AF_INET)
+                       return 0;
+               p = data + taddr->unicastAddress.iPAddress.network;
+               len = 4;
+               break;
+       case eUnicastAddress_iP6Address:
+               if (family != AF_INET6)
+                       return 0;
+               p = data + taddr->unicastAddress.iP6Address.network;
+               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_rtp_rtcp(struct sk_buff **pskb, struct nf_conn *ct,
+                          enum ip_conntrack_info ctinfo,
+                          unsigned char **data, int dataoff,
+                          H245_TransportAddress *taddr)
+{
+       int dir = CTINFO2DIR(ctinfo);
+       int ret = 0;
+       __be16 port;
+       __be16 rtp_port, rtcp_port;
+       union nf_conntrack_address addr;
+       struct nf_conntrack_expect *rtp_exp;
+       struct nf_conntrack_expect *rtcp_exp;
+       typeof(nat_rtp_rtcp_hook) nat_rtp_rtcp;
+
+       /* Read RTP or RTCP address */
+       if (!get_h245_addr(ct, *data, taddr, &addr, &port) ||
+           memcmp(&addr, &ct->tuplehash[dir].tuple.src.u3, sizeof(addr)) ||
+           port == 0)
+               return 0;
+
+       /* RTP port is even */
+       port &= htons(~1);
+       rtp_port = port;
+       rtcp_port = htons(ntohs(port) + 1);
+
+       /* Create expect for RTP */
+       if ((rtp_exp = nf_conntrack_expect_alloc(ct)) == NULL)
+               return -1;
+       nf_conntrack_expect_init(rtp_exp, ct->tuplehash[!dir].tuple.src.l3num,
+                                &ct->tuplehash[!dir].tuple.src.u3,
+                                &ct->tuplehash[!dir].tuple.dst.u3,
+                                IPPROTO_UDP, NULL, &rtp_port);
+
+       /* Create expect for RTCP */
+       if ((rtcp_exp = nf_conntrack_expect_alloc(ct)) == NULL) {
+               nf_conntrack_expect_put(rtp_exp);
+               return -1;
+       }
+       nf_conntrack_expect_init(rtcp_exp, ct->tuplehash[!dir].tuple.src.l3num,
+                                &ct->tuplehash[!dir].tuple.src.u3,
+                                &ct->tuplehash[!dir].tuple.dst.u3,
+                                IPPROTO_UDP, NULL, &rtcp_port);
+
+       if (memcmp(&ct->tuplehash[dir].tuple.src.u3,
+                  &ct->tuplehash[!dir].tuple.dst.u3,
+                  sizeof(ct->tuplehash[dir].tuple.src.u3)) &&
+                  (nat_rtp_rtcp = rcu_dereference(nat_rtp_rtcp_hook)) &&
+                  ct->status & IPS_NAT_MASK) {
+               /* NAT needed */
+               ret = nat_rtp_rtcp(pskb, ct, ctinfo, data, dataoff,
+                                  taddr, port, rtp_port, rtp_exp, rtcp_exp);
+       } else {                /* Conntrack only */
+               if (nf_conntrack_expect_related(rtp_exp) == 0) {
+                       if (nf_conntrack_expect_related(rtcp_exp) == 0) {
+                               DEBUGP("nf_ct_h323: expect RTP ");
+                               NF_CT_DUMP_TUPLE(&rtp_exp->tuple);
+                               DEBUGP("nf_ct_h323: expect RTCP ");
+                               NF_CT_DUMP_TUPLE(&rtcp_exp->tuple);
+                       } else {
+                               nf_conntrack_unexpect_related(rtp_exp);
+                               ret = -1;
+                       }
+               } else
+                       ret = -1;
+       }
+
+       nf_conntrack_expect_put(rtp_exp);
+       nf_conntrack_expect_put(rtcp_exp);
+
+       return ret;
+}
+
+/****************************************************************************/
+static int expect_t120(struct sk_buff **pskb,
+                      struct nf_conn *ct,
+                      enum ip_conntrack_info ctinfo,
+                      unsigned char **data, int dataoff,
+                      H245_TransportAddress *taddr)
+{
+       int dir = CTINFO2DIR(ctinfo);
+       int ret = 0;
+       __be16 port;
+       union nf_conntrack_address 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_conntrack_expect_alloc(ct)) == NULL)
+               return -1;
+       nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+                                &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)) &&
+           ct->status & IPS_NAT_MASK) {
+               /* NAT needed */
+               ret = nat_t120(pskb, ct, ctinfo, data, dataoff, taddr,
+                              port, exp);
+       } else {                /* Conntrack only */
+               if (nf_conntrack_expect_related(exp) == 0) {
+                       DEBUGP("nf_ct_h323: expect T.120 ");
+                       NF_CT_DUMP_TUPLE(&exp->tuple);
+               } else
+                       ret = -1;
+       }
+
+       nf_conntrack_expect_put(exp);
+
+       return ret;
+}
+
+/****************************************************************************/
+static int process_h245_channel(struct sk_buff **pskb,
+                               struct nf_conn *ct,
+                               enum ip_conntrack_info ctinfo,
+                               unsigned char **data, int dataoff,
+                               H2250LogicalChannelParameters *channel)
+{
+       int ret;
+
+       if (channel->options & eH2250LogicalChannelParameters_mediaChannel) {
+               /* RTP */
+               ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff,
+                                     &channel->mediaChannel);
+               if (ret < 0)
+                       return -1;
+       }
+
+       if (channel->
+           options & eH2250LogicalChannelParameters_mediaControlChannel) {
+               /* RTCP */
+               ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff,
+                                     &channel->mediaControlChannel);
+               if (ret < 0)
+                       return -1;
+       }
+
+       return 0;
+}
+
+/****************************************************************************/
+static int process_olc(struct sk_buff **pskb, struct nf_conn *ct,
+                      enum ip_conntrack_info ctinfo,
+                      unsigned char **data, int dataoff,
+                      OpenLogicalChannel *olc)
+{
+       int ret;
+
+       DEBUGP("nf_ct_h323: OpenLogicalChannel\n");
+
+       if (olc->forwardLogicalChannelParameters.multiplexParameters.choice ==
+           eOpenLogicalChannel_forwardLogicalChannelParameters_multiplexParameters_h2250LogicalChannelParameters)
+       {
+               ret = process_h245_channel(pskb, ct, ctinfo, 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(pskb, ct, ctinfo, 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(pskb, ct, ctinfo, data, dataoff,
+                                 &olc->separateStack.networkAddress.
+                                 localAreaAddress);
+               if (ret < 0)
+                       return -1;
+       }
+
+       return 0;
+}
+
+/****************************************************************************/
+static int process_olca(struct sk_buff **pskb, struct nf_conn *ct,
+                       enum ip_conntrack_info ctinfo,
+                       unsigned char **data, int dataoff,
+                       OpenLogicalChannelAck *olca)
+{
+       H2250LogicalChannelAckParameters *ack;
+       int ret;
+
+       DEBUGP("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(pskb, ct, ctinfo, 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(pskb, ct, ctinfo, data, dataoff,
+                                             &ack->mediaChannel);
+                       if (ret < 0)
+                               return -1;
+               }
+
+               if (ack->options &
+                   eH2250LogicalChannelAckParameters_mediaControlChannel) {
+                       /* RTCP */
+                       ret = expect_rtp_rtcp(pskb, ct, ctinfo, data, dataoff,
+                                             &ack->mediaControlChannel);
+                       if (ret < 0)
+                               return -1;
+               }
+       }
+
+       return 0;
+}
+
+/****************************************************************************/
+static int process_h245(struct sk_buff **pskb, struct nf_conn *ct,
+                       enum ip_conntrack_info ctinfo,
+                       unsigned char **data, int dataoff,
+                       MultimediaSystemControlMessage *mscm)
+{
+       switch (mscm->choice) {
+       case eMultimediaSystemControlMessage_request:
+               if (mscm->request.choice ==
+                   eRequestMessage_openLogicalChannel) {
+                       return process_olc(pskb, ct, ctinfo, data, dataoff,
+                                          &mscm->request.openLogicalChannel);
+               }
+               DEBUGP("nf_ct_h323: H.245 Request %d\n",
+                      mscm->request.choice);
+               break;
+       case eMultimediaSystemControlMessage_response:
+               if (mscm->response.choice ==
+                   eResponseMessage_openLogicalChannelAck) {
+                       return process_olca(pskb, ct, ctinfo, data, dataoff,
+                                           &mscm->response.
+                                           openLogicalChannelAck);
+               }
+               DEBUGP("nf_ct_h323: H.245 Response %d\n",
+                      mscm->response.choice);
+               break;
+       default:
+               DEBUGP("nf_ct_h323: H.245 signal %d\n", mscm->choice);
+               break;
+       }
+
+       return 0;
+}
+
+/****************************************************************************/
+static int h245_help(struct sk_buff **pskb, 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 + IP_CT_IS_REPLY) {
+               return NF_ACCEPT;
+       }
+       DEBUGP("nf_ct_h245: skblen = %u\n", (*pskb)->len);
+
+       spin_lock_bh(&nf_h323_lock);
+
+       /* Process each TPKT */
+       while (get_tpkt_data(pskb, protoff, ct, ctinfo,
+                            &data, &datalen, &dataoff)) {
+               DEBUGP("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) {
+                       if (net_ratelimit())
+                               printk("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(pskb, ct, ctinfo, &data, dataoff, &mscm) < 0)
+                       goto drop;
+       }
+
+       spin_unlock_bh(&nf_h323_lock);
+       return NF_ACCEPT;
+
+      drop:
+       spin_unlock_bh(&nf_h323_lock);
+       if (net_ratelimit())
+               printk("nf_ct_h245: packet dropped\n");
+       return NF_DROP;
+}
+
+/****************************************************************************/
+static struct nf_conntrack_helper nf_conntrack_helper_h245 __read_mostly = {
+       .name                   = "H.245",
+       .me                     = THIS_MODULE,
+       .max_expected           = H323_RTP_CHANNEL_MAX * 4 + 2 /* T.120 */,
+       .timeout                = 240,
+       .tuple.dst.protonum     = IPPROTO_UDP,
+       .mask.src.u.udp.port    = __constant_htons(0xFFFF),
+       .mask.dst.protonum      = 0xFF,
+       .help                   = h245_help
+};
+
+/****************************************************************************/
+int get_h225_addr(struct nf_conn *ct, unsigned char *data,
+                 TransportAddress *taddr,
+                 union nf_conntrack_address *addr, __be16 *port)
+{
+       unsigned char *p;
+       int family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
+       int len;
+
+       switch (taddr->choice) {
+       case eTransportAddress_ipAddress:
+               if (family != AF_INET)
+                       return 0;
+               p = data + taddr->ipAddress.ip;
+               len = 4;
+               break;
+       case eTransportAddress_ip6Address:
+               if (family != AF_INET6)
+                       return 0;
+               p = data + taddr->ip6Address.ip6;
+               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 **pskb, struct nf_conn *ct,
+                      enum ip_conntrack_info ctinfo,
+                      unsigned char **data, int dataoff,
+                      TransportAddress *taddr)
+{
+       int dir = CTINFO2DIR(ctinfo);
+       int ret = 0;
+       __be16 port;
+       union nf_conntrack_address 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_conntrack_expect_alloc(ct)) == NULL)
+               return -1;
+       nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+                                &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)) &&
+           ct->status & IPS_NAT_MASK) {
+               /* NAT needed */
+               ret = nat_h245(pskb, ct, ctinfo, data, dataoff, taddr,
+                              port, exp);
+       } else {                /* Conntrack only */
+               if (nf_conntrack_expect_related(exp) == 0) {
+                       DEBUGP("nf_ct_q931: expect H.245 ");
+                       NF_CT_DUMP_TUPLE(&exp->tuple);
+               } else
+                       ret = -1;
+       }
+
+       nf_conntrack_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(union nf_conntrack_address *src,
+                                union nf_conntrack_address *dst,
+                                int family)
+{
+       struct flowi fl1, fl2;
+       int ret = 0;
+
+       memset(&fl1, 0, sizeof(fl1));
+       memset(&fl2, 0, sizeof(fl2));
+
+       switch (family) {
+       case AF_INET: {
+               struct rtable *rt1, *rt2;
+
+               fl1.fl4_dst = src->ip;
+               fl2.fl4_dst = dst->ip;
+               if (ip_route_output_key(&rt1, &fl1) == 0) {
+                       if (ip_route_output_key(&rt2, &fl2) == 0) {
+                               if (rt1->rt_gateway == rt2->rt_gateway &&
+                                   rt1->u.dst.dev  == rt2->u.dst.dev)
+                                       ret = 1;
+                               dst_release(&rt2->u.dst);
+                       }
+                       dst_release(&rt1->u.dst);
+               }
+               break;
+       }
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+       case AF_INET6: {
+               struct rt6_info *rt1, *rt2;
+
+               memcpy(&fl1.fl6_dst, src, sizeof(fl1.fl6_dst));
+               memcpy(&fl2.fl6_dst, dst, sizeof(fl2.fl6_dst));
+               rt1 = (struct rt6_info *)ip6_route_output(NULL, &fl1);
+               if (rt1) {
+                       rt2 = (struct rt6_info *)ip6_route_output(NULL, &fl2);
+                       if (rt2) {
+                               if (!memcmp(&rt1->rt6i_gateway, &rt2->rt6i_gateway,
+                                           sizeof(rt1->rt6i_gateway)) &&
+                                   rt1->u.dst.dev == rt2->u.dst.dev)
+                                       ret = 1;
+                               dst_release(&rt2->u.dst);
+                       }
+                       dst_release(&rt1->u.dst);
+               }
+               break;
+       }
+#endif
+       }
+       return ret;
+
+}
+
+/****************************************************************************/
+static int expect_callforwarding(struct sk_buff **pskb,
+                                struct nf_conn *ct,
+                                enum ip_conntrack_info ctinfo,
+                                unsigned char **data, int dataoff,
+                                TransportAddress *taddr)
+{
+       int dir = CTINFO2DIR(ctinfo);
+       int ret = 0;
+       __be16 port;
+       union nf_conntrack_address addr;
+       struct nf_conntrack_expect *exp;
+       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(&addr, &ct->tuplehash[!dir].tuple.src.u3,
+                                 ct->tuplehash[!dir].tuple.src.l3num)) {
+               DEBUGP("nf_ct_q931: Call Forwarding not tracked\n");
+               return 0;
+       }
+
+       /* Create expect for the second call leg */
+       if ((exp = nf_conntrack_expect_alloc(ct)) == NULL)
+               return -1;
+       nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+                                &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)) &&
+           ct->status & IPS_NAT_MASK) {
+               /* Need NAT */
+               ret = nat_callforwarding(pskb, ct, ctinfo, data, dataoff,
+                                        taddr, port, exp);
+       } else {                /* Conntrack only */
+               if (nf_conntrack_expect_related(exp) == 0) {
+                       DEBUGP("nf_ct_q931: expect Call Forwarding ");
+                       NF_CT_DUMP_TUPLE(&exp->tuple);
+               } else
+                       ret = -1;
+       }
+
+       nf_conntrack_expect_put(exp);
+
+       return ret;
+}
+
+/****************************************************************************/
+static int process_setup(struct sk_buff **pskb, struct nf_conn *ct,
+                        enum ip_conntrack_info ctinfo,
+                        unsigned char **data, int dataoff,
+                        Setup_UUIE *setup)
+{
+       int dir = CTINFO2DIR(ctinfo);
+       int ret;
+       int i;
+       __be16 port;
+       union nf_conntrack_address addr;
+       typeof(set_h225_addr_hook) set_h225_addr;
+
+       DEBUGP("nf_ct_q931: Setup\n");
+
+       if (setup->options & eSetup_UUIE_h245Address) {
+               ret = expect_h245(pskb, ct, ctinfo, 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) && ct->status && IPS_NAT_MASK &&
+           get_h225_addr(ct, *data, &setup->destCallSignalAddress,
+                         &addr, &port) &&
+           memcmp(&addr, &ct->tuplehash[!dir].tuple.src.u3, sizeof(addr))) {
+               DEBUGP("nf_ct_q931: set destCallSignalAddress "
+                      NIP6_FMT ":%hu->" NIP6_FMT ":%hu\n",
+                      NIP6(*(struct in6_addr *)&addr), ntohs(port),
+                      NIP6(*(struct in6_addr *)&ct->tuplehash[!dir].tuple.src.u3),
+                      ntohs(ct->tuplehash[!dir].tuple.src.u.tcp.port));
+               ret = set_h225_addr(pskb, 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) && ct->status & IPS_NAT_MASK &&
+           get_h225_addr(ct, *data, &setup->sourceCallSignalAddress,
+                         &addr, &port) &&
+           memcmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3, sizeof(addr))) {
+               DEBUGP("nf_ct_q931: set sourceCallSignalAddress "
+                      NIP6_FMT ":%hu->" NIP6_FMT ":%hu\n",
+                      NIP6(*(struct in6_addr *)&addr), ntohs(port),
+                      NIP6(*(struct in6_addr *)&ct->tuplehash[!dir].tuple.dst.u3),
+                      ntohs(ct->tuplehash[!dir].tuple.dst.u.tcp.port));
+               ret = set_h225_addr(pskb, 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(pskb, ct, ctinfo, data, dataoff,
+                                         &setup->fastStart.item[i]);
+                       if (ret < 0)
+                               return -1;
+               }
+       }
+
+       return 0;
+}
+
+/****************************************************************************/
+static int process_callproceeding(struct sk_buff **pskb,
+                                 struct nf_conn *ct,
+                                 enum ip_conntrack_info ctinfo,
+                                 unsigned char **data, int dataoff,
+                                 CallProceeding_UUIE *callproc)
+{
+       int ret;
+       int i;
+
+       DEBUGP("nf_ct_q931: CallProceeding\n");
+
+       if (callproc->options & eCallProceeding_UUIE_h245Address) {
+               ret = expect_h245(pskb, ct, ctinfo, 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(pskb, ct, ctinfo, data, dataoff,
+                                         &callproc->fastStart.item[i]);
+                       if (ret < 0)
+                               return -1;
+               }
+       }
+
+       return 0;
+}
+
+/****************************************************************************/
+static int process_connect(struct sk_buff **pskb, struct nf_conn *ct,
+                          enum ip_conntrack_info ctinfo,
+                          unsigned char **data, int dataoff,
+                          Connect_UUIE *connect)
+{
+       int ret;
+       int i;
+
+       DEBUGP("nf_ct_q931: Connect\n");
+
+       if (connect->options & eConnect_UUIE_h245Address) {
+               ret = expect_h245(pskb, ct, ctinfo, 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(pskb, ct, ctinfo, data, dataoff,
+                                         &connect->fastStart.item[i]);
+                       if (ret < 0)
+                               return -1;
+               }
+       }
+
+       return 0;
+}
+
+/****************************************************************************/
+static int process_alerting(struct sk_buff **pskb, struct nf_conn *ct,
+                           enum ip_conntrack_info ctinfo,
+                           unsigned char **data, int dataoff,
+                           Alerting_UUIE *alert)
+{
+       int ret;
+       int i;
+
+       DEBUGP("nf_ct_q931: Alerting\n");
+
+       if (alert->options & eAlerting_UUIE_h245Address) {
+               ret = expect_h245(pskb, ct, ctinfo, 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(pskb, ct, ctinfo, data, dataoff,
+                                         &alert->fastStart.item[i]);
+                       if (ret < 0)
+                               return -1;
+               }
+       }
+
+       return 0;
+}
+
+/****************************************************************************/
+static int process_information(struct sk_buff **pskb,
+                              struct nf_conn *ct,
+                              enum ip_conntrack_info ctinfo,
+                              unsigned char **data, int dataoff,
+                              Information_UUIE *info)
+{
+       int ret;
+       int i;
+
+       DEBUGP("nf_ct_q931: Information\n");
+
+       if (info->options & eInformation_UUIE_fastStart) {
+               for (i = 0; i < info->fastStart.count; i++) {
+                       ret = process_olc(pskb, ct, ctinfo, data, dataoff,
+                                         &info->fastStart.item[i]);
+                       if (ret < 0)
+                               return -1;
+               }
+       }
+
+       return 0;
+}
+
+/****************************************************************************/
+static int process_facility(struct sk_buff **pskb, struct nf_conn *ct,
+                           enum ip_conntrack_info ctinfo,
+                           unsigned char **data, int dataoff,
+                           Facility_UUIE *facility)
+{
+       int ret;
+       int i;
+
+       DEBUGP("nf_ct_q931: Facility\n");
+
+       if (facility->reason.choice == eFacilityReason_callForwarded) {
+               if (facility->options & eFacility_UUIE_alternativeAddress)
+                       return expect_callforwarding(pskb, ct, ctinfo, data,
+                                                    dataoff,
+                                                    &facility->
+                                                    alternativeAddress);
+               return 0;
+       }
+
+       if (facility->options & eFacility_UUIE_h245Address) {
+               ret = expect_h245(pskb, ct, ctinfo, 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(pskb, ct, ctinfo, data, dataoff,
+                                         &facility->fastStart.item[i]);
+                       if (ret < 0)
+                               return -1;
+               }
+       }
+
+       return 0;
+}
+
+/****************************************************************************/
+static int process_progress(struct sk_buff **pskb, struct nf_conn *ct,
+                           enum ip_conntrack_info ctinfo,
+                           unsigned char **data, int dataoff,
+                           Progress_UUIE *progress)
+{
+       int ret;
+       int i;
+
+       DEBUGP("nf_ct_q931: Progress\n");
+
+       if (progress->options & eProgress_UUIE_h245Address) {
+               ret = expect_h245(pskb, ct, ctinfo, 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(pskb, ct, ctinfo, data, dataoff,
+                                         &progress->fastStart.item[i]);
+                       if (ret < 0)
+                               return -1;
+               }
+       }
+
+       return 0;
+}
+
+/****************************************************************************/
+static int process_q931(struct sk_buff **pskb, struct nf_conn *ct,
+                       enum ip_conntrack_info ctinfo,
+                       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(pskb, ct, ctinfo, data, dataoff,
+                                   &pdu->h323_message_body.setup);
+               break;
+       case eH323_UU_PDU_h323_message_body_callProceeding:
+               ret = process_callproceeding(pskb, ct, ctinfo, data, dataoff,
+                                            &pdu->h323_message_body.
+                                            callProceeding);
+               break;
+       case eH323_UU_PDU_h323_message_body_connect:
+               ret = process_connect(pskb, ct, ctinfo, data, dataoff,
+                                     &pdu->h323_message_body.connect);
+               break;
+       case eH323_UU_PDU_h323_message_body_alerting:
+               ret = process_alerting(pskb, ct, ctinfo, data, dataoff,
+                                      &pdu->h323_message_body.alerting);
+               break;
+       case eH323_UU_PDU_h323_message_body_information:
+               ret = process_information(pskb, ct, ctinfo, data, dataoff,
+                                         &pdu->h323_message_body.
+                                         information);
+               break;
+       case eH323_UU_PDU_h323_message_body_facility:
+               ret = process_facility(pskb, ct, ctinfo, data, dataoff,
+                                      &pdu->h323_message_body.facility);
+               break;
+       case eH323_UU_PDU_h323_message_body_progress:
+               ret = process_progress(pskb, ct, ctinfo, data, dataoff,
+                                      &pdu->h323_message_body.progress);
+               break;
+       default:
+               DEBUGP("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(pskb, ct, ctinfo, data, dataoff,
+                                          &pdu->h245Control.item[i]);
+                       if (ret < 0)
+                               return -1;
+               }
+       }
+
+       return 0;
+}
+
+/****************************************************************************/
+static int q931_help(struct sk_buff **pskb, 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 + IP_CT_IS_REPLY) {
+               return NF_ACCEPT;
+       }
+       DEBUGP("nf_ct_q931: skblen = %u\n", (*pskb)->len);
+
+       spin_lock_bh(&nf_h323_lock);
+
+       /* Process each TPKT */
+       while (get_tpkt_data(pskb, protoff, ct, ctinfo,
+                            &data, &datalen, &dataoff)) {
+               DEBUGP("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) {
+                       if (net_ratelimit())
+                               printk("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(pskb, ct, ctinfo, &data, dataoff, &q931) < 0)
+                       goto drop;
+       }
+
+       spin_unlock_bh(&nf_h323_lock);
+       return NF_ACCEPT;
+
+      drop:
+       spin_unlock_bh(&nf_h323_lock);
+       if (net_ratelimit())
+               printk("nf_ct_q931: packet dropped\n");
+       return NF_DROP;
+}
+
+/****************************************************************************/
+static struct nf_conntrack_helper nf_conntrack_helper_q931[] __read_mostly = {
+       {
+               .name                   = "Q.931",
+               .me                     = THIS_MODULE,
+                                         /* T.120 and H.245 */
+               .max_expected           = H323_RTP_CHANNEL_MAX * 4 + 4,
+               .timeout                = 240,
+               .tuple.src.l3num        = AF_INET,
+               .tuple.src.u.tcp.port   = __constant_htons(Q931_PORT),
+               .tuple.dst.protonum     = IPPROTO_TCP,
+               .mask.src.l3num         = 0xFFFF,
+               .mask.src.u.tcp.port    = __constant_htons(0xFFFF),
+               .mask.dst.protonum      = 0xFF,
+               .help                   = q931_help
+       },
+       {
+               .name                   = "Q.931",
+               .me                     = THIS_MODULE,
+                                         /* T.120 and H.245 */
+               .max_expected           = H323_RTP_CHANNEL_MAX * 4 + 4,
+               .timeout                = 240,
+               .tuple.src.l3num        = AF_INET6,
+               .tuple.src.u.tcp.port   = __constant_htons(Q931_PORT),
+               .tuple.dst.protonum     = IPPROTO_TCP,
+               .mask.src.l3num         = 0xFFFF,
+               .mask.src.u.tcp.port    = __constant_htons(0xFFFF),
+               .mask.dst.protonum      = 0xFF,
+               .help                   = q931_help
+       },
+};
+
+/****************************************************************************/
+static unsigned char *get_udp_data(struct sk_buff **pskb, unsigned int protoff,
+                                  int *datalen)
+{
+       struct udphdr _uh, *uh;
+       int dataoff;
+
+       uh = skb_header_pointer(*pskb, protoff, sizeof(_uh), &_uh);
+       if (uh == NULL)
+               return NULL;
+       dataoff = protoff + sizeof(_uh);
+       if (dataoff >= (*pskb)->len)
+               return NULL;
+       *datalen = (*pskb)->len - dataoff;
+       return skb_header_pointer(*pskb, dataoff, *datalen, h323_buffer);
+}
+
+/****************************************************************************/
+static struct nf_conntrack_expect *find_expect(struct nf_conn *ct,
+                                              union nf_conntrack_address *addr,
+                                              __be16 port)
+{
+       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_conntrack_expect_find(&tuple);
+       if (exp && exp->master == ct)
+               return exp;
+       return NULL;
+}
+
+/****************************************************************************/
+static int set_expect_timeout(struct nf_conntrack_expect *exp,
+                             unsigned timeout)
+{
+       if (!exp || !del_timer(&exp->timeout))
+               return 0;
+
+       exp->timeout.expires = jiffies + timeout * HZ;
+       add_timer(&exp->timeout);
+
+       return 1;
+}
+
+/****************************************************************************/
+static int expect_q931(struct sk_buff **pskb, struct nf_conn *ct,
+                      enum ip_conntrack_info ctinfo,
+                      unsigned char **data,
+                      TransportAddress *taddr, int count)
+{
+       struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+       int dir = CTINFO2DIR(ctinfo);
+       int ret = 0;
+       int i;
+       __be16 port;
+       union nf_conntrack_address 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_conntrack_expect_alloc(ct)) == NULL)
+               return -1;
+       nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+                                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 && ct->status & IPS_NAT_MASK) {    /* Need NAT */
+               ret = nat_q931(pskb, ct, ctinfo, data, taddr, i, port, exp);
+       } else {                /* Conntrack only */
+               if (nf_conntrack_expect_related(exp) == 0) {
+                       DEBUGP("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_conntrack_expect_put(exp);
+
+       return ret;
+}
+
+/****************************************************************************/
+static int process_grq(struct sk_buff **pskb, struct nf_conn *ct,
+                      enum ip_conntrack_info ctinfo,
+                      unsigned char **data, GatekeeperRequest *grq)
+{
+       typeof(set_ras_addr_hook) set_ras_addr;
+
+       DEBUGP("nf_ct_ras: GRQ\n");
+
+       set_ras_addr = rcu_dereference(set_ras_addr_hook);
+       if (set_ras_addr && ct->status & IPS_NAT_MASK)  /* NATed */
+               return set_ras_addr(pskb, ct, ctinfo, data,
+                                   &grq->rasAddress, 1);
+       return 0;
+}
+
+/****************************************************************************/
+static int process_gcf(struct sk_buff **pskb, struct nf_conn *ct,
+                      enum ip_conntrack_info ctinfo,
+                      unsigned char **data, GatekeeperConfirm *gcf)
+{
+       int dir = CTINFO2DIR(ctinfo);
+       int ret = 0;
+       __be16 port;
+       union nf_conntrack_address addr;
+       struct nf_conntrack_expect *exp;
+
+       DEBUGP("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_conntrack_expect_alloc(ct)) == NULL)
+               return -1;
+       nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+                                &ct->tuplehash[!dir].tuple.src.u3, &addr,
+                                IPPROTO_UDP, NULL, &port);
+       exp->helper = nf_conntrack_helper_ras;
+
+       if (nf_conntrack_expect_related(exp) == 0) {
+               DEBUGP("nf_ct_ras: expect RAS ");
+               NF_CT_DUMP_TUPLE(&exp->tuple);
+       } else
+               ret = -1;
+
+       nf_conntrack_expect_put(exp);
+
+       return ret;
+}
+
+/****************************************************************************/
+static int process_rrq(struct sk_buff **pskb, struct nf_conn *ct,
+                      enum ip_conntrack_info ctinfo,
+                      unsigned char **data, RegistrationRequest *rrq)
+{
+       struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+       int ret;
+       typeof(set_ras_addr_hook) set_ras_addr;
+
+       DEBUGP("nf_ct_ras: RRQ\n");
+
+       ret = expect_q931(pskb, ct, ctinfo, 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 && ct->status & IPS_NAT_MASK) {
+               ret = set_ras_addr(pskb, ct, ctinfo, data,
+                                  rrq->rasAddress.item,
+                                  rrq->rasAddress.count);
+               if (ret < 0)
+                       return -1;
+       }
+
+       if (rrq->options & eRegistrationRequest_timeToLive) {
+               DEBUGP("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 **pskb, struct nf_conn *ct,
+                      enum ip_conntrack_info ctinfo,
+                      unsigned char **data, RegistrationConfirm *rcf)
+{
+       struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+       int dir = CTINFO2DIR(ctinfo);
+       int ret;
+       struct nf_conntrack_expect *exp;
+       typeof(set_sig_addr_hook) set_sig_addr;
+
+       DEBUGP("nf_ct_ras: RCF\n");
+
+       set_sig_addr = rcu_dereference(set_sig_addr_hook);
+       if (set_sig_addr && ct->status & IPS_NAT_MASK) {
+               ret = set_sig_addr(pskb, ct, ctinfo, data,
+                                       rcf->callSignalAddress.item,
+                                       rcf->callSignalAddress.count);
+               if (ret < 0)
+                       return -1;
+       }
+
+       if (rcf->options & eRegistrationConfirm_timeToLive) {
+               DEBUGP("nf_ct_ras: RCF TTL = %u seconds\n", rcf->timeToLive);
+               info->timeout = rcf->timeToLive;
+       }
+
+       if (info->timeout > 0) {
+               DEBUGP
+                   ("nf_ct_ras: set RAS connection timeout to %u seconds\n",
+                    info->timeout);
+               nf_ct_refresh(ct, *pskb, info->timeout * HZ);
+
+               /* Set expect timeout */
+               read_lock_bh(&nf_conntrack_lock);
+               exp = find_expect(ct, &ct->tuplehash[dir].tuple.dst.u3,
+                                 info->sig_port[!dir]);
+               if (exp) {
+                       DEBUGP("nf_ct_ras: set Q.931 expect "
+                              "timeout to %u seconds for",
+                              info->timeout);
+                       NF_CT_DUMP_TUPLE(&exp->tuple);
+                       set_expect_timeout(exp, info->timeout);
+               }
+               read_unlock_bh(&nf_conntrack_lock);
+       }
+
+       return 0;
+}
+
+/****************************************************************************/
+static int process_urq(struct sk_buff **pskb, struct nf_conn *ct,
+                      enum ip_conntrack_info ctinfo,
+                      unsigned char **data, UnregistrationRequest *urq)
+{
+       struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+       int dir = CTINFO2DIR(ctinfo);
+       int ret;
+       typeof(set_sig_addr_hook) set_sig_addr;
+
+       DEBUGP("nf_ct_ras: URQ\n");
+
+       set_sig_addr = rcu_dereference(set_sig_addr_hook);
+       if (set_sig_addr && ct->status & IPS_NAT_MASK) {
+               ret = set_sig_addr(pskb, ct, ctinfo, 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, *pskb, 30 * HZ);
+
+       return 0;
+}
+
+/****************************************************************************/
+static int process_arq(struct sk_buff **pskb, struct nf_conn *ct,
+                      enum ip_conntrack_info ctinfo,
+                      unsigned char **data, AdmissionRequest *arq)
+{
+       struct nf_ct_h323_master *info = &nfct_help(ct)->help.ct_h323_info;
+       int dir = CTINFO2DIR(ctinfo);
+       __be16 port;
+       union nf_conntrack_address addr;
+       typeof(set_h225_addr_hook) set_h225_addr;
+
+       DEBUGP("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] &&
+           set_h225_addr && ct->status & IPS_NAT_MASK) {
+               /* Answering ARQ */
+               return set_h225_addr(pskb, 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 && ct->status & IPS_NAT_MASK) {
+               /* Calling ARQ */
+               return set_h225_addr(pskb, data, 0,
+                                    &arq->srcCallSignalAddress,
+                                    &ct->tuplehash[!dir].tuple.dst.u3,
+                                    port);
+       }
+
+       return 0;
+}
+
+/****************************************************************************/
+static int process_acf(struct sk_buff **pskb, struct nf_conn *ct,
+                      enum ip_conntrack_info ctinfo,
+                      unsigned char **data, AdmissionConfirm *acf)
+{
+       int dir = CTINFO2DIR(ctinfo);
+       int ret = 0;
+       __be16 port;
+       union nf_conntrack_address addr;
+       struct nf_conntrack_expect *exp;
+       typeof(set_sig_addr_hook) set_sig_addr;
+
+       DEBUGP("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 && ct->status & IPS_NAT_MASK)
+                       return set_sig_addr(pskb, ct, ctinfo, data,
+                                           &acf->destCallSignalAddress, 1);
+               return 0;
+       }
+
+       /* Need new expect */
+       if ((exp = nf_conntrack_expect_alloc(ct)) == NULL)
+               return -1;
+       nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+                                &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_conntrack_expect_related(exp) == 0) {
+               DEBUGP("nf_ct_ras: expect Q.931 ");
+               NF_CT_DUMP_TUPLE(&exp->tuple);
+       } else
+               ret = -1;
+
+       nf_conntrack_expect_put(exp);
+
+       return ret;
+}
+
+/****************************************************************************/
+static int process_lrq(struct sk_buff **pskb, struct nf_conn *ct,
+                      enum ip_conntrack_info ctinfo,
+                      unsigned char **data, LocationRequest *lrq)
+{
+       typeof(set_ras_addr_hook) set_ras_addr;
+
+       DEBUGP("nf_ct_ras: LRQ\n");
+
+       set_ras_addr = rcu_dereference(set_ras_addr_hook);
+       if (set_ras_addr && ct->status & IPS_NAT_MASK)
+               return set_ras_addr(pskb, ct, ctinfo, data,
+                                   &lrq->replyAddress, 1);
+       return 0;
+}
+
+/****************************************************************************/
+static int process_lcf(struct sk_buff **pskb, struct nf_conn *ct,
+                      enum ip_conntrack_info ctinfo,
+                      unsigned char **data, LocationConfirm *lcf)
+{
+       int dir = CTINFO2DIR(ctinfo);
+       int ret = 0;
+       __be16 port;
+       union nf_conntrack_address addr;
+       struct nf_conntrack_expect *exp;
+
+       DEBUGP("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_conntrack_expect_alloc(ct)) == NULL)
+               return -1;
+       nf_conntrack_expect_init(exp, ct->tuplehash[!dir].tuple.src.l3num,
+                                &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_conntrack_expect_related(exp) == 0) {
+               DEBUGP("nf_ct_ras: expect Q.931 ");
+               NF_CT_DUMP_TUPLE(&exp->tuple);
+       } else
+               ret = -1;
+
+       nf_conntrack_expect_put(exp);
+
+       /* Ignore rasAddress */
+
+       return ret;
+}
+
+/****************************************************************************/
+static int process_irr(struct sk_buff **pskb, struct nf_conn *ct,
+                      enum ip_conntrack_info ctinfo,
+                      unsigned char **data, InfoRequestResponse *irr)
+{
+       int ret;
+       typeof(set_ras_addr_hook) set_ras_addr;
+       typeof(set_sig_addr_hook) set_sig_addr;
+
+       DEBUGP("nf_ct_ras: IRR\n");
+
+       set_ras_addr = rcu_dereference(set_ras_addr_hook);
+       if (set_ras_addr && ct->status & IPS_NAT_MASK) {
+               ret = set_ras_addr(pskb, ct, ctinfo, data,
+                                  &irr->rasAddress, 1);
+               if (ret < 0)
+                       return -1;
+       }
+
+       set_sig_addr = rcu_dereference(set_sig_addr_hook);
+       if (set_sig_addr && ct->status & IPS_NAT_MASK) {
+               ret = set_sig_addr(pskb, ct, ctinfo, data,
+                                       irr->callSignalAddress.item,
+                                       irr->callSignalAddress.count);
+               if (ret < 0)
+                       return -1;
+       }
+
+       return 0;
+}
+
+/****************************************************************************/
+static int process_ras(struct sk_buff **pskb, struct nf_conn *ct,
+                      enum ip_conntrack_info ctinfo,
+                      unsigned char **data, RasMessage *ras)
+{
+       switch (ras->choice) {
+       case eRasMessage_gatekeeperRequest:
+               return process_grq(pskb, ct, ctinfo, data,
+                                  &ras->gatekeeperRequest);
+       case eRasMessage_gatekeeperConfirm:
+               return process_gcf(pskb, ct, ctinfo, data,
+                                  &ras->gatekeeperConfirm);
+       case eRasMessage_registrationRequest:
+               return process_rrq(pskb, ct, ctinfo, data,
+                                  &ras->registrationRequest);
+       case eRasMessage_registrationConfirm:
+               return process_rcf(pskb, ct, ctinfo, data,
+                                  &ras->registrationConfirm);
+       case eRasMessage_unregistrationRequest:
+               return process_urq(pskb, ct, ctinfo, data,
+                                  &ras->unregistrationRequest);
+       case eRasMessage_admissionRequest:
+               return process_arq(pskb, ct, ctinfo, data,
+                                  &ras->admissionRequest);
+       case eRasMessage_admissionConfirm:
+               return process_acf(pskb, ct, ctinfo, data,
+                                  &ras->admissionConfirm);
+       case eRasMessage_locationRequest:
+               return process_lrq(pskb, ct, ctinfo, data,
+                                  &ras->locationRequest);
+       case eRasMessage_locationConfirm:
+               return process_lcf(pskb, ct, ctinfo, data,
+                                  &ras->locationConfirm);
+       case eRasMessage_infoRequestResponse:
+               return process_irr(pskb, ct, ctinfo, data,
+                                  &ras->infoRequestResponse);
+       default:
+               DEBUGP("nf_ct_ras: RAS message %d\n", ras->choice);
+               break;
+       }
+
+       return 0;
+}
+
+/****************************************************************************/
+static int ras_help(struct sk_buff **pskb, unsigned int protoff,
+                   struct nf_conn *ct, enum ip_conntrack_info ctinfo)
+{
+       static RasMessage ras;
+       unsigned char *data;
+       int datalen = 0;
+       int ret;
+
+       DEBUGP("nf_ct_ras: skblen = %u\n", (*pskb)->len);
+
+       spin_lock_bh(&nf_h323_lock);
+
+       /* Get UDP data */
+       data = get_udp_data(pskb, protoff, &datalen);
+       if (data == NULL)
+               goto accept;
+       DEBUGP("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) {
+               if (net_ratelimit())
+                       printk("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(pskb, ct, ctinfo, &data, &ras) < 0)
+               goto drop;
+
+      accept:
+       spin_unlock_bh(&nf_h323_lock);
+       return NF_ACCEPT;
+
+      drop:
+       spin_unlock_bh(&nf_h323_lock);
+       if (net_ratelimit())
+               printk("nf_ct_ras: packet dropped\n");
+       return NF_DROP;
+}
+
+/****************************************************************************/
+static struct nf_conntrack_helper nf_conntrack_helper_ras[] __read_mostly = {
+       {
+               .name                   = "RAS",
+               .me                     = THIS_MODULE,
+               .max_expected           = 32,
+               .timeout                = 240,
+               .tuple.src.l3num        = AF_INET,
+               .tuple.src.u.udp.port   = __constant_htons(RAS_PORT),
+               .tuple.dst.protonum     = IPPROTO_UDP,
+               .mask.src.l3num         = 0xFFFF,
+               .mask.src.u.udp.port    = __constant_htons(0xFFFF),
+               .mask.dst.protonum      = 0xFF,
+               .help                   = ras_help,
+       },
+       {
+               .name                   = "RAS",
+               .me                     = THIS_MODULE,
+               .max_expected           = 32,
+               .timeout                = 240,
+               .tuple.src.l3num        = AF_INET6,
+               .tuple.src.u.udp.port   = __constant_htons(RAS_PORT),
+               .tuple.dst.protonum     = IPPROTO_UDP,
+               .mask.src.l3num         = 0xFFFF,
+               .mask.src.u.udp.port    = __constant_htons(0xFFFF),
+               .mask.dst.protonum      = 0xFF,
+               .help                   = ras_help,
+       },
+};
+
+/****************************************************************************/
+static void __exit nf_conntrack_h323_fini(void)
+{
+       nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[1]);
+       nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
+       nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
+       nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
+       kfree(h323_buffer);
+       DEBUGP("nf_ct_h323: fini\n");
+}
+
+/****************************************************************************/
+static int __init nf_conntrack_h323_init(void)
+{
+       int ret;
+
+       h323_buffer = kmalloc(65536, GFP_KERNEL);
+       if (!h323_buffer)
+               return -ENOMEM;
+       ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[0]);
+       if (ret < 0)
+               goto err1;
+       ret = nf_conntrack_helper_register(&nf_conntrack_helper_q931[1]);
+       if (ret < 0)
+               goto err2;
+       ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[0]);
+       if (ret < 0)
+               goto err3;
+       ret = nf_conntrack_helper_register(&nf_conntrack_helper_ras[1]);
+       if (ret < 0)
+               goto err4;
+       DEBUGP("nf_ct_h323: init success\n");
+       return 0;
+
+err4:
+       nf_conntrack_helper_unregister(&nf_conntrack_helper_ras[0]);
+err3:
+       nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[1]);
+err2:
+       nf_conntrack_helper_unregister(&nf_conntrack_helper_q931[0]);
+err1:
+       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");